Kane, Garvan C.

Background: Tricuspid regurgitation (TR) is associated with significant morbidity, but individualized treatment and timing of intervention are yet to be defined. We previously proposed and validated artificial intelligence electrocardiography (AI-ECG) scores for various diseases. Whether incorporating AI-ECG information adds to risk stratification above and beyond classical clinical parameters is unknown. Objectives: To identify AI-ECG scores independently associated with all-cause mortality in chronic TR and to create a composite AI-ECG risk score. Methods: Patients with a first echocardiographic diagnosis of ≥moderate TR between 2005-2016 and an ECG within ±15 days were included. The Tricuspid Regurgitation Impact on Outcome (TRIO) score was calculated as previously described based on 8 simple parameters (age, sex, severe TR, heart failure, lung disease, heart rate, creatinine and AST). AI-ECG probabilities of low ejection fraction, aortic stenosis, amyloid, cirrhosis, atrial fibrillation and hypertrophic cardiomyopathy were estimated by existing algorithms; the first 4 were associated with all-cause mortality and a composite AI-ECG risk score was calculated (0-4; 1 point for each AI-ECG above specific threshold). Results: A total of 12,377 pts were included (age 72±13 yrs, 55% women). Over a median follow-up of 1.3 yrs (IQR 0.1 to 4.4), 7,121 pts (58%) died. Mortality risk increased significantly with higher composite AI-ECG risk score (Fig. 1A). On multivariable analysis (proportional hazards method), the composite AI-ECG risk score remained independently associated with death, even after adjusting for age, sex, high NT-proBNP levels (>2,500 pg/mL), right ventricular systolic pressure (RVSP), diuretic use and TRIO risk score category (Fig. 1B). Conclusions: Patients with ≥moderate TR show progressively worse survival with increasing composite AI-ECG risk score. Incorporating AI-derived information from a simple and inexpensive ECG may identify patients with the highest risk of mortality beyond clinical risk scores as TRIO or classical clinical, laboratory and echocardiographic parameters. Prospective validation of this approach needs to be tested in future trials.

Abstract Aims Chronotropic incompetence (CI) is a biomarker of cardiac autonomic dysfunction. The aim of the study is to assess the risk stratification value of CI during exercise or pharmacological stress echocardiography in patients with chronic coronary syndromes. Methods and results In a prospective, multicenter, international, observational study, we enrolled 13 445 patients with known or suspected chronic coronary syndromes who underwent stress echocardiography in 19 clinical sites from 10 countries using either exercise (n = 2594), dobutamine (n = 2440), or dipyridamole (n = 8411). Heart rate was automatically measured from the 1-lead ECG in the echocardiography monitor. We considered CI as failure to reach 85% of the maximal predicted (220-age) heart rate for exercise and dobutamine, and heart rate reserve (peak/rest heart rate) ≤ 1.22 (≤1.17 if in permanent atrial fibrillation) for dipyridamole stress. The primary outcome was all-cause death. CI was observed in 5045 patients (38%) and stress-induced regional wall motion abnormalities in 1648 (13%). Over a median follow-up time of 3.4 years (interquartile range, 1.6–9.1 years), there were 2426 (18%) deaths. The 10-year mortality was 39% in patients with and 21% in patients without CI (P < 0.0001). CI was associated with a significant increase in 10-year mortality in all age groups ranging from ≤54 years to ≥75 years (P < 0.0001). In addition, it was associated with increased mortality (P < 0.0001) irrespective of β-blocker use. Cox multivariable analysis revealed that CI was an independent predictor of mortality (HR: 1.60, 95% confidence interval: 1.47–1.74; P < 0.0001) together with age, male sex, diabetes mellitus, left ventricular ejection fraction, and resting heart rate. Conclusion In patients with chronic coronary syndromes, CI during exercise or pharmacological stress is a simple and objective predictor of survival.

Background Atrial fibrillation (AF) impacts management decisions in valvular heart disease but its significance in patients with chronic aortic regurgitation (AR) is not well established. Objectives To evaluate the prevalence and prognostic role of AF in patients with chronic, haemodynamically significant AR. Methods Adults with chronic ≥moderate-to-severe AR, from March 2004 to April 2019, were retrospectively identified. Those with acute AR, moderate or worse other valve disease or prior valve surgery were excluded. Patients with AF were identified based on 12-lead ECGs, 1-lead ECGs (showing AF for ≥30 s), or episodes recorded by implanted cardiac devices. Primary outcome was all-cause mortality. Cox regression models were used to assess associations with mortality: model 1 adjusted for age, symptoms (New York Heart Association class II–IV), Charlson Comorbidity Index, left ventricle (LV) end-systolic volume index and AF; model 2 added left atrial volume index and model 3 further added systolic pulmonary artery pressure. Results Of the 1006 included patients (age 59±18 years; 822 (82%) men), 446 (46%) had hypertension and 364 (36%) had a bicuspid aortic valve. AF was present in 161 (16%) patients at the time of ≥moderate-to-severe AR diagnosis. During a median follow-up of 1.6 years (IQR 0.2–6.2), AF was associated with an increased mortality risk in univariate and in all three multivariable models (HR 1.61 (95% CI 1.07 to 2.43), HR 2.21 (95% CI 1.31 to 3.72) and HR 2.06 (95% CI 1.21 to 3.52), respectively), including after propensity matching (HR 1.58 (95% CI 1.01 to 2.48)). Conclusions AF is present in one in six patients with chronic≥moderate-to-severe AR and is associated with an increased risk of mortality even after adjusting for measures of LV systolic and diastolic function. There is a need for future prospective studies to validate these findings and evaluate AF as a potential trigger for early surgery.

Background Tricuspid valve surgery is recommended for severe isolated tricuspid regurgitation (TR) if symptoms persist despite optimal medical therapy. The definition of optimal therapy for TR is unclear beyond managing underlying conditions. Diuretics are the primary treatment for volume retention in TR, but it is unknown whether a “safe diuretic dose” exists for conservative management. We sought to evaluate the association between diuretic dose and outcomes. Methods Adult patients with ≥moderate–severe isolated TR were retrospectively identified from echocardiographic reports. Clinical and echocardiographic data were extracted from electronic medical records and manually reviewed. The primary end point was all‐cause mortality. Loop diuretic doses were converted to furosemide equivalent and categorized into 4 groups: <40 mg, 40 to 79 mg, 80 to 159 mg, and ≥160 mg daily. Results Of 1302 patients (age 72±13 years, 60% female), 565 (43%) had moderate–severe TR and 737 (57%) had severe TR. Median follow‐up was 8.7 (1.4, 14.0) years. Comorbidities increased with higher diuretic doses. A linear relationship between diuretic dose and mortality was observed in spline‐curve analysis. Hazard ratios (and CIs) for mortality adjusted for age, sex, coronary disease, chronic kidney disease, mild pulmonary hypertension, and New York Heart Association III/IV symptoms were 1.21 (0.96–1.53) ( P =0.12) for <40 mg, 1.50 (1.23–1.82) ( P <0.001) for 40 to 79 mg, 1.86 (1.46–2.37) ( P <0.001) for 80 to 159 mg, and 2.90 (2.18–3.88) ( P <0.001) for ≥160 mg furosemide equivalent. Any diuretic dose was associated with significant symptoms (New York Heart Association III–IV), with more patients experiencing symptoms at higher doses. Conclusion A daily loop diuretic dose ≥40 mg furosemide equivalent is associated with increased mortality and greater symptom severity in patients with TR.

Abstract Aims Tricuspid valve regurgitation (TR) is common and associated with increased mortality. The interaction between the pulmonary artery (PA) circulation and the right ventricle (RV) and association with outcomes is incompletely understood. The effective PA elastance (PA Ea) is a composite measure of RV afterload that refers to the pulmonary vascular load that the RV must overcome to eject blood. Whether PA Ea discriminates mortality risk in unselected patients with significant TR is unknown. Methods and results In consecutive patients with ≥moderate TR, we compared all-cause mortality at 5 years based on the PA Ea (defined as the RV systolic pressure/stroke volume as measured by transthoracic echocardiography). In a total of 12 682 patients, the median PA Ea was 0.7 mm Hg/mL (interquartile range 0.5, 0.9). Increasing levels of PA Ea were associated with heart failure, liver and kidney disease, and clinical markers of risk such as the Tricuspid Regurgitation Impact on Outcomes score. Increasing levels of PA Ea were associated with larger RVs, worse RV systolic function, higher N-terminal pro-brain natriuretic peptide levels, and greater degrees of right heart failure. After adjusting for age and sex, PA Ea was associated with higher risk of death (hazard ratio 1.55 per 0.5 mm Hg/mL change of PA Ea; 95% confidence intervals 1.51–1.60; P &lt; 0.0001). In multivariable modelling incorporating available clinical variables, PA Ea was independently predictive of outcome compared with other indexes of RV–PA coupling. Conclusion In patients with significant TR, higher PA Ea is progressively associated with RV dysfunction, right heart failure, and worse survival. Incorporating PA Ea into the routine echo assessment may help stratify risk.

Background Right ventricular (RV) maladaptation to elevated pulmonary afterload is the primary determinant of outcomes in pulmonary artery (PA) hypertension; however, the pathobiological mechanisms underlying RV decompensation remain poorly understood. Methods We performed global untargeted metabolomics on plasma from 55 patients who underwent gold‐standard RV‐PA coupling measurements using multibeat pressure volume loop assessment in a single‐center cohort and from 1027 patients with coupling surrogate measurements in a larger multicenter cohort, the PVDOMICS (Pulmonary Vascular Disease Phenomics) study. Age and sex‐adjusted linear regression was performed to identify associations between metabolites and coupling metrics. Additionally, we performed a metabolic flux analysis using gene expression data from RV tissue in an independent cohort of 32 patients. Partial least squares–discriminant analysis was used to identify metabolites and reactions characteristic of the decompensated RV. Results RV‐PA coupling was negatively associated with tricarboxylic acid (TCA) cycle intermediate levels. Specifically, plasma α‐ketoglutarate and fumarate were significantly associated with all coupling metrics in both cohorts. Metabolic flux analysis indicated that decompensated RVs exhibited aberrant TCA cycle activity, including reduced acetyl coenzyme A entry and increased lactate elimination, suggesting a shift from the TCA cycle toward glycolysis at the RV tissue level. Conclusions We identify an association between circulating TCA cycle intermediate levels and RV‐PA uncoupling in 2 independent cohorts, and dysregulated TCA cycle metabolism in decompensated PA hypertension RVs, suggesting that aberrant TCA cycle metabolism could represent a hallmark of RV maladaptation in PA hypertension. Further study of this pathway is warranted to develop novel biomarkers of RV function or RV‐targeted therapies.

INTRODUCTION: Cardiovascular disease is a leading cause of maternal mortality. Our aim was to evaluate the feasibility and quality of artificial intelligence (AI)-guided focused cardiac ultrasound (FoCUS) by novice scanners to screen for left ventricular (LV) systolic dysfunction in pregnant individuals. METHODS: Patients were prospectively enrolled during routine obstetric appointments. FoCUS images were acquired by individuals without scanning or clinical experience using AI-guided image acquisition software (UltraSight) on a Philips Lumify device. Standard two-dimensional imaging views were attempted: parasternal long axis (PSLA), parasternal short axis mid-level (PSSA Mid), apical four chamber (A4C), three chamber (A3C), and two chamber (A2C). Two experienced cardiologists reviewed all images and graded diagnostic quality: poor, adequate, good, excellent. RESULTS: A total of 101 pregnant participants were enrolled; median age was 32 (interquartile range [IQR], 29, 35) years. The median gestational age was 23 (IQR, 16, 31) weeks; 16% first trimester, 45% second, and 39% third. The most feasible views were the PSLA and PSSA Mid, 98% and 97% with adequate or greater image quality, respectively. A3C and A2C were least feasible, acquired in 34% and 40% with adequate or greater image quality in 28% and 35%, respectively. Average scan time was 6 minutes, 46 seconds ± 0.2. The LV ejection fraction could be determined for the entire cohort and was normal (50–75%) for all. CONCLUSIONS/IMPLICATIONS: Implementation of AI-guided FoCUS in pregnant individuals is feasible, even in the absence of an experienced sonographer. This approach could allow for low-cost screening and early diagnosis of LV systolic dysfunction during pregnancy.

Over the past decade, stress echocardiography has evolved from a test for assessing epicardial artery stenosis to a comprehensive functional test, targeting multiple cardiovascular parameters. The new approach includes several structured steps: (a) evaluating regional wall motion abnormalities to detect epicardial artery stenosis or vasospasm; (b) assessing pulmonary congestion and diastolic function via B-lines with lung ultrasound; (c) gauging preload and contractile reserve with volumetric echocardiography; (d) measuring coronary microvascular reserve using Doppler-based coronary flow velocity in the middistal left anterior descending artery; and (e) determining cardiac sympathetic reserve by tracking heart rate reserve on an ECG. This evolution was supported extensively by the Italian Society of Echocardiography and Cardiovascular Imaging (SIECVI), which played a key role in five areas: (1) developing the initial, curiosity-driven project; (2) disseminating protocols and results at national and international conferences, supporting logistic infrastructure and publication expenses; (3) establishing a digital platform (customized Redcap) for data entry and storage; (4) facilitating patient recruitment across 19 Italian centers; and (5) offering formal endorsement through six presidencies, adding credibility and reach beyond any single institution. The protocol quickly advanced from concept to high-impact publications, earning inclusion in 2024 specialty guidelines. Initially Italian-led, the study now includes 50 centers across 20 countries (e.g. USA and China). Beyond the 50 peer-reviewed papers published in 2016–2024, this study offers a novel, sustainable approach to cardiac stress testing, providing more information at lower costs, with zero radiation and minimal environmental impact. SIECVI’s endorsement was instrumental in amplifying the study’s rigor and outreach.

Abstract Aims To develop a deep learning model that: (i) utilizes transthoracic echocardiography (TTE) clips to detect left ventricular (LV) enlargement without being provided information regarding a patient’s sex and body size; and (ii) can be accurately applied to clips acquired using either standard comprehensive TTE or handheld cardiac ultrasound (HCU). Methods and results Using retrospective TTE data (training: 8722 patients; internal validation: 468 patients), we developed a deep learning model that estimates a patient’s end-diastolic LV volume (indexed to body surface area and normalized across the sexes), and then thresholds this estimate to perform the following classifications: (1) normally sized LV vs. ≥ mild LV enlargement; (2) normal/mildly enlarged LV vs. ≥ moderate LV enlargement. For retrospective datasets, the model showed strong performance in TTE across three geographically distinct locations (Minnesota and Wisconsin: 1082 patients, AUC = 0.925 and 0.953 for classifications 1 and 2, respectively; Arizona: 1475 patients, AUC = 0.935 and 0.969; and Florida: 1481 patients, AUC = 0.934 and 0.970). Additionally, performance was strong for both TTE and HCU clips collected from a prospective cohort of 410 patients who underwent HCU immediately following TTE (TTE: AUC = 0.925 and 0.971; HCU: AUC = 0.874 and 0.902, for classifications 1 and 2, respectively). Conclusion An automated deep learning model applied to TTE or HCU images accurately categorizes LV volumes. These results lay a foundation for future work aimed at optimizing clinical outcomes for heart failure patients by enabling early detection of LV enlargement across various point-of-care settings.

Abstract Aims Left ventricular (LV) ventricular-arterial coupling (VAC) refers to the ratio of afterload (effective arterial elastance) to contractility (end-systolic elastance) as an integrated marker of cardiac performance. We sought to determine whether the echocardiographic VAC ratio, defined using the ratio of LV end-systolic volume (LVESV) to stroke volume (SV), predicted mortality in the cardiac intensive care unit (CICU). Methods and results Mayo Clinic CICU patients from 2007 and 2018 were included. Ventricular-arterial coupling ratio was calculated as the Teichholz LVESV divided by the SV calculated from LV outflow tract Doppler. The primary outcome was in-hospital mortality and the secondary outcome was all-cause 1-year mortality. A total of 4685 patients were included with a median age of 69 (58, 79) years (37.2% females), with acute coronary syndrome in 54.9% and heart failure in 49.0%. A higher VAC ratio was associated with greater severity of illness, worse echocardiographic findings, and more use of critical care therapies. A total of 329 (7%) patients died during hospitalization. Patients with a higher VAC ratio had higher in-hospital mortality overall and in each admission diagnosis subgroup. After multivariable adjustment, patients with a VAC ratio &gt;2 were at higher risk of in-hospital mortality (adjusted odds ratio 1.63, 95% confidence interval 1.17–2.28, P = 0.010). One-year mortality was higher for patients with a higher VAC ratio, especially VAC &gt;2. Conclusion Ventricular-arterial uncoupling was associated with worse outcomes in an unselected CICU cohort. The echocardiographic VAC ratio is a simple non-invasive bedside measure that can be used for risk prediction in the CICU.