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Einstein, Andrew Jeffrey

0000-0003-2583-9278

Mayo Clinic

NewYork–Presbyterian Hospital

Citations 12

Beyond BMI: an interpretable integrated body composition index from low-dose chest CT for all-cause mortality risk stratification: a multicentre study
Patel, Krishna K., Miller, Robert J.H, Marcinkiewicz, Anna M , Kamagate, Assiata, Shanbhag, Aakash, Hijazi, Waseem , Lemley, Mark, Zhou, Jianhang, Liang, Joanna X. , Ramirez, Giselle, Mostafavi, Shiva , Urs, Meghana, Travin, Mark, Alexanderson, Erick, Caraval-Juarez, Isabel, Ruddy, Terrence D., Einstein, Andrew J., Feher, Attila, Le, Viet T, Mason, Steve, Calsavara, Vinicius F., Chareonthaitawee, Panithaya, Wopperer, Samuel, Wang, Lixia, Li, Debiao, Lopez-Ramirez, Felipe, Berman, Daniel S., Kwieciński, Jacek , Dey, Damini, Carli, Marcelo Di, Li, Debiao , Miller, Robert J.H. , Miller, Robert J H , Li, Debiao , Yi, Jirong , Lemley, Mark , Zhou, Jianhang , Urs, Meghana , Spielvogel, Clemens P. , Slipczuk, Leandro , Travin, Mark I. , Alexanderson, Erick , Packard, René R. Sevag , Al‐Mallah, Mouaz H. , Ruddy, Terrence D , Einstein, Andrew Jeffrey , Feher, Attila , Miller, Edward J. , Acampa, Wanda , Knight, Stacey , Le, Viet T. , Mason, Steve, Calsavara, Vinicius F , Chareonthaitawee, Panithaya , Kwan, Alan C. , Li, Debiao, Fishman, Elliot K. , Lopez-Ramirez, Felipe, Berman, Daniel S. , Dey, Damini , Carli, Marcelo F. Di , Slomka, Piotr J

No container title available | August 10, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.08.05.26359437 Get It

Summary Background Body composition is recognized as a major determinant of health outcomes, but its multidimensional nature makes clinical adoption challenging. We sought to develop and validate a body composition index (BCI) for all-cause mortality risk assessment, integrating variables of six body composition tissues. Methods We analyzed 28509 consecutive patients undergoing myocardial perfusion imaging with routine low-dose chest CT attenuation correction (CTAC) scans acquired during myocardial perfusion imaging (MPI) at 12 centers across four countries. An artificial intelligence-based BCI was developed in a cohort of 15037 patients’ CTACs by integrating the CT-derived metrics of bone, skeletal muscle, and four adipose tissue compartments, coronary artery calcium score, and basic demographic variables (age, sex, BMI). The performance of BCI for mortality prediction was validated in an internal cohort of 6444 patients and an external cohort of 7028 patients by prognosis, calibration, net benefit, and explainability. Model-based simulation of tissue metrics modification was performed to evaluate estimated mortality risk reduction. Findings During a median of 3.5 (IQR [1.9, 5.1]) years, 4697 (16%) patients died. In the external testing cohort, the BCI demonstrated excellent discrimination for mortality (area under receiver operating characteristic curve 0.78 (95% CI [0.76, 0.79]) and Harrell’s concordance index 0.75 [0.73, 0.76]), calibration, and net benefit overall and across pre-specified subgroups stratified by patient characteristics and imaging protocols. Visceral adipose tissue attenuation was the most influential body composition measure, followed by skeletal muscle volume. Simulated improvement in body composition was associated with significant mortality risk reduction. Interpretation An index combining six body composition measures obtained opportunistically from routine chest CT provides robust mortality risk stratification. By converting complex body composition information into a single interpretable score, the BCI can facilitate clinical implementation of opportunistic CT biomarkers and guide individualized preventive strategies. Funding National Institute of Health Research in context Evidence before this study We searched PubMed and Google Scholar on July 7, 2026 for English language studies using the terms (“mortality prediction” OR “death prediction”) AND (“integrated body composition analysis” OR “body composition metrics integration”) AND (“predictive model” OR “model development”), and identified 41 publications describing predictive models incorporating body composition metrics. Recent advances in artificial intelligence (AI) have enabled increasingly granular quantification of body composition from CT, with multiple tissues and tissue-specific metrics showing independent prognostic value for all-cause mortality (ACM) prediction. However, reported associations of body composition metrics with mortality risk were highly inconsistent or even contradictory across studies. This heterogeneity likely reflected the differences in study design or the inherent complexity of body composition analysis, such as the interaction among variables derived from multiple tissues. Thus, it is difficult to interpret body composition results reliably in clinical practice. We hypothesized that integrating multiple body composition metrics could achieve comprehensive and reliable prediction of mortality across patient populations. Added value of this study In this large international, multicenter longitudinal cohort study of 28509 consecutive patients with suspected or known coronary artery disease (CAD) undergoing myocardial perfusion imaging across 12 sites in four countries, we developed and externally validated an artificial intelligence-based body composition index (BCI) for all-cause mortality prediction. The BCI integrated chest CT-derived metrics of six body composition tissue compartments – bone, skeletal muscle (SM), subcutaneous adipose tissue (SAT), intramuscular adipose tissue (IMAT), visceral adipose tissue (VAT), and epicardial adipose tissue (EAT), together with demographics (age, sex, BMI) and CT-derived coronary artery calcium (CAC) score, all derived automatically from routine low-dose attenuation correction CT scans without additional imaging or laboratory tests. In an external validation cohort of 7028 patients, the BCI achieved robust discrimination for mortality prediction, substantially outperforming a baseline model using demographics and calcium score alone, and exceeded the discriminative performance of prior body composition models. Performance was consistent across subgroups defined by sex, age, body mass index, cardiometabolic risk factors, imaging modality, and acquisition protocol, supporting generalizability across clinical settings. The BCI demonstrated excellent calibration and net clinical benefit. Explainability analysis identified visceral adipose tissue attenuation and skeletal muscle volume as the dominant contributors to mortality risk, offering tissue-specific therapeutic targets that complement generic weight-based metrics. Model-based simulations suggested that improvements in these specific compartments could reduce estimated mortality risk more effectively than equivalent changes in BMI alone, pointing toward precision therapeutic targets beyond weight reduction. Our study improved over previous literatures on body composition-based predictive models in one or more of the following ways: (1) we considered six types of body composition tissues while existing studies considered only three or less tissues, thus significantly higher granularity and improved ability to capture refined tissue interactions; (2) our model was rigorously validated in external sites, showing cross-site generalizability while most previous work lacked external validation; (3) our model achieved significant prediction performance improvement over previous body composition predictive models, offering better clinical outcomes prediction and facilitating the suitability for widespread clinical adoption; (4) our study was conducted with a large multi-center cohort across multiple countries, achieving statistical power and demonstrating reliability towards patients characteristics and imaging acquisition protocols while previous studies involved small single-center cohorts; (5) our model required only CT scans and basic demographics which were widely available in clinical routine while the existing models required dedicated laboratory tests or specialized imaging modalities, enhancing the applicability in routine clinical practice. Implications of all the available evidence BCI offers an explainable and clinically deployable tool for improved prediction of mortality risk from existing chest CT scans. Its use could inform updates to existing risk models, guide precision preventive strategies, and support development of therapeutics targeting specific body composition phenotypes.
Quantitative single photon emission computed tomography/computed tomography of Tc-99m-pyrophosphate scans: metrics for short-term risk stratification in transthyretin cardiac amyloidosis
Pleasure, Mitchell , Jackson, Candace L. , DeLuca, Albert, Kinkhabwala, Mona, Liu, Qi, Chernovolenko, Margarita , Wats, Karan , Brailovsky, Yevgeniy, Maurer, Mathew S., Johnson, Lynne L. , Poterucha, Timothy J. , Einstein, Andrew Jeffrey , Castillo, Michelle , Kinkhabwala, Mona, Ruberg, Frederick L. , Elias, Pierre , Poterucha, Timothy Joseph

Nuclear Medicine Communications | July 13, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1097/mnm.0000000000002199 Get It

Background Radionuclide SPECT/computed tomography (CT) is standard for diagnosing transthyretin cardiac amyloidosis (ATTR-CM), but the prognostic value of quantitative metrics remains incompletely defined. We investigated their prognostic utility and additive value beyond existing staging systems. Methods Retrospective study of patients undergoing technetium-99m-pyrophosphate (PYP) SPECT/CT, including consecutive clinically referred patients (October 2023 to 2024) and trial participants with positive scans from January 2022. Myocardial PYP was quantified using standardized uptake values (SUV mean and SUV max ) and volumetric measures [percent injected dose (%ID), cardiac amyloid activity (CAA)]. Major adverse cardiovascular events (MACEs) comprised heart failure hospitalization or death. Cox and Kaplan–Meier analyses assessed associations; likelihood ratio testing and change in area under the curve (AUC) evaluated the additive prognostic value to existing staging systems. Results Among 43 patients with ATTR-CM, 16 experienced MACE over a median 518 days. AUCs ranged from 0.74 to 0.88 at 3 months and 0.56–0.62 at 12 months. All variables trended toward association with MACE: SUV mean ( P = 0.02), SUV max ( P = 0.03), %ID ( P = 0.06), and CAA ( P = 0.06). After age adjustment, cut-points for SUV max (5.8) and SUV mean (3.5) remained associated with MACE. Adding imaging variables to the National Amyloidosis Centre and Columbia staging systems did not significantly improve prognostic accuracy (Δ χ 2 : 0.40–2.48, P = 0.11–0.53). Interobserver reproducibility was high (intraclass correlation coefficients = 0.89–0.99). Conclusion Quantitative Tc-99m–PYP SPECT/CT metrics were associated with short-term outcomes in ATTR-CM, but did not improve established staging systems. Findings are hypothesis-generating and require validation in larger cohorts.
Automated AI-Based Aortic Measurements From Attenuation Correction CT as an Adjunctive Cardiovascular Risk Biomarker: An International Multicenter Study
Marcinkiewicz, Anna M , Shanbhag, Aakash , Chareonthaitawee, Panithaya , Zhang, Wenhao, Jilaihawi, Hasan , Zaid, Ryan , Cadet, Sebastien , Ramirez, Giselle , Lemley, Mark , Yi, Jirong , Hijazi, Waseem , Liang, Joanna X. , Fehér, Attila , Mason, Steve, Alexanderson, Erick, Carvajal-Juarez, Isabel , Travin, Mark I. , Rosamond, Thomas, Wopperer, Samuel , Berman, Daniel S. , Carli, Marcelo F. Di , Al-Jilaihawi, Hasanian , Builoff, Valerie , Calsavara, Vinicius F , Einstein, Andrew Jeffrey , Miller, Edward J , Feher, Attila , Ruddy, Terrence D , Le, Viet T , Knight, Stacey , Carvajal-Juarez, Isabel , Slipczuk, Leandro , Rosamond, Thomas L , Wopperer, Samuel , Berman, Daniel , Dey, Damini , Di Carli, Marcelo F , Miller, Robert J H , Slomka, Piotr J , Chareonthaitawee, Panithaya , Lemley, Mark , Ramirez, Giselle , Shanbhag, Aakash , Zaid, Ryan , Miller, Edward J. , Le, Viet T. , Mason, Steve, Knight, Stacey , Alexanderson, Erick , Slipczuk, Leandro , Dey, Damini , Miller, Robert J.H.

Circulation: Cardiovascular Imaging | July 2, 2026 | Volume: 19 | Issue: 7 | Pages: No page available

10.1161/circimaging.125.019726 Get It

BACKGROUND: Aortic enlargement is a powerful predictor of dissection and rupture, yet it is rarely evaluated during routine myocardial perfusion imaging, despite the widespread availability of computed tomography (CT) attenuation correction scans. The aim of this study was to determine whether fully automated, opportunistically derived, artificial intelligence-based aortic measurements from myocardial perfusion imaging CT attenuation correction scans are associated with adverse outcomes in a large multicenter cohort. METHODS: CT attenuation correction scans from patients undergoing positron emission tomography/CT and single-photon emission CT/CT myocardial perfusion imaging across 10 centers were included. A deep learning model automatically segmented the thoracic aorta, and a postprocessing algorithm extracted maximum ascending and descending diameters. The aortic size index was calculated by indexing the diameter to body surface area. RESULTS: A total of 29 339 patients (56% men; median age, 66 years [interquartile range, 58–75 years]) were included. Over a median follow-up of 3.5 years (interquartile range, 1.9–5.0 years), 5083 (17.3%) patients died. Median ascending and descending aortic size index values were 1.8 cm/m 2 (interquartile range, 1.6–2.0) and 1.5 cm/m 2 (interquartile range, 1.4–1.6), respectively, with an increase with age and higher values in females. Elevated aortic size index thresholds (ascending >2.2 cm/m 2 ; descending >1.6 cm/m 2 ) were significantly associated with increased all-cause mortality (ascending: adjusted hazard ratio, 1.16 [95% CI, 1.07–1.26], P <0.001; descending: adjusted hazard ratio, 1.23 [95% CI, 1.14–1.31]; P <0.001). Notably, the prognostic value of an abnormal aortic size index persisted independent of age, sex, and perfusion abnormalities. CONCLUSIONS: Artificial intelligence can unlock previously unused information within routine myocardial perfusion imaging CT attenuation correction scans by rapidly and automatically quantifying aortic size at scale. Opportunistic aortic measurements derived from CT attenuation correction may serve as an adjunctive risk biomarker and could add prognostic value to standard myocardial perfusion imaging without additional imaging or radiation.
Incremental Prognostic Value of Subendocardial Myocardial Flow Reserve in Patients With Normal Perfusion
Lopez, Diana M. , Brown, Jenifer M. , Divakaran, Sanjay , Weber, Brittany , Hainer, Jon , Carre, Sylvain, Lemley, Mark , Ramirez, Giselle , Shanbhag, Aakash , Kavanagh, Paul, Liang, Joanna X. , Blankstein, Ron , Dorbala, S, Mason, Steve, Wopperer, Samuel , Rosamond, Thomas, Kwieciński, Jacek , Travin, Mark I. , Alexanderson, Erick, Packard, René R S, Feher, A, Sanghani, Rupa, deKemp, Robert A. , Berman, Daniel S. , Slomka, P J, Carli, Marcelo F. Di , Packard, René R. Sevag , Lopez, Diana M , Huck, Daniel , Weber, Brittany , Hainer, Jon , Lemley, Mark , Ramirez, Giselle , Shanbhag, Aakash , Kavanagh, Paul , Blankstein, Ron , Dorbala, Sharmila , Dey, Damini , Knight, Stacey , Le, Viet T , Wopperer, Samuel , Chareonthaitawee, Panithaya , Rosamond, Thomas L , Kwiecinski, Jacek , Miller, Robert J H , Slipczuk, Leandro , Carvajal-Juarez, Isabel , Packard, Rene R S , Al-Mallah, Mouaz H , Einstein, Andrew Jeffrey , Feher, Attila , Acampa, Wanda , Buechel, Ronny R , deKemp, Robert A , Berman, Daniel , Slomka, Piotr J , Di Carli, Marcelo F , Divakaran, Sanjay , Brown, Jenifer Michelle , Kavanagh, Paul , Dey, Damini , Knight, Stacey , Le, Viet T. , Mason, Steve, Chareonthaitawee, Panithaya , Miller, Robert J.H. , Slipczuk, Leandro , Alexanderson, Erick , Carvajal-Juarez, Isabel , Al‐Mallah, Mouaz H. , Sanghani, Rupa Mehta

Circulation | June 4, 2026 | Volume: 154 | Issue: 3 | Pages: 212-222

10.1161/circulationaha.125.078816 Get It

BACKGROUND: Although the prognostic utility of positron emission tomography (PET) myocardial flow reserve (MFR) is well established, emerging data suggest that reduced subendocardial flows also predict adverse outcomes. However, the incremental value of subendocardial MFR (MFR SE ) beyond transmural MFR (MFR TM ) remains unclear. METHODS: We studied patients in a multicenter PET registry with normal perfusion on stress/rest Rb-82 PET, excluding those with a previous history of coronary artery bypass surgery, heart transplantation, or left ventricular ejection fraction <40%. The optimal MFR SE cutoff for predicting major adverse cardiovascular events (MACEs; death, myocardial infarction [MI], revascularization, or heart failure [HF] hospitalization) was determined using Youden’s index. Patients were stratified into 3 groups: concordant-normal (MFR TM ≥2.0; MFR SE ≥2.1), discordant (low-MFR SE , normal MFR TM ), and abnormal MFR TM . Clinical outcomes were compared by MFR groups. RESULTS: Among 6603 patients (normal N=4103; discordant N=885; abnormal N=1615) the mean age was 66.3±12.4 years, and 54% were women. Compared with the concordant-normal group, patients with discordant low-MFR SE were older and more likely to have hypertension, diabetes, peripheral artery disease, and previous percutaneous coronary intervention. The median MFR TM for normal, discordant, and abnormal groups were 2.86, 2.15, and 1.72, respectively. Over a median follow-up of 4.9 years, 1661 MACE events occurred. Discordant low-MFR SE patients had a higher risk of MACE (hazard ratio [HR], 1.41; 95% CI, 1.22–1.64) and all-cause mortality (HR, 1.36; 95% CI, 1.14–1.61) compared with concordant-normal patients. The discordant group had an intermediate absolute risk of MACE, with an adjusted annualized event rate of 5.79% (95% CI, 5.10–6.49) compared with 3.99% (95% CI, 3.67–4.30; P <0.001) in the concordant-normal group and 8.35% (95% CI, 7.71–9.00; P <0.001) in the abnormal MFR TM group. CONCLUSIONS: Subendocardial MFR reveals clinically meaningful risk heterogeneity among patients with preserved transmural flow reserve, helping refine risk stratification beyond traditional PET metrics.
Opportunistic CT Attenuation Biomarkers of Anemia Are Associated With Impaired Myocardial Flow Reserve and Cardiovascular Outcomes
Miller, Robert J.H. , Shanbhag, Aakash, Kwieciński, Jacek , Kavanagh, Paul, Ramirez, Giselle, Lemley, Mark, Kamagate, Assiata, Slipczuk, Leandro , Travin, Mark I. , Alexanderson, Erick, Carvajal-Juarez, Isabel, Packard, René R S, Einstein, Andrew J., Mason, Steve, Wopperer, Samuel, Rosamond, Thomas, DeKemp, Robert A, Buechel, Ronny R. , Berman, Daniel S., Dey, Damini, Carli, Marcelo F Di, Slomka, Piotr, Carvajal-Juarez, Isabel , Slipczuk, Leandro , Packard, Rene R S , Al-Mallah, Mouaz H , Buechel, Ronny R , Di Carli, Marcelo F , Slomka, Piotr J , Carvajal-Juarez, Isabel , Miller, Robert J H , Yi, Jirong , Kavanagh, Paul , Lemley, Mark , Alexanderson, Erick , Packard, René R. Sevag , Al‐Mallah, Mouaz H. , Einstein, Andrew Jeffrey , Acampa, Wanda , Knight, Stacey , Le, Viet T. , Mason, Steve, Wopperer, Samuel, Chareonthaitawee, Panithaya , deKemp, Robert A. , Berman, Daniel S. , Dey, Damini , Carli, Marcelo F. Di

No container title available | May 19, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.05.14.26353239 Get It

ABSTRACT Background Anemia is an established marker of cardiovascular disease severity and risk which leads to elevations in resting myocardial blood flow (MBF) and impaired myocardial flow reserve (MFR) in patients without obstructive coronary artery disease (CAD). Anemia can potentially be detected opportunistically from blood pool density changes on computed tomography (CT) imaging. Objectives We evaluated relationships between chamber density measurements with hemoglobin, positron emission tomography (PET) findings, and cardiovascular events. Methods We included 33460 patients from 13 sites in the REFINE-PET who underwent PET and 24368 patients undergoing lung cancer screening chest CT. A deep learning model segmented cardiac chambers from CT images, then quantified chamber density. We evaluated the relationship between chamber density measures with resting MBF and MFR, as well as associations with death or myocardial infarction (MI). Results We included a total of 57,828 patients. A higher density in myocardium compared to left ventricle blood pool was associated with reduced MFR (adjusted odds ratio 3.02 per SD increase, 95% confidence interval[CI] 2.72 – 3.38) and an increased risk of death or MI in (adjusted hazard ratio[HR] 1.38 per SD increase, 95% CI 1.26-1.51). Having myocardial density higher than blood pool density was also associated with cardiovascular death in patients undergoing low-dose chest CT (adjusted HR 1.73, 95% CI 1.20-2.52). Conclusions In a large multimodality dataset, lower cardiac chamber density is associated with impaired MFR and independently associated with cardiovascular events. These biomarkers can be automatically extracted from CT to provide physiologic insights and potentially guide patient care. CONDENSED ABSTRACT Anemia is an important marker of cardiovascular disease severity and predictor of cardiovascular events. We utilized deep learning to measure cardiac chamber density on computed tomography imaging as a surrogate for anemia in 57,828 patients from two large multicenter studies. A higher density in myocardium compared to left ventricle blood pool was associated with reduced MFR and an increased risk of death or MI in patients undergoing positron emission tomography, and an increased risk of cardiovascular death in patients undergoing low-dose computed tomography. These biomarkers can provide additionally physiologic insights which could be used to guide patient care.
CT Attenuation Map–Derived Body Composition Is Associated with Cardiorespiratory Fitness in Multicenter External Validation
Miller, Robert J.H. , Yi, Jirong, Shanbhag, Aakash, Feher, Attila, Miller, Edward J. , Ramirez, Giselle, Travin, Mark I. , Carvajal-Juarez, Isabel, Packard, René R S, Al-Mallah, M., Mason, Steve, Wopperer, Samuel, Buechel, R M, Rosamond, Thomas, Berman, Daniel S., Dey, Damini, Carli, Marcelo F. Di , Slomka, Piotr, Buechel, Ronny R. , Carvajal-Juarez, Isabel , Miller, Edward J , Slipczuk, Leandro , Packard, Rene R S , Al-Mallah, Mouaz H , Buechel, Ronny R , Slomka, Piotr J , Carvajal-Juarez, Isabel , Miller, Robert J H , Patel, Krishna , Ruddy, Terrence D , Einstein, Andrew Jeffrey , Feher, Attila , Liang, Joanna X., Slipczuk, Leandro , Alexanderson, Erick , Packard, René R. Sevag , Al‐Mallah, Mouaz H. , Acampa, Wanda , Knight, Stacey , Le, Viet T. , Mason, Steve, Wopperer, Samuel, Chareonthaitawee, Panithaya , Berman, Daniel S. , Dey, Damini

No container title available | May 8, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.05.07.26352573 Get It

ABSTRACT Aims Exercise capacity is a powerful predictor of cardiovascular risk. In patients unable to exercise, body composition analysis can potentially be used to estimate cardiorespiratory fitness. We developed a body composition “fitness” score, then validated its utility in two external populations. Methods and Results We included patients from four sites undergoing single photon emission computed tomography (SPECT) and twelve sites undergoing positron emission tomography (PET). We quantified body composition using deep learning. We evaluated associations between body composition and good exercise capacity (defined as completing ≥7 minutes on a Bruce protocol) then developed a body composition “fitness” score. We then assessed the associations of “fitness” score with exercise capacity and all-cause mortality in external populations. In total, 36471 patients were included with median age 67 (interquartile range 58 – 74). Median skeletal muscle density was higher among patients with good exercise capacity. In the external SPECT population, the body composition “fitness” score had higher prediction performance for good exercise capacity (AUC 0.771, 95% CI 0.752 – 0.789) than age (AUC 0.717, p<0.01). In the external PET population, high body composition “fitness” score was associated with lower cardiovascular death (adjusted hazard ratio 0.70, 95% CI 0.62 – 0.79, p<0.001). Conclusions We demonstrated that a comprehensive body composition “fitness” score could identify patients with good cardiorespiratory fitness. This approach transforms routinely acquired CT data into a surrogate marker of fitness which can be applied in patients undergoing PET, or other CT imaging, where exercise testing is not performed. Graphical Abstract Overview of study design. The overall population (n=36471) was split as outlined above. Body composition was analyzed from available computed tomography imaging. The distribution of body composition measures were analyzed in the combined single photon emission computed tomography (SPECT) populations. A body composition “fitness” score was derived to predict good exercise capacity in the internal population, with associations assessed in the two external testing populations.
Hidden risk in normal myocardial perfusion scans: AI-detected proximal coronary calcium on CT attenuation maps improves prognosis
Zhou, Jianhang, Miller, Robert JH, Shanbhag, Aakash , Killekar, Aditya , Han, D, Patel, Krishna K., Pieszko, Konrad , Yi, Jirong , Urs, Meghana , Ramirez, Giselle, Lemley, M A R K, Kavanagh, P A U L, Liang, Joanna X , Kamagate, Assiata, Builoff, V A L E R I, Einstein, A N D R E W, Feher, Attila, Sinusas, AJ, Le, Viet T, Mason, Steve, Wopperer, Samuel, Alexanderson, Erick, Carvajal-Juarez, Isabel, Rosamond, Thomas, Travin, Mark I. , Packard, René RS, deKemp, Robert A. , Buechel, Ronny R. , Berman, Daniel S. , Carli, Marcelo F. Di , Carvajal-Juarez, Isabel , Carvajal-Juarez, Isabel , Buechel, Ronny R , Shanbhag, Aakash , Zhou, Jianhang , Miller, Robert J.H. , Lemley, Mark , Kavanagh, Paul , Liang, Joanna X. , Builoff, Valerie , Einstein, Andrew Jeffrey , Feher, Attila , Miller, Edward J , Sinusas, Albert J. , Ruddy, Terrence D , Knight, Stacey , Le, Viet T. , Mason, Steve, Chareonthaitawee, Panithaya , Wopperer, Samuel, Alexanderson, Erick , Slipczuk, Leandro , Packard, René R. Sevag , Acampa, Wanda , Al‐Mallah, Mouaz H. , Dey, Damini , Slomka, Piotr J

No container title available | April 15, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.04.14.26350808 Get It

Abstract Purpose Spatial distribution of coronary artery calcium (CAC) may provide additional prognostic value in patients undergoing SPECT and PET myocardial perfusion imaging (MPI). We aimed to automatically identify CAC in proximal segments from attenuation correction CT (CTAC) scans using artificial intelligence (AI) and to evaluate prognostic significance in two large international multicenter registries. Methods From hybrid MPI/CT imaging (N=43,099) across 15 sites, we included 4,552 most relevant patients with 1) no prior coronary artery disease; 2) AI-derived mild CAC scores (1-99); and 3) normal perfusion (stress total perfusion deficit <5%). The independent associations between AI-identified proximal CAC and major adverse cardiovascular events (MACE) and all-cause mortality (ACM) were evaluated using multivariable Cox regression, likelihood ratio test (LRT), and continuous net reclassification index (NRI). Results Among the patients with mild CAC and normal perfusion (mean age 65±12 years, 51% male), 1,730 (38%) had proximal CAC. Over 3.6 (inter-quartile interval 2.1, 5.2) years follow-up, 599 (13%) and 444 (10%) patients had MACE or ACM, respectively. Proximal CAC was associated with an increased risk of MACE (adjusted hazard ratio [HR] 1.24, 95% CI 1.03–1.48, P=0.02) and ACM (adjusted HR 1.25, 95% CI 1.01–1.53, P=0.04) after the adjustment of CAC score and density, clinical risk factors, and perfusion deficit. Proximal CAC improved the risk stratification of MACE (LRT P=0.02; NRI 12%) and ACM (LRT P=0.04; NRI 12%). Conclusion In patients with mild CAC and normal perfusion, AI detection of proximal CAC identified a higher-risk group for adverse outcomes, highlighting its prognostic utility. Graphical Abstract From patients who underwent hybrid myocardial perfusion imaging (MPI) from 15 sites, we analyzed those without prior coronary artery disease (CAD), mild coronary artery calcium (CAC) scores (1-99), and normal perfusion (stress total perfusion deficit <5%). A previously developed AI model was used to identify CAC lesions in proximal coronary segments on CT attenuation correction maps (CTAC). We evaluated associations with major adverse cardiovascular events (MACE) and all-cause mortality (ACM), showing risk stratification of proximal CAC and improvement by net reclassification index (NRI). CAC lesion color: green, left anterior descending artery (LAD) with left main artery; red, left circumflex artery (LCX); yellow, right coronary artery (RCA). Adjusted hazard ratios (HRs) are shown with 95% confidence intervals.
Multicenter Evaluation of Myocardial Flow Reserve as a Prognostic Marker for Mortality in 13 N-Ammonia PET Myocardial Perfusion Imaging
Ramirez, Giselle, Builoff, Valerie , Miller, R., Lemley, Mark , Carvajal-Juarez, Isabel, Alexanderson, Erick, Rosamond, Thomas, Song, Na , Travin, Mark I. , Slipczuk, Leandro, Wopperer, Samuel, Carli, Marcelo F. Di, Chareonthaitawee, Panithaya, Slomka, Piotr J, Slipczuk, Leandro , Miller, Robert J.H. , Carvajal-Juarez, Isabel , Miller, Robert J H , Carvajal-Juarez, Isabel , Slipczuk, Leandro , Einstein, Andrew Jeffrey , Wopperer, Samuel B., Di Carli, Marcelo F , Chareonthaitawee, Panithaya , Slomka, Piotr J , Lemley, Mark , Alexanderson, Erick , Wopperer, Samuel, Carli, Marcelo F. Di , Chareonthaitawee, Panithaya

Circulation: Cardiovascular Imaging | January 30, 2026 | Volume: 19 | Issue: 4 | Pages: No page available

10.1161/circimaging.125.018729 Get It

BACKGROUND: Myocardial flow reserve (MFR), measured by positron emission tomography (PET) myocardial perfusion imaging, provides valuable information on epicardial coronary disease, diffuse atherosclerosis, and microvascular function. Despite its routine use, the prognostic efficacy of 13 N-ammonia PET MFR remains unconfirmed in larger multicenter cohorts of patients with suspected or known coronary artery disease. METHODS: We considered patients from 5 sites in the REFINE PET (Registry of Flow and Perfusion Imaging for Artificial Intelligence with PET) registry who underwent 13 N-ammonia PET myocardial perfusion imaging for coronary artery disease. Clinical and imaging data were collected at the time of myocardial perfusion imaging. MFR was quantified as the ratio of stress to rest myocardial blood flow, using QPET software (Cedars-Sinai Medical Center, Los Angeles, CA). The primary outcome was all-cause mortality. Survival analyses were performed using Kaplan-Meier and Cox regression models adjusted for clinical and imaging covariates. RESULTS: In total, 6277 patients were included (median age of 65 years, 56% male). Median follow-up time was 3.8 years. There were 1895 patients with MFR ≤2 and 4382 with MFR >2. Patients with MFR ≤2 had significantly higher mortality than those with MFR >2 (n=701 [37.0%] versus n=537 [12.3%], respectively; P <0.001). Annualized all-cause mortality rates by MFR and summed stress score ranged from 1.7 to 15.8. In multivariable analysis, MFR ≤2 was independently associated with increased all-cause mortality in the overall population (hazard ratio, 2.70 [95% CI, 2.41–3.03]; P <0.001), even among patients with no perfusion defects (hazard ratio, 2.36 [95% CI, 1.93–2.89]; P <0.001). Mortality risk decreased across increasing MFR deciles, ranging from hazard ratio, 2.73 (95% CI, 2.39–3.11) to hazard ratio, 0.35 (95% CI, 0.25–0.49). CONCLUSIONS: In this large multicenter cohort, MFR derived from 13 N-ammonia PET myocardial perfusion imaging is a strong, independent predictor of all-cause mortality, even in patients with normal perfusion. An MFR of ≤2 identifies elevated risk, while higher values are associated with improved survival. These findings support the routine integration of MFR to enhance risk stratification in patients with suspected or known coronary artery disease.
Age- and Sex-Adjusted Myocardial Flow Reserve Percentiles for Personalized Cardiovascular Risk Assessment
Joseph, Lee , Trinquart, Ludovic , Lopez, Diana M. , Brandao, Simone , Brown, Jenifer M. , Divakaran, Sanjay , Huck, Daniel , Weber, Brittany N, Goldstein, Leanne Barrett , Hainer, J., Carre, Sylvain , Lemley, M A R K, Orozco, Giselle Ramirez, Blankstein, R., Dorbala, Sharmila, Alexanderson, Erick, Carvajal-Juarez, Isabel, Mason, Steve, Wopperer, Samuel, Rosamond, Thomas, Buechel, Ronny R. , Al-Mallah, Mouaz H, Travin, Mark I. , Berman, Daniel, Dey, D A M I N I, Slomka, PJ, Carli, M. Di, Dey, Damini , Divakaran, Sanjay , Hainer, Jon , Carvajal-Juarez, Isabel , Joseph, Lee , Hainer, Jon , Blankstein, Ron , Dorbala, Sharmila , Alexanderson, Erick , Carvajal-Juarez, Isabel , Acampa, Wanda , Packard, Rene R S , Rosamond, Thomas L , Buechel, Ronny R , Einstein, Andrew Jeffrey , Al-Mallah, Mouaz H , Slipczuk, Leandro , Slomka, Piotr J , Dey, Damini , Lopez, Diana M., Soares Brandão, Simone Cristina , Brown, Jenifer Michelle , Lemley, Mark , Liang, Jiaming , Packard, René R. Sevag , Le, Viet T. , Mason, Steve, Knight, Stacey , Chareonthaitawee, Panithaya , Wopperer, Samuel, Al‐Mallah, Mouaz H. , Slipczuk, Leandro , Berman, Daniel S.

No container title available | December 31, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2025.12.30.25343223 Get It

ABSTRACT Introduction Positron emission tomography (PET) myocardial flow reserve (MFR) is a robust indicator of coronary vascular health and a strong predictor of cardiovascular risk. Clinical guidelines typically use fixed MFR thresholds (e.g., <2.0) to stratify risk, yet this approach overlooks individual variation, particularly by age and sex. We aimed to establish age- and sex-adjusted MFR percentiles and to evaluate their prognostic and predictive performance for cardiovascular risk assessment, in comparison with conventional fixed-threshold MFR approach. Methods Using data from the REFINE PET registry (24,820 patients from 12 sites), we measured PET MFR and derived age- and sex-adjusted MFR reference percentiles using quantile regression in patients without known coronary artery disease. All patients were categorized into percentile-based quartile groups. The primary outcome for prognostic and prediction analyses was major adverse cardiovascular events (MACE), defined as all-cause mortality, myocardial infarction, or heart-failure hospitalization. Time-to-event associations were evaluated using covariate-adjusted survival models, with cumulative incidence and hazard ratios (HR) estimated at 1 and 5 years in the derivation dataset, an independent but similar validation dataset A, and a high-risk validation dataset B. Predictive performance for MACE was assessed using discrimination, calibration, and reclassification metrics, comparing percentile-based models with models using a fixed MFR threshold (<2.0). Results Among participants (mean age 66.5 years; median follow-up 3.6 years), age- and sex-adjusted MFR quartile groups were strong independent predictors of MACE, with adjusted HR increasing stepwise across quartile groups at both early and later follow-up. At 1 year, HR (95% CI) comparing the lowest to the highest quartile group were 4.06 (3.41–4.82) in the derivation cohort, 3.31 (2.32–4.71) in validation cohort A, and 2.35 (2.05–2.70) in validation cohort B. At 5 years, the corresponding HR were 2.18 (1.86–2.56), 1.77 (1.31–2.40), and 1.59 (1.36–1.86). Percentile-based models demonstrated consistently higher discrimination, better calibration, and greater net reclassification for MACE at both time points compared with fixed-threshold MFR models. Although 67.2% of patients had preserved MFR (>2.0), cardiovascular risk increased steadily across MFR percentiles even within this range. Conclusion Age- and sex-adjusted MFR percentiles provide a reliable, clinically actionable measure of vascular health, improving cardiovascular risk stratification by better capturing age- and sex-related heterogeneity in vascular risk. Compared with traditional fixed-threshold approaches, MFR percentiles demonstrate improved predictive performance for cardiovascular risk assessment across diverse patient populations. CLINICAL PERSPECTIVE What is new? In a large, multinational real-world registry of more than 24,000 patients undergoing PET MPI, we derived age- and sex-adjusted myocardial flow reserve (MFR) percentiles, establishing a lifespan-based reference framework with age-specific reference values. Age- and sex-adjusted MFR percentiles showed a strong, graded association with 1- and 5-year cardiovascular risk and demonstrated improved prognostic and predictive performance compared with fixed MFR thresholds and models without MFR across independent derivation and validation datasets, including a higher-risk cohort. Lower adjusted MFR percentiles were consistently associated with higher risk of major adverse cardiovascular events, including all-cause mortality, myocardial infarction, and heart-failure hospitalization. What are the clinical implications? Age- and sex-adjusted MFR percentiles provide a personalized, dynamic measure of coronary vascular health that improves cardiovascular risk stratification by accounting for age- and sex-related heterogeneity. A percentile-based approach may help clinicians better identify patients at elevated cardiovascular risk who may warrant closer monitoring or intensified preventive strategies, while avoiding unnecessary intervention in lower-risk individuals. By integrating macrovascular and microvascular dysfunction, age- and sex-adjusted MFR percentiles offer a clinically interpretable marker of vascular aging that may inform future research on aging biomarkers, novel therapeutics and cardiovascular risk assessment across the spectrum of atherosclerotic and microvascular disease.
Detecting Transthyretin Cardiac Amyloidosis With Artificial Intelligence
Jain, Sneha S. , Sun, Tony , Pierson, Emma , Oliver, F. , Malta, Paloma P , Castillo, Michelle , Wan, Ningxin, Alishetti, Shudhanshu , Finer, Joshua , Brown, Kathleen LaRow , Ramlall, Vijendra , Elhadad, Noémie , Rodríguez, Fátima , Homma, Shunichi, Poterucha, Timothy J. , Poterucha, Timothy Joseph , Hartman, Heidi S. , Tatonetti, Nicholas P. , Witteles, Ronald , Goyal, Parag , Einstein, Andrew Jeffrey , Maurer, Matthew J. , Elias, Pierre

JAMA Cardiology | November 10, 2025 | Volume: 11 | Issue: 2 | Pages: 117

10.1001/jamacardio.2025.4591 Get It

Importance Transthyretin amyloid cardiomyopathy (ATTR-CM) is underdiagnosed despite expanding treatment options. Objective To develop and evaluate an artificial intelligence (AI)–augmented clinical program for ATTR-CM detection. Design, Setting, and Participants This nonrandomized clinical trial involved constructing an AI model, ATTRACTnet, using electrocardiogram waveforms, echocardiographic measurements, demographics, and diagnosis codes for orthopedic manifestations of amyloidosis. A single-system, multisite, single-arm, open-label trial was conducted to evaluate its real-world performance. The model was trained and validated at a large academic referral site for ATTR-CM with external validation at an academic site. The trial was conducted as a single-system, multisite trial. Patients with left ventricular (LV) wall thickness 12 mm or more and an ATTRACTnet score 0.5 or higher were eligible. Exclusions included prior ATTR-CM testing, hypertrophic cardiomyopathy, expected life span less than 1 year, nursing home residence, advanced dementia, or LV wall thickness less than 14 mm explained by uncontrolled hypertension or moderate/severe aortic stenosis. Intervention Eligible patients were notified and offered nuclear scintigraphy testing, monoclonal protein testing, and follow-up care on agreement from the treating physician. Main Outcomes and Measure The primary outcome was a diagnosis of ATTR-CM by consensus criteria. ATTR-CM testing positivity was compared with historical and contemporary controls. Results ATTRACTnet was developed in an internal test set of 799 patients (mean [SD] age, 75.1 [11.1] years; 516 [64.7%] male and 283 [35.3%] female) using 5-fold cross-validation with an additional external test set of 422 patients. It had good discrimination for ATTR-CM detection with an area under the receiver operator characteristic curve of 0.85 (5-fold cross-validation, 0.77-0.85) in the internal set and 0.82 (95% CI, .81-0.83) in the external test set with similar performance in Hispanic, non-Hispanic Black, and non-Hispanic White patients. A total of 1471 patients were identified with positive AI model scores 0.5 or more during the study period, with 256 eligible patients who met study criteria. Of these patients, 50 underwent amyloidosis testing after physician and patient approval; 24 (48%) were diagnosed with ATTR-CM, and 21 (88%) initiated treatment within 3 months. The positivity rate was more than 2.8 times higher than historical controls (15.3%; 95% CI, 13.1%-17.9%; P &amp;lt; .001), with an 18% relative increase in new diagnoses vs the prior year. Conclusions and Relevance AI-augmented screening may improve ATTR-CM detection and identify patients who are missed by usual care. Prospective randomized trials are needed to determine if outcomes are improved. Trial Registration ClinicalTrials.gov Identifier: NCT06469372