Clinical and prognostic impact of chronotropic incompetence in patients with hypertrophic cardiomyopathy

Published: 17 September 2019| Version 1 | DOI: 10.17632/jzrkggb8mw.1
Damiano Magrì, piergiuseppe agostoni, Gianfranco Sinagra, Federica Re, Michele Correale, Giuseppe Limongelli, Caterina Santolamazza, Elisabetta Zachara, Matteo Casenghi, Giuseppe Pacileo, Fabio Valente, Marco Morosin, Beatrice Musumeci, Erika Pagannone, Antonello Maruotti, Massimo Volpe, Camillo Autore


BACKGROUND: A blunted heart rate (HR) response is associated with an impaired peak oxygen uptake (pVO2), a powerful outcome predictor in hypertrophic cardiomyopathy (HCM). The present multicenter study sought to determine the prognostic role for exercise-induced HR response in HCM. METHODS: A total of 681 consecutive HCM outpatients on optimized treatment were recruited. The heart failure (HF) end-point was death due to HF, cardiac transplantation, NYHA III-IV class progression, HF worsening leading to hospitalization and severe functional deterioration leading to septal reduction. The sudden cardiac death (SCD) end-point included SCD, aborted SCD and appropriate implantable cardioverter defibrillator discharges. RESULTS: During a median follow-up of 4.2 years (25-75th centile: 3.9-5.2), 81 patients reached the HF and 23 the SCD end-point. Covariates with independent effects on the HF end-point were left atrial diameter, left ventricular ejection fraction, maximal left ventricular outflow tract gradient and exercise cardiac power (ECP = pVO2∗systolic blood pressure) (C-Index = 0.807) whereas the HCM Risk-SCD score and the ECP remained associated with the SCD end-point (C-Index = 0.674). When the VO2-derived variables were not pursued, peak HR (pHR) re-entered in the multivariate HF model (C-Index = 0.777) and, marginally, in the SCD model (C-index = 0.656). A pHR = 70% of the maximum predicted resulted as the best cut-off value in predicting the HF-related events. CONCLUSIONS: The cardiopulmonary exercise test is pivotal in the HCM management, however the pHR remains a meaningful alternative parameter. A pHR < 70% identified a HCM population at high risk of HF-related events, thus calling for a reappraisal of the chronotropic incompetence threshold in HCM.



Prognosis, Heart Rate, Hypertrophic Cardiomyopathy