Background: A blunted heart rate (HR) response is associated with an impaired peak oxygen uptake (pVO(2)), 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-pointwas 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=pVO(2)*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. (c) 2018 Elsevier B.V. All rights reserved.
Clinical and prognostic impact of chronotropic incompetence in patients with hypertrophic cardiomyopathy
Limongelli, Giuseppe;
2018
Abstract
Background: A blunted heart rate (HR) response is associated with an impaired peak oxygen uptake (pVO(2)), 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-pointwas 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=pVO(2)*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. (c) 2018 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
