Kanaji, Yoshihisa

Background: Cardiac allograft vasculopathy (CAV) is one of the leading causes of graft failure and death after heart transplantation (HTx). Conventionally, CAV is characterized by concentric intimal thickening, however the long-term progression patterns of plaque morphology are not yet well understood. Research Question: This study aimed to assess the plaque morphology, including histology and eccentricity, in a temporal manner post-HTx using virtual histology intravascular ultrasonography (VH-IVUS). Methods: We included 50 patients who underwent serial VH-IVUS assessment at three assessment points (A1:0-1 year, A2:3-5 years, A3:7-10 years) after HTx. Differences in VH-IVUS findings between timepoints A1 to A2 (early period) and A2 to A3 (late period) were investigated. Plaque volume index was defined as (plaque volume/vessel volume) × 100%. Eccentricity index (EI) was defined as (maximum intimal thickness – minimum intimal thickness)/maximum intimal thickness and was evaluated in 39 patients with significant plaque (maximal intimal thickness >0.50 mm at the A3) at each timepoint. The serial changes of EI and relationship between EI and other VH-IVUS findings were investigated. Results: Of 50 patients, mean age was 51±13 years, 36 (72%) were males. In both early and late periods, the plaque volume (PV) index showed a significant increase, however, the rate of progression was significantly slower in late period. (5.8% [0.9, 13.2] vs 2.4% [-0.2, 7.4], p=0.015). The EI showed a trend of decrease in the early period, compared to increases in the late period (-0.040 [-0.103, 0.004] vs 0.003 [-0.030, 0.052], p=0.036). Patients with EI change in late period higher than median value had significantly lower proportion of fibrous plaque (70.8% [67.2, 75.1] vs 62.7 [55.5, 66.9], p=0.002) and higher dense calcium (1.1% [0.9, 1.9], 4.5% [1.8, 6.9], p=0.022) at A3. Conclusion: In heart transplant patients, coronary artery plaque progression in the late period showed more eccentric progression with lower fibrous plaque composition, a pattern commonly observed in typical and conventional coronary atherosclerosis. These findings may provide a novel mechanism and therapeutic insight into the temporal patterns in CAV progression during long term follow up.

Background Myocardial bridging (MB) is accompanied by the dynamic extravascular compression of epicardial coronary arteries, leading to intracoronary hemodynamic disturbance with abnormal coronary flow profiles. We aimed to evaluate the prognostic implications of resistive reserve ratio (RRR), a composite measure of flow and pressure parameters that represents the vasodilatory capacity of the coronary arteries, in patients with angina with nonobstructive coronary artery disease (ANOCA) and MB, in comparison with coronary flow reserve (CFR). Methods and Results In this retrospective cohort study, we included patients with ANOCA who underwent coronary reactivity testing, where MB was identified by transient constriction in coronary artery segments between systole and diastole. Abnormal CFR and RRR were defined as <2.5 and <2.62, respectively. Major adverse cardiac events, including cardiovascular death, stroke, myocardial infarction, heart failure, and late revascularization, served as outcomes. Among 1251 patients with ANOCA, 191 (15.3%) had MB. The prevalence of abnormal CFR or RRR was not significantly different between patients with and without MB ( P =0.144 and P =0.398, respectively). Over a median follow‐up time of 6.9 years, abnormal RRR predicted major adverse cardiac events in patients with MB (hazard ratio [HR], 4.38 [95% CI, 1.71–11.21]; P =0.002) and without MB (HR, 1.91 [95% CI, 1.38–2.64]; P <0.001). Abnormal CFR predicted major adverse cardiac events in patients without MB (HR, 2.15 [95% CI, 1.54–3.00]; P <0.001), whereas it was not predictive of major adverse cardiac events in patients with MB (HR, 2.29 [95% CI, 0.93–5.65]; P =0.073). Conclusions In patients with ANOCA and MB, impaired RRR was superior to impaired CFR in distinguishing patients at a higher risk of future adverse events, suggesting that RRR may serve as a risk stratification tool in patients with MB and ANOCA.

Background Recent studies have indicated high rates of future major adverse cardiovascular events in patients with Takotsubo cardiomyopathy (TC), but there is no well‐established tool for risk stratification. This study sought to evaluate the prognostic value of several artificial intelligence‐augmented ECG (AI‐ECG) algorithms in patients with TC. Methods and Results This study examined consecutive patients in the prospective and observational Mayo Clinic Takotsubo syndrome registry. Several previously validated AI‐ECG algorithms were used for the estimation of ECG‐ age, probability of low ejection fraction, and probability of atrial fibrillation. Multivariable models were constructed to evaluate the association of AI‐ECG and other clinical characteristics with major adverse cardiac events, defined as cardiovascular death, recurrence of TC, nonfatal myocardial infarction, hospitalization for congestive heart failure, and stroke. In the final analysis, 305 patients with TC were studied over a median follow‐up of 4.8 years. Patients with future major adverse cardiac events were more likely to be older, have a history of hypertension, congestive heart failure, worse renal function, as well as high‐risk AI‐ECG findings compared with those without. Multivariable Cox proportional hazards analysis indicated that the presence of 2 or 3 high‐risk findings detected by AI‐ECG remained a significant predictor of major adverse cardiac events in patients with TC after adjustment by conventional risk factors (hazard ratio, 4.419 [95% CI, 1.833–10.66], P =0.001). Conclusions The combined use of AI‐ECG algorithms derived from a single 12‐lead ECG might detect subtle underlying patterns associated with worse outcomes in patients with TC. This approach might be beneficial for stratifying high‐risk patients with TC.

BACKGROUND: The financial burden linked to the diagnosis and treatment of patients with chest pain on the health care system is considerable. Angina and nonobstructive coronary artery disease (ANOCA) is common, associated with adverse cardiovascular events, and may lead to repeat testing or hospitalizations. Diagnostic certainty can be achieved in patients with ANOCA using coronary reactivity testing (CRT); however, its financial effect on the patient has not been studied. Our goal was to assess the effect of CRT on health care–related cost in patients with ANOCA. METHODS: Patients with ANOCA who underwent diagnostic coronary angiography (CAG) and CRT (CRT group) were matched to controls who had similar presentation but only underwent a CAG without CRT (CAG group). Standardized inflation-adjusted costs were collected and compared between the 2 groups on an annual basis for 2 years post the index date (CRT or CAG). RESULTS: Two hundred seven CRT and 207 CAG patients were included in the study with an average age of 52.3±11.5 years and 76% females. The total cost was significantly higher in the CAG group as compared with the CRT group ($37 804 [$26 933–$48 674] versus $13 679 [$9447–$17 910]; P <0.001). When costs are itemized and divided based on the Berenson-Eggers Type of Service categorization, the largest cost difference occurred in imaging (any type, including CAG; P <0.001), procedures (eg, percutaneous coronary intervention/coronary artery bypass grafting/thrombectomy) ( P =0.001), and test (eg, blood tests, EKG; P <0.001). CONCLUSIONS: In this retrospective observational study, assessment of CRT in patients with ANOCA was associated with significantly reduced annual total costs and health care utilization. Therefore, the study may support the integration of CRT into clinical practice.

Introduction: Mechanisms underlying bioprosthetic valve deterioration (BVD) are multifactorial and incompletely elucidated. Reparative circulating progenitor cells (CPCs), and conversely calcification-associated osteocalcin expressing CPCs (CPC-OCN), have been linked to native aortic valve deterioration. However, their role in BVD remains elusive. This study sought to evaluate the contribution of different subpopulations of CPCs in BVD. Methods: This prospective study enrolled 121 patients who had peripheral blood mononuclear cells (PBMC) isolated prior to bioprosthetic aortic valve replacement (surgical 104, transcatheter 17) and had an echocardiographic follow-up ≥2 years after the procedure. Using flow cytometry, fresh PBMC were analyzed for the surface markers CD34, CD133, and osteocalcin (OCN). BVD was evaluated by hemodynamic valve deterioration (HVD) using echocardiography, which was defined as an elevated mean transprosthetic gradient ≥30mmHg and/or at least moderate intraprosthetic regurgitation. Multivariable models were constructed to evaluate the association of each subpopulation of CPCs and other clinical characteristics with HVD. Results: Sixteen patients (13.2%) developed HVD during follow-up for a median of 5.9 years. Patients with HVD showed significantly lower levels of reparative CD34 + CD133 + cells and higher levels of OCN + cells than those without HVD (CD34 + CD133 + cells: 125 [80, 210] vs 270 [130, 420], P=0.002; OCN + cells: 3060 [523, 5528] vs 670 [180, 1930], P=0.005 respectively). Decreased level of CD34 + CD133 + cells was a significant predictor of HVD. Conclusions: Circulating levels of CD34 + CD133 + cells and OCN + cells were significantly associated with the subsequent occurrence of HVD in patients undergoing bioprosthetic aortic valve replacement. CPCs might play a vital role in the mechanism, risk stratification and a potential therapeutic target for patients with bioprosthetic valve deterioration.

Introduction: Recent studies have indicated high rates of future major adverse cardiovascular events in patients with Takotsubo cardiomyopathy (TTC). This study sought to evaluate the prognostic value of our institutional artificial intelligence-augmented electrocardiography (AI-ECG) algorithms in patients with TTC. Methods: This study enrolled consecutive patients in the prospective and observational Mayo Clinic Takotsubo syndrome registry. TTC was diagnosed according to the Mayo Clinic diagnostic. Our clinic’s previously developed and validated AI-ECG algorithms were used for detection of ECG-Age, probability of low ejection fraction, and probability of atrial fibrillation.Multivariable models were constructed to evaluate the association of AI-ECG and other clinical characteristics with major adverse cardiac events (MACE), defined as cardiac death, recurrence of TTC, nonfatal myocardial infarction, hospitalization for congestive heart failure, and stroke. Results: In the final analysis, 305 patients were studied over a median follow-up of 4.8 years. Patients with MACE were more likely to be older, have history of hypertension and chronic heart failure (CHF), worse renal function as well as having high-risk AI-ECG findings compared to those without. In the multivariate Cox proportional hazard analysis, the presence of 3 or 4 high-risk findings detected by AI-ECG, remained a significant predictor of MACE in the patients with TTC after adjusted by conventional risk factors (hazard ratio (HR) 2.17, 95% CI [1.33, 3.53], P=0.002; HR 2.44, 95% CI [1.38, 4.29], P=0.002, respectively). Conclusions: The combined use of developed AI-ECG algorithms derived from a single 12-lead ECG might identify ECG correlates of underlying non-transient myocardial dysfunction and detect subtle underlying patterns associated with worse outcomes in patients with TTC. This approach might be beneficial for stratifying high-risk patients with TTC.

Background Mechanisms underlying bioprosthetic valve deterioration are multifactorial and incompletely elucidated. Reparative circulating progenitor cells, and conversely calcification‐associated osteocalcin expressing circulating progenitor cells, have been linked to native aortic valve deterioration. However, their role in bioprosthetic valve deterioration remains elusive. This study sought to evaluate the contribution of different subpopulations of circulating progenitor cells in bioprosthetic valve deterioration. Methods and Results This single‐center prospective study enrolled 121 patients who had peripheral blood mononuclear cells isolated before bioprosthetic aortic valve replacement and had an echocardiographic follow‐up ≥2 years after the procedure. Using flow cytometry, fresh peripheral blood mononuclear cells were analyzed for the surface markers CD34, CD133, and osteocalcin. Bioprosthetic valve deterioration was evaluated by hemodynamic valve deterioration (HVD) using echocardiography, which was defined as an elevated mean transprosthetic gradient ≥30 mm Hg or at least moderate intraprosthetic regurgitation. Sixteen patients (13.2%) developed HVD during follow‐up for a median of 5.9 years. Patients with HVD showed significantly lower levels of reparative CD34 + CD133 + cells and higher levels of osteocalcin‐positive cells than those without HVD (CD34 + CD133 + cells: 125 [80, 210] versus 270 [130, 420], P =0.002; osteocalcin‐positive cells: 3060 [523, 5528] versus 670 [180, 1930], P =0.005 respectively). Decreased level of CD34 + CD133 + cells was a significant predictor of HVD (hazard ratio, 0.995 [95% CI, 0.990%–0.999%]). Conclusions Circulating levels of CD34 + CD133 + cells and osteocalcin‐positive cells were significantly associated with the subsequent occurrence of HVD in patients undergoing bioprosthetic aortic valve replacement. Circulating progenitor cells might play a vital role in the mechanism, risk stratification, and a potential therapeutic target for patients with bioprosthetic valve deterioration.