Abstract

HEART RATE MANIPULATION IN IDIOPATHIC DILATED CARDIOMYOPATHY: ASSESSING THE ROLE OF IVABRADINE

Author(s): Nirmal Kumar Mohanty, Dipak Narayan Lenka, Satya Narayan Routray, Chabi Satpathy, Bijaykumar Dash

BACKGROUND The prevalence of chronic heart failure (HF) in the general population has been estimated to be around 2–3%.1 Dilated cardiomyopathy (DCM) is the most common cause of HF in young adults.2 The recognition of elevated heart rate as a risk factor for cardiovascular morbidity and mortality and its association with sudden cardiac death has made lowering the heart rate in HF patients one of the most important therapeutic approaches. The aim of the study is to assess the role of ivabradine in idiopathic dilated cardiomyopathy by modulating heart rate, based on functional class, and echocardiographic parameters. MATERIALS AND METHODS In this study, a prospective, non-randomised, double arm, open label, longitudinal one, 80 patients of DCM (idiopathic) were taken into study after exercising the inclusion and exclusion criteria as per the study protocol. Subjects were selected from those attending Cardiology OPD or admitted to Cardiology ward of S.C.B. Medical College, Cuttack, Odisha during period of Aug 2016-Aug 2017. They were divided into Ivabradine group (cases/group A) and standard tt. Group (controls/group B). RESULTS The baseline data of the 40 cases and 40 controls are presented. The reasons for patients not receiving target doses of carvedilol were hypotension, asthma, chronic obstructive airway disease, and fatigue. The reasons for not achieving target doses of ACEI were development of hypotension and severe dizziness. As shown in the table the baseline HR, blood pressure, exercise tolerance, Minnesota questionnaire score, and LV systolic function were all comparable between the two groups (p >0.05) for all. CONCLUSION To conclude the addition of Ivabradine in patients with dilated (idiopathic) cardiomyopathy resulted in significant improvement in functional capacity, Minnesota questionnaire score and LV dimension. The lack of improvement in NYHA class and EF(%) may be due to limitations of the study like small sample volume and short duration of follow up. However, it should be remembered that all patients must receive the maximally tolerated doses of beta blockers, ACEI/ARBs, MRAs before starting Ivabradine; and Ivabradine should not be used as an alternative of beta blockers.