Different ventricular remodelling and autonomic modulation after long-term beta-blocker treatment in hypertensive, ischaemic and idiopathic dilated cardiomyopathy

OBJECTIVE: In this retrospective analysis, we investigated the influence of aetiology on autonomic modulation and reverse ventricular remodelling induced by β-blockade in heart failure. METHODS: Twenty-three heart failure patients without comorbidities (mean age 61 ± 4 years, New York Heart Association class 3.1 ± 0.1, treated with angiotensin-converting enzyme inhibitors and diuretics) were divided into three groups according to aetiology: hypertensive (group 1, n = 7), ischaemic (group 2, n = 6), and idiopathic (group 3, n = 10). Before and after 6 months of carvedilol (53 ± 10 mg/day), patients underwent cardiopulmonary test, echocardiography and autonomic evaluation with spectral analysis of RR variability (10 min of rest plus 10 min of standing: the low frequency/high frequency ratio between low and high frequency components of each spectrum was the index of sympathovagal balance). RESULTS: Carvedilol improved New York Heart Association class and exercise performance. In group 1, ejection fraction and left ventricular end-diastolic volume normalised, and interventricular septum thickness increased. No remodelling occurred in group 2. In group 3, interventricular septum thickness was unchanged, ejection fraction and left ventricular end-diastolic volume improved. Also autonomic modulation differed. At baseline, adrenergic activation was observed either at rest or during standing. After carvedilol treatment, group 1 did not show any change in the low frequency/high frequency ratio in both conditions, whereas groups 2 and 3 showed reduced adrenergic activation at rest and normal response to standing. CONCLUSIONS: Despite favourable ventricular remodelling, the poor autonomic modulation observed with β-blockade indicates a persistent central adrenergic activation in hypertensive heart failure patients.