Second Department of Internal Medicine, University of Toyama.
Int Heart J. 2021 Nov 30;62(6):1305-1309. doi: 10.1536/ihj.21-387. Epub 2021 Nov 6.
Ivabradine, which reduces heart rate (HR) without affecting sympathetic nerve activity, improves mortality and morbidity in patients with systolic dysfunction. However, its impact on up-titrating a concomitant beta-blocker dose in such a cohort, via increasing cardiac output and blood pressure and improving tolerability to beta-blockers, remains unknown. In this single-center, prospective, randomized control trial, patients with systolic dysfunction, defined as left ventricular ejection fraction < 50%, sinus rhythm, heart rate > 75 bpm, systolic blood pressure between 90 and 110 mmHg, and New York Heart Association functional class III or IV, who are refractory to up-titration of a beta-blocker due to symptomatic hypotension, dizziness, or worsening heart failure, were assigned to the 20 ivabradine arm or the 20 conventional therapy arm and followed-up for 6 months. The primary outcome is the daily dose of beta-blocker at 6-months follow-up. The secondary outcomes are echocardiographic parameters including overlap between E-wave and A-wave in transmitral diastolic filling flow, plasma B-type natriuretic peptide level, 6-minute walk distance, and heart failure readmission rate. By conducting this study, we hope to demonstrate the clinical benefit of ivabradine therapy in up-titrating beta-blockers and improving clinical outcomes in patients with systolic dysfunction.
伊伐布雷定可降低心率（HR）而不影响交感神经活动，可改善收缩功能障碍患者的死亡率和发病率。然而，其通过增加心输出量和血压以及提高对β受体阻滞剂的耐受性来增加同时使用的β受体阻滞剂剂量的影响在这类患者中尚不清楚。在这项单中心、前瞻性、随机对照试验中，入选了收缩功能障碍患者，定义为左心室射血分数 < 50%、窦性心律、心率 > 75 次/分、收缩压在 90-110mmHg 之间、纽约心脏协会心功能分级 III 或 IV 级，因低血压、头晕或心力衰竭恶化而对β受体阻滞剂的剂量递增不耐受的患者，随机分配至伊伐布雷定 20mg 组或常规治疗 20mg 组，并随访 6 个月。主要结局为 6 个月随访时β受体阻滞剂的日剂量。次要结局为超声心动图参数，包括二尖瓣舒张充盈血流中 E 波与 A 波重叠、血浆 B 型利钠肽水平、6 分钟步行距离和心力衰竭再入院率。开展这项研究，我们希望证明伊伐布雷定治疗在增加β受体阻滞剂剂量和改善收缩功能障碍患者临床结局方面的临床获益。
