Search

Objectives: This study sought to identify predictors of major clinically important atrial fibrillation endpoints in hypertrophic cardiomyopathy., Background: Atrial fibrillation (AF) is a common morbidity associated with hypertrophic cardiomyopathy (HCM). The HCMR (Hypertrophic Cardiomyopathy Registry) trial is a prospective natural history study of 2,755 patients with HCM with comprehensive phenotyping., Methods: All patients received yearly telephone follow-up. Major AF endpoints were defined as requiring electrical cardioversion, catheter ablation, hospitalization for >24 h, or clinical decisions to accept permanent AF. Penalized regression via elastic-net methodology identified the most important predictors of major AF endpoints from 46 variables. This was applied to 10 datasets, and the variables were ranked. Predictors that appeared in all 10 sets were then used in a Cox model for competing risks and analyzed as time to first event., Results: Data from 2,631 (95.5%) patients were available for analysis after exclusions. A total of 127 major AF endpoints events occurred in 96 patients over 33.3 ± 12.4 months. In the final model, age, body mass index (BMI), left atrial (LA) volume index, LA contractile percent (active contraction), moderate or severe mitral regurgitation (MR), and history of arrhythmia the most important. BMI, LA volume index, and LA contractile percent were age-dependent. Obesity was a stronger risk factor in younger patients. Increased LA volume, reduced LA contractile percent, and moderate or severe MR put middle-aged and older adult patients at increased risk., Conclusions: The major predictors of major AF endpoints in HCM include older age, high BMI, moderate or severe MR, history of arrhythmia, increased LA volume, and reduced LA contractile percent. Prospective testing of a risk score based on these parameters may be warranted., Competing Interests: Funding Support and Author Disclosures This work was supported by the National Institutes of Health, the National Heart, Lung, and Blood Institute (U01HL117006-01A1) and the Oxford NIHR Biomedical Research Centre. Dr. Kramer has received research grants from MyoKardia and Cytokinetics; and has been consultant for MyoKardia and Cytokinetics. Dr. DiMarco has been a consultant to Novartis, Galmed, and Celgene. Dr. Ho has been consultant for and has received research support from MyoKardia. Dr. Kwong has received research support from Siemens Healthineers, Bayer AG, and Myokardia. Dr. Maron has received consulting and research support from iRhythm; and has been a consultant for Celltrion and Cytokinetics. Dr. Friedrich has been a board member, shareholder, and consultant of Circle Cardiovascular Imaging Inc. Dr. Schulz-Menger has been a consultant for Bayer; has received research grants from Bayer, Siemens Healthineers, and Circle Cardiovascular Imaging. Dr. Piechnik holds U.S. patent 9,285,446 B2: “Systems and methods for shortened look locker inversion recovery (Sh-MOLLI) cardiac gated mapping of T1.” Dr. Jacoby has been consultant for and has received a research grant from MyoKardia. Dr. White holds shares in Cohesic; and has received a research grant from Siemens Healthineers. Dr. Chiribiri has received research grants from Philips Healthcare and Siemens Healthineers. Dr. Helms has received research support from MyoKardia. Dr. Bradlow has received honoraria from Daichi-Sankyo. Dr. Salerno has received research support from Siemens Healthineers and Heartflow. Dr. Dawson has received research grant from Philips Healthcare. Dr. Nagueh has been a consultant for MyoKardia. Dr. Casadei has received research support from Roche Diagnostics and iRhythm. Dr. Watkins has been a consultant for Cytokinetics. Dr. Neubauer has received research grants from Boehringer Ingelheim and Cytokinetics. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The HCMR (Hypertrophic Cardiomyopathy Registry) is a National Heart, Lung, and Blood Institute-funded, prospective registry of 2,755 patients with hypertrophic cardiomyopathy (HCM) recruited from 44 sites in 6 countries., Objectives: The authors sought to improve risk prediction in HCM by incorporating cardiac magnetic resonance (CMR), genetic, and biomarker data., Methods: Demographic and echocardiographic data were collected. Patients underwent CMR including cine imaging, late gadolinium enhancement imaging (LGE) (replacement fibrosis), and T1 mapping for measurement of extracellular volume as a measure of interstitial fibrosis. Blood was drawn for the biomarkers N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (cTnT), and genetic analysis., Results: A total of 2,755 patients were studied. Mean age was 49 ± 11 years, 71% were male, and 17% non-white. Mean ESC (European Society of Cardiology) risk score was 2.48 ± 0.56. Eighteen percent had a resting left ventricular outflow tract (LVOT) gradient ≥30 mm Hg. Thirty-six percent had a sarcomere mutation identified, and 50% had any LGE. Sarcomere mutation-positive patients were more likely to have reverse septal curvature morphology, LGE, and no significant resting LVOT obstruction. Those that were sarcomere mutation negative were more likely to have isolated basal septal hypertrophy, less LGE, and more LVOT obstruction. Interstitial fibrosis was present in segments both with and without LGE. Serum NT-proBNP and cTnT levels correlated with increasing LGE and extracellular volume in a graded fashion., Conclusions: The HCMR population has characteristics of low-risk HCM. Ninety-three percent had no or only mild functional limitation. Baseline data separated patients broadly into 2 categories. One group was sarcomere mutation positive and more likely had reverse septal curvature morphology, more fibrosis, but less resting obstruction, whereas the other was sarcomere mutation negative and more likely had isolated basal septal hypertrophy with obstruction, but less fibrosis. Further follow-up will allow better understanding of these subgroups and development of an improved risk prediction model incorporating all these markers., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)