Prognostic utility of longitudinal quantification of PET myocardial blood flow early post heart transplantation.

BACKGROUND: Myocardial blood flow (MBF) quantification by Rubidium-82 positron emission tomography (PET) has shown promise for cardiac allograft vasculopathy (CAV) surveillance and risk stratification post heart transplantation. The objective was to determine the prognostic value of serial PET performed early post transplantation. METHODS AND RESULT: Heart transplant (HT) recipients at the University of Ottawa Heart Institute with 2 PET examinations (PET1 = baseline, PET2 = follow-up) within 6 years of transplant were included in the study. Evaluation of PET flow quantification included stress MBF, coronary vascular resistance (CVR), and myocardial flow reserve (MFR). The primary composite outcome was all-cause death, re-transplant, myocardial infarction, revascularization, allograft dysfunction, cardiac allograft vasculopathy (CAV), or heart failure hospitalization. A total of 121 patients were evaluated (79% male, mean age 56 ± 11 years) with consecutive scans performed at mean 1.4 ± 0.7 and 2.6 ± 1.0 years post HT for PET1 and PET2, respectively. Over a mean follow-up of 3.0 (IQR 1.8, 4.6) years, 26 (22%) patients developed the primary outcome: 1 death, 11 new or progressive angiographic CAV, 2 percutaneous coronary interventions, 12 allograft dysfunction. Unadjusted Cox analysis showed a significant reduction in event-free survival in patients with PET1 stress MBF < 2.1 (HR: 2.43, 95% CI 1.11-5.29 P = 0.047) and persistent abnormal PET1 to PET2 CVR > 76 (HR: 2.19, 95% CI 0.87-5.51 P = 0.045). There was no association between MFR and outcomes. CONCLUSION: Low-stress MBF and persistent increased CVR on serial PET imaging early post HT are associated with adverse cardiovascular outcomes. Early post-transplant and longitudinal assessment by PET may identify at-risk patients for increased surveillance post HT.

The effect of antiplatelet therapy on survival and cardiac allograft vasculopathy following heart transplantation: A systematic review and meta-analysis.

Cardiac allograft vasculopathy (CAV) is mediated by endothelial inflammation, platelet activation and thrombosis. Antiplatelet therapy may prevent the development of CAV. This systematic review and meta-analysis summarizes and appraises the evidence on the effect of antiplatelet therapy after heart transplantation (HT). CENTRAL(Ovid), MEDLINE(Ovid), Embase(Ovid) were searched from inception until April 30, 2020. Outcomes included CAV, all-cause mortality, and CAV-related mortality. Data were pooled using random-effects models. Seven observational studies including 2023 patients, mean age 52 years, 22% female, 47% with ischemic cardiomyopathy followed over a mean 7.1 years proved eligible. All studies compared acetylsalicylic acid (ASA) to no treatment and were at serious risk of bias. Data from 1911 patients in 6 studies were pooled in the meta-analyses. The evidence is very uncertain about the effect of ASA on all-cause or CAV-related mortality. ASA may reduce the development of CAV (RR 0.75, 95% CI: 0.44-1.29) based on very low certainty evidence. Two studies that conducted propensity-weighted analyses showed further reduction in CAV with ASA (HR 0.31, 95% CI: 0.13-0.74). In conclusion, there is limited evidence that ASA may reduce the development of CAV. Definitive resolution of the impact of antiplatelet therapy on CAV and mortality will require randomized clinical trials.

Validation of multiparametric rubidium-82 PET myocardial blood flow quantification for cardiac allograft vasculopathy surveillance.

BACKGROUND: We previously demonstrated high diagnostic accuracy of Rubidium-82 positron emission tomography (PET) myocardial blood flow (MBF) quantification for CAV. The purpose of this study was to validate multiparametric PET detection of CAV by combined rate-pressure-product-corrected myocardial flow reserve (cMFR), stress MBF, and coronary vascular resistance (CVR) assessment. METHODS AND RESULTS: Diagnostic CAV cut-offs of cMFR < 2.9, stress MBF < 2.3, CVR > 55 determined in a previous study (derivation) were assessed in heart transplant recipients referred for coronary angiography and intravascular ultrasound (IVUS) (validation). CAV was defined as International Society of Heart and Lung Transplantation CAV1-3 on angiography; and maximal intimal thickness ≥ 0.5 mm on IVUS. Eighty patients (derivation n = 40, validation n = 40) were included: 80% male, mean age 54±14 years, 4.5±5.6 years post transplant. The prevalence of CAV was 44% on angiography and 78% on IVUS. Combined PET cMFR < 2.9, stress MBF < 2.3, CVR > 55 CAV assessment yielded high 88% (specificity 75%) and 83% (specificity 40%) sensitivity for ≥ 1 abnormal parameter and high 88% (sensitivity 59%) and 90% (sensitivity 43%) specificity for 3 abnormal parameters, in the derivation and validation cohorts, respectively. CONCLUSION: We validate the diagnostic accuracy of multiparametric PET flow quantification by cMFR, stress MBF, and CVR for CAV.

Cardiac allograft vasculopathy: Insights on pathogenesis and therapy.

Cardiac allograft vasculopathy (CAV) is a unique accelerated form of coronary vascular disease affecting heart transplant recipients. This complication is a significant contributor to medium- to long-term post-transplant morbidity and mortality. There is a high prevalence of CAV with approximately one in three patients developing CAV by 5 years post-transplant. Morphologically, CAV is characterized by concentric coronary intimal hyperplasia in both the epicardial arteries and intramural microvasculature. Although several immune and non-immune factors have been identified, their precise pathogenic mechanisms, interactions, and relative importance in the development of CAV are not well defined. The advent of improved imaging surveillance modalities has resulted in earlier detection during the disease process. However, overall management of CAV remains challenging due to paucity of treatment. This review aims to discuss key concepts on the pathogenesis of CAV and current management strategies, focusing on the use of mammalian target of rapamycin inhibitors.

Biomarker discovery in cardiac allograft vasculopathy using targeted aptamer proteomics.

Cardiac allograft vasculopathy (CAV) limits long-term survival after heart transplantation. Non-invasive evaluation is challenging, and currently, there is no validated biomarker for CAV diagnosis or prognostication. To identify potential candidate CAV biomarkers, we utilized the Slow Off-rate Modified Aptamer (SOMAscan) assay, which evaluates over 1000 serum proteins, including many relevant to biological pathways in CAV. We evaluated three heart transplant patient groups according to angiographic ISHLT CAV grade: CAV1-2 (mild-moderate CAV), CAV3 (severe CAV), and CAV0 (normal control). SOMAscan assays were performed and proteins quantitated. Comparisons of proteins between study groups were performed using one-way ANOVA (false discovery rate q-value < 0.10). Thirty-one patients (12 mild-moderate CAV, 9 severe CAV, 10 controls) were included: 81% male, median age 57 years and median 1.1 years post-transplant. Compared to controls, patients with mild-moderate CAV had similar characteristics, while patients with severe CAV had longer time from transplant and increased allosensitization. Statistical/bioinformatics analysis identified 14 novel biomarkers for CAV, including 4 specific for mild-moderate CAV. These proteins demonstrated important actions including apoptosis, inflammation, and platelet/coagulation activation. Upon preliminary receiver operating characteristics curve analysis, our protein biomarkers showed moderate-to-high discriminative ability for CAV (area under curve: 0.72 to 0.94). These candidate biomarkers are being validated in prospective studies.

Utility of the INTERMACS profile at the time of assessment for heart transplant.

The Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS) profiles are associated with mortality in heart failure patients undergoing ventricular assist device (VAD) implantation and heart transplantation (HTx). We assessed the prognostic value of the INTERMACS profile at the time of assessment for HTx or durable VAD implantation as bridge to candidacy (BTC). A total of 503 consecutive patients considered for HTx or VAD between 2006 and 2016 were included. The associations between INTERMACS profile and (a) waitlist mortality or delisting, (b) probability of HTx, and (c) overall mortality or delisting were evaluated using multivariable analysis. Median follow-up time was 2.9 years (IQR: 0.9-5.5) during which 184 received VAD, 347 received HTx, and 73 died (27 waitlist, 46 post-transplant). INTERMACS I-II profile was associated with higher waitlist mortality or delisting (HR: 3.83, 95% CI: 1.22-12.03), and this risk was reversed by VAD implantation (HR: 0.12, 95% CI: 0.03-0.50). INTERMACS III-IV profile was associated with a higher probability of HTx (HR: 1.82, 95% CI: 1.37-2.40). INTERMACS profile was not associated with the composite outcome of overall mortality or delisting. These results emphasize the prognostic utility of INTERMACS at time of decision for advanced therapies and its potential value in selecting patients for different interventions.

When to intervene for donor-specific antibody after heart transplantation.

PURPOSE OF REVIEW: Posttransplant donor-specific human leukocyte antigen (HLA) antibodies (DSA) represent a complex area in heart transplantation with nonstandardized practice and paucity of clinical data to guide optimal management. RECENT FINDINGS: De novo DSA after heart transplantation is common and associated with rejection, cardiac allograft vasculopathy, allograft failure, and mortality. Advances in methods for HLA antibody detection have enabled identification of DSA with high precision and sensitivity. The detection of HLA antibodies must, however, be interpreted within appropriate laboratory and clinical contexts; it remains unclear which DSA are associated with greatest clinical risk. Increased antibody and clinical surveillance as well as optimization of maintenance immunosuppression are required for all patients with DSA. Antibody-directed therapies are reserved for patients with allograft dysfunction or rejection. Treatment of DSA may also be considered in asymptomatic high-risk patients including those in whom DSA arise de novo posttransplant, is persistent, high titer, or complement activating. The impact of DSA reduction and removal on long-term clinical outcomes remains unknown. SUMMARY: Despite improvements in DSA detection, identification, and characterization, best therapeutic strategies are unclear. Prospective multicenter studies are needed to develop effective standardized approaches for DSA management in heart transplantation.

Clinical Outcomes of Patients Treated With Pulmonary Vasodilators Early and in High Dose After Left Ventricular Assist Device Implantation.

Right ventricular failure (RVF) is common after left ventricular assist device (LVAD) implantation and a major determinant of adverse outcomes. Optimal perioperative right ventricular (RV) management is not well defined. We evaluated the use of pulmonary vasodilator therapy during LVAD implantation. We performed a retrospective analysis of continuous-flow LVAD implants and pulmonary vasodilator use at our institution between September 2004 and June 2013. Preoperative RVF risk was assessed using recognized variables. Sixty-five patients (80% men, 50 ± 14 years) were included: 52% HeartWare ventricular assist device (HVAD), 11% HeartMate II (HMII), 17% VentrAssist, 20% Jarvik. Predicted RVF risk was comparable with contemporary LVAD populations: 8% ventilated, 14% mechanical support, 86% inotropes, 25% BUN >39 mg/dL, 23% bilirubin ≥2 mg/dL, 31% RV : LV (left ventricular) diameter ≥0.75, 27% RA : PCWP (right atrium : pulmonary capillary wedge pressure) >0.63, 36% RV stroke work index <6 gm-m/m(2)/beat. The majority (91%) received pulmonary vasodilators early and in high dose: 72% nitric oxide, 77% sildenafil (max 200 ± 79 mg/day), 66% iloprost (max 126 ± 37 µg/day). Median hospital stay was 26 (21) days. No patient required RV mechanical support. Of six (9%) patients meeting RVF criteria based on prolonged need for inotropes, four were transplanted, one is alive with an LVAD at 3 years, and one died on day 35 of intracranial hemorrhage. Two-year survival was 77% (92% for HMII/HVAD): transplanted 54%, alive with LVAD 21%, recovery/explanted 2%. A low incidence of RVF and excellent outcomes were observed for patients treated early during LVAD implantation with combination, high-dose pulmonary vasodilators. The results warrant further investigation in a randomized controlled study.

Successful Heart Transplant after Ten Hours Out-of-body Time using the TransMedics Organ Care System.

OBJECTIVE: We report the successful transplantation of a heart following an out-of-body time of 611 minutes into a recipient with dilated cardiomyopathy and left ventricular assist device implant. PATIENTS: Our patient was urgently waiting for a cardiac transplant whilst receiving LVAD support. Recurrent VF and repeated AICD shocks necessitated this action. RESULTS: Although requiring ECMO and inotropic support in the first 17 hours post-transplant, the patient was discharged from hospital on day 15 post-transplant with normal cardiac function. CONCLUSION: We report some of the salient points of the process and discuss the utility of this technology to an Australian transplant unit.

Enhancing the Prediction of Cardiac Allograft Vasculopathy Using Intravascular Ultrasound and Machine Learning: A Proof of Concept.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is the leading cause of late graft dysfunction in heart transplantation. Building on previous unsupervised learning models, we sought to identify CAV clusters using serial maximal intimal thickness and baseline clinical risk factors to predict the development of early CAV. METHODS: This is a single-center retrospective study including adult heart transplantation recipients. A latent class mixed-effects model was used to identify patient clusters with similar trajectories of maximal intimal thickness posttransplant and pretransplant covariates associated with each cluster. RESULTS: Among 186 heart transplantation recipients, we identified 4 patient phenotypes: very low, low, moderate, and high risk. The 5-year risk (95% CI) of the International Society for Heart and Lung Transplantation-defined CAV in the high, moderate, low, and very low risk groups was 49.1% (35.2%-68.5%), 23.4% (13.3%-41.2%), 5.0% (1.3%-19.6%), and 0%, respectively. Only patients in the moderate to high risk cluster developed the International Society for Heart and Lung Transplantation CAV 2-3 at 5 years (P=0.02). Of the 4 groups, the low risk group had significantly younger female recipients, shorter ischemic time, and younger female donors compared with the high risk group. CONCLUSIONS: We identified 4 clusters characterized by distinct maximal intimal thickness trajectories. These clusters were shown to discriminate against the development of angiographic CAV. This approach allows for the personalization of surveillance and CAV-directed treatment before the development of angiographically apparent disease.

Heart failure related cardiogenic shock: An ISHLT consensus conference content summary.

In recent years, there have been significant advancements in the understanding, risk-stratification, and treatment of cardiogenic shock (CS). Despite improved pharmacologic and device-based therapies for CS, short-term mortality remains as high as 50%. Most recent efforts in research have focused on CS related to acute myocardial infarction, even though heart failure related CS (HF-CS) accounts for >50% of CS cases. There is a paucity of high-quality evidence to support standardized clinical practices in approach to HF-CS. In addition, there is an unmet need to identify disease-specific diagnostic and risk-stratification strategies upon admission, which might ultimately guide the choice of therapies, and thereby improve outcomes and optimize resource allocation. The heterogeneity in defining CS, patient phenotypes, treatment goals and therapies has resulted in difficulty comparing published reports and standardized treatment algorithms. An International Society for Heart and Lung Transplantation (ISHLT) consensus conference was organized to better define, diagnose, and manage HF-CS. There were 54 participants (advanced heart failure and interventional cardiologists, cardiothoracic surgeons, critical care cardiologists, intensivists, pharmacists, and allied health professionals), with vast clinical and published experience in CS, representing 42 centers worldwide. State-of-the-art HF-CS presentations occurred with subsequent breakout sessions planned in an attempt to reach consensus on various issues, including but not limited to models of CS care delivery, patient presentations in HF-CS, and strategies in HF-CS management. This consensus report summarizes the contemporary literature review on HF-CS presented in the first half of the conference (part 1), while the accompanying document (part 2) covers the breakout sessions where the previously agreed upon clinical issues were discussed with an aim to get to a consensus.

Consensus statements from the International Society for Heart and Lung Transplantation consensus conference: Heart failure-related cardiogenic shock.

The last decade has brought tremendous interest in the problem of cardiogenic shock. However, the mortality rate of this syndrome approaches 50%, and other than prompt myocardial revascularization, there have been no treatments proven to improve the survival of these patients. The bulk of studies have been in patients with acute myocardial infarction, and there is little evidence to guide the clinician in those patients with heart failure cardiogenic shock (HF-CS). An International Society for Heart and Lung Transplant consensus conference was organized to better define, diagnose, and manage HF-CS. There were 54 participants (advanced heart failure and interventional cardiologists, cardiothoracic surgeons, critical care cardiologists, intensivists, pharmacists, and allied health professionals) with vast clinical and published experience in CS, representing 42 centers worldwide. This consensus report summarizes the results of a premeeting survey answered by participants and the breakout sessions where predefined clinical issues were discussed to achieve consensus in the absence of robust data. Key issues discussed include systems for CS management, including the "hub-and-spoke" model vs a tier-based network, minimum levels of data to communicate when considering transfer, disciplines that should be involved in a "shock team," goals for mechanical circulatory support device selection, and optimal flow on such devices. Overall, the document provides expert consensus on some important issues facing practitioners managing HF-CS. It is hoped that this will clarify areas where consensus has been reached and stimulate future research and registries to provide insight regarding other crucial knowledge gaps.

Factors Impacting Physician Prognostic Accuracy in Heart Failure Patients With Reduced Left Ventricular Ejection Fraction.

BACKGROUND: A recent study showed that the accuracy of heart failure (HF) cardiologists and family doctors to predict mortality in outpatients with HF proved suboptimal, performing less well than models. OBJECTIVES: The authors sought to evaluate patient and physician factors associated with physician accuracy. METHODS: The authors included outpatients with HF from 11 HF clinics. Family doctors and HF cardiologists estimated patient 1-year mortality. They calculated predicted mortality using the Seattle HF Model and followed patients for 1 year to record mortality (or urgent heart transplant or ventricular assist device implant as mortality-equivalent events). Using multivariable logistic regression, the authors evaluated associations among physician experience and confidence in estimates, duration of patient-physician relationship, patient-physician sex concordance, patient race, and predicted risk, with concordant results between physician and model predictions. RESULTS: Among 1,643 patients, 1-year event rate was 10% (95% CI: 8%-12%). One-half of the estimates showed discrepant results between model and physician predictions, mainly owing to physician risk overestimation. Discrepancies were more frequent with increasing patient risk from 38% in low-risk to ∼75% in high-risk patients. When making predictions on male patients, female HF cardiologists were 26% more likely to have discrepant predictions (OR: 0.74; 95% CI: 0.58-0.94). HF cardiologist estimates in Black patients were 33% more likely to be discrepant (OR: 0.67; 95% CI: 0.45-0.99). Low confidence in predictions was associated with discrepancy. Analyses restricted to high-confidence estimates showed inferior calibration to the model, with risk overestimation across risk groups. CONCLUSIONS: Discrepant physician and model predictions were more frequent in cases with perceived increased risk. Model predictions outperform physicians even when they are confident in their predictions. (Predicted Prognosis in Heart Failure [INTUITION]; NCT04009798).

Need for a Cardiogenic Shock Team Collaborative-Promoting a Team-Based Model of Care to Improve Outcomes and Identify Best Practices.

Cardiogenic shock continues to carry a high mortality rate despite contemporary care, with no breakthrough therapies shown to improve survival over the past few decades. It is a time-sensitive condition that commonly results in cardiovascular complications and multisystem organ failure, necessitating multidisciplinary expertise. Managing patients with cardiogenic shock remains challenging even in well-resourced settings, and an important subgroup of patients may require cardiac replacement therapy. As a result, the idea of leveraging the collective cognitive and procedural proficiencies of multiple providers in a collaborative, team-based approach to care (the "shock team") has been advocated by professional societies and implemented at select high-volume clinical centers. A slowly maturing evidence base has suggested that cardiogenic shock teams may improve patient outcomes. Although several registries exist that are beginning to inform care, particularly around therapeutic strategies of pharmacologic and mechanical circulatory support, none of these are currently focused on the shock team approach, multispecialty partnership, education, or process improvement. We propose the creation of a Cardiogenic Shock Team Collaborative-akin to the successful Pulmonary Embolism Response Team Consortium-with a goal to promote sharing of care protocols, education of stakeholders, and discovery of how process and performance may influence patient outcomes, quality, resource consumption, and costs of care.

The COVID-19 Pandemic and Adult Cardiac Transplantation: Impact, Interventions, and Implications.

In this review, we provide a comprehensive overview of the impact of the COVID-19 pandemic on adult heart transplantation. We highlight the decline in the number of adult transplantations performed throughout the pandemic as a consequence of restrictions imposed on individual programs and hospitals. There were challenges to maintaining cardiac transplant activity at multiple levels, including organ donation in intensive care units, logistical difficulties with organ procurement, and rapidly changing resource considerations at health system and jurisdictional levels. We also review the impact of COVID-19 on cardiac transplant recipients. Despite the high rates of morbidity and mortality observed during the initial phases of the pandemic among heart transplant patients infected with COVID-19, the availability of effective vaccines, pre-exposure prophylaxis, and specific antiviral therapies have drastically improved outcomes over time. Vaccines have proven to be safe and effective in reducing infections and illness severity, but specific considerations in the immunocompromised solid organ transplant population apply, including the need for additional booster doses to achieve sufficient immunisation. We further outline the strong rationale for vaccination before transplantation wherever possible. Finally, the COVID-19 response created a number of barriers to safe and efficient post-transplantation care. Given the need for frequent evaluation and monitoring, especially in the first several months after cardiac transplantation, the pandemic provided the impetus to improve virtual care delivery and explore noninvasive rejection surveillance through gene expression profiling. We hope that lessons learned will allow us to prepare and pivot effectively during future pandemics and health care emergencies.

Fibrotic Plaque and Microvascular Dysfunction Predict Early Cardiac Allograft Vasculopathy Progression After Heart Transplantation: The Early Post Transplant Cardiac Allograft Vasculopathy Study.

BACKGROUND: Early cardiac allograft vasculopathy (CAV) prognostication is needed to improve long-term outcomes after heart transplantation. We characterized first year posttransplant coronary anatomic-physiologic alterations to determine predictors of early CAV progression. METHODS: Heart transplant recipients at 2 institutions (enrolled January 2018 to March 2021) underwent prospective evaluation 3 and 12-month posttransplant with angiography and left anterior descending artery intravascular ultrasound, optical coherence tomography, fractional flow reserve, coronary flow reserve, and index of microcirculatory resistance measurements. CAV progression was assessed by intravascular ultrasound change in percentage intimal volume from baseline to 12-month follow-up. RESULTS: Eighty-two patients (mean age, 51 years; 60% men) completed evaluation at mean 13.8 and 56.3 weeks posttransplant. Donor atherosclerosis (baseline intravascular ultrasound maximal intimal thickness, ≥0.5 mm) was evident in 50%. De novo (follow-up maximal intimal thickness, ≥0.5 mm) and rapidly progressive CAV (maximal intimal thickness, ≥0.5-mm increase from baseline) developed in 24% and 13%, respectively. On optical coherence tomography, baseline to follow-up median intimal volume increased 42% (0.58 mm3/mm), percentage intimal volume increased 44% (4.6%), vessel volume decreased 4% (-0.50 mm3/mm) and lumen volume decreased 9% (-1.02 mm3/mm); P<0.05 for all. Fibrotic plaque was the predominant morphology: baseline, 29% and follow-up, 50%. Coronary physiology was abnormal in 41% at baseline and 45% at follow-up, with 1 in 5 patients having microvascular dysfunction (index of microcirculatory resistance, ≥25). On multivariable linear regression analysis, recipient male sex, fibrotic plaque, and index of microcirculatory resistance were independent predictors of coronary disease progression. CONCLUSIONS: Fibrotic plaque on optical coherence tomography and index of microcirculatory resistance early posttransplant predict CAV progression in the first year of transplantation. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03217786.

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy.

BACKGROUND: Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant. OBJECTIVES: The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification. METHODS: Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination. Epicardial CAV was assessed by intravascular ultrasound percent intimal volume (PIV) and microvascular CAV by endomyocardial biopsy. RESULTS: A total of 136 PET studies from 74 patients were analyzed. At 12 months, median PIV increased 5.6% (95% CI: 3.6%-7.1%) with no change in microvascular CAV incidence (baseline: 31% vs follow-up: 38%; P = 0.406) and persistent microvascular disease in 13% of patients. Median capillary density increased 30 capillaries/mm2 (95% CI: -6 to 79 capillaries/mm2). PET myocardial flow reserve (2.5 ± 0.7 vs 2.9 ± 0.8; P = 0.001) and stress MBF (2.7 ± 0.6 vs 2.9 ± 0.6; P = 0.008) increased, and coronary vascular resistance (CVR) (49 ± 13 vs 47 ± 11; P = 0.214) was unchanged. At 12 months, PET and PIV had modest correlation (stress MBF: r = -0.35; CVR: r = 0.33), with lower stress MBF and higher CVR across increasing PIV tertiles (all P < 0.05). Receiver-operating characteristic curves for CAV defined by upper-tertile PIV showed areas under the curve of 0.74 for stress MBF and 0.73 for CVR. CONCLUSIONS: The 1-year post-transplant PET MBF is associated with epicardial CAV, supporting potential use for early noninvasive CAV assessment. (Early Post Transplant Cardiac Allograft Vasculopahty [ECAV]; NCT03217786).

Predicting 1-Year Mortality in Outpatients With Heart Failure With Reduced Left Ventricular Ejection Fraction: Do Empiric Models Outperform Physician Intuitive Estimates? A Multicenter Cohort Study.

BACKGROUND: Many studies have demonstrated that physicians often err in estimating patient prognosis. No studies have directly compared physician to model predictive performance in heart failure (HF). We aimed to compare the accuracy of physician versus model predictions of 1-year mortality. METHODS: This multicenter prospective cohort study on 11 HF clinics in 5 provinces in Canada included consecutive consented outpatients with HF with reduced left ventricular ejection fraction (<40%). By collecting clinical data, we calculated predicted 1-year mortality using the Seattle HF Model (SHFM), the Meta-Analysis Global Group in Chronic HF score, and the HF Meta-Score. HF cardiologists and family doctors, blinded to model predictions, estimated patient 1-year mortality. During 1-year follow-up, we recorded the composite end point of mortality, urgent ventricular assist device implant, or heart transplant. We compared physicians and model discrimination (C statistic), calibration (observed versus predicted event rate), and risk reclassification. RESULTS: The study included 1643 patients with ambulatory HF with a mean age of 65 years, 24% female, and mean left ventricular ejection fraction of 28%. Over 1-year follow-up, 9% had an event. The SHFM had the best discrimination (SHFM C statistic 0.76; HF Meta-Score 0.73; Meta-Analysis Global Group in Chronic Heart Failure 0.70) and calibration. Physicians' discrimination differed little (0.75 for HF cardiologists and 0.73 for family doctors) but both physician groups substantially overestimated risk by >10% in both low- and high-risk patients (poor calibration). In risk reclassification analysis, among patients without events, the SHFM better classified 51% in comparison to HF cardiologists and 43% in comparison to family doctors. In patients with events, the SHFM erroneously assigned lower risk to 44% in comparison to HF cardiologists and 34% in comparison to family doctors. CONCLUSIONS: Family doctors and HF cardiologists showed adequate risk discrimination, with however substantial overestimation of absolute risk. Predictive models showed higher accuracy. Incorporating models in family and HF cardiology practices may improve patient care and resource use in HF with reduced left ventricular ejection fraction. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04009798.

Case Report: Severe Peripartum Cardiac Disease in Myotonic Dystrophy Type 1.

Background: Myotonic dystrophy type 1 (DM1) is a hereditary muscular dystrophy affecting ∼2.1-14.3/100,000 adults. Cardiac manifestations of DM1 include conduction disorders and rarely cardiomyopathies. DM1 increases the risk of obstetric complications, however, little is known about the relationship between pregnancy and cardiomyopathy in DM1 due to disease rarity. Case: A 23-year-old with DM1 developed cardiomyopathy during pregnancy. Despite initial medical stabilization, she subsequently developed multiple spontaneous coronary artery dissections postpartum, worsening cardiomyopathy and multiorgan failure. She died 5 months postpartum. Conclusion: Though cardiomyopathy and arterial dissection are both known complications of pregnancy, this case suggests individuals with myotonic dystrophy type 1 may be at heightened risk for cardiac disease during the peripartum period. Physicians caring for women with suspected or proven DM1 should offer counseling and be alerted to the risk of cardiac complications with pregnancy and in the peripartum period. Pregnant and peripartum women with DM1 are likely to benefit from more frequent assessments of cardiac function including echocardiograms and early institution of heart failure management protocols when symptoms of cardiomyopathy present.