Abstract
BACKGROUND: The effect of ranolazine (RAN) on cardiac autonomic balance in congestive heart failure (CHF) was studied. METHODS: Fifty-four CHF patients were randomized to (1) open-label RAN (RANCHF) added to usual therapy vs. (2) usual therapy (NORANCHF). Parasympathetic and sympathetic (P&S) measurements were taken at baseline and at 12 months. RESULTS: A total of 16/27 (59%) patients in both groups had initially abnormal P&S measures, including high sympathovagal balance (SB), cardiovascular autonomic neuropathy (CAN) or both. High SB normalized in 10/12 (83%) RANCHF patients vs. 2/11 (18%) NORANCHF patients. SB became high in 5/11 (45%) NORANCHF vs. 1/11 (9%) RANCHF patients. CAN improved in 4/6 (67%) RANCHF patients vs. 5/7 (45%) NORANCHF patients. CAN developed in 1/11 (9%) RANCHF vs. 4/11 (36%) NORANCHF patients. Since improved P&S in RANCHF patients seemed independent of improved brain natriuretic peptide and impedance cardiography (BioZ) measurements, 5 day RAN was given to 30 subjects without CHF but with high SB or CAN. P&S improved in 90% of these subjects. CONCLUSIONS: RAN improves unfavorable P&S activity in CHF possibly by a direct effect upon autonomic sodium channels.