Fung Jeffrey Wing-Hong, Chan Joseph Yat-Sun, Omar Razali, Hussin Azlan, Zhang Qing, Yip Gabriel, Lam Kai Huat, Fang Fang, Yu Cheuk-Man
Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
J Cardiovasc Electrophysiol. 2007 Jul;18(7):735-9. doi: 10.1111/j.1540-8167.2007.00862.x. Epub 2007 May 30.
Deleterious effect on left ventricular (LV) function was observed with conventional right ventricular apical (RVA) pacing. Preliminary data suggested that biventricular pacing (BiV) may be superior to RVA pacing in patients with LV systolic dysfunction. However, the optimal pacing mode and site(s) for patients with normal LV systolic function remain controversial.
The Pacing to Avoid Cardiac Enlargement (PACE) trial is a prospective, multicenter, randomized, double blinded, parallel, controlled study aiming to determine if BiV pacing is better than conventional RVA pacing in preserving LV systolic function and preventing remodeling in patients with LV ejection fraction (EF) > or = 45% indicated for pacing. This study targets to recruit 200 patients from various centers in Asia, all of whom will receive BiV pacemaker implantation before being randomized to either atrial-based RVA or BiV pacing for 1 year. Their echocardiographic parameters including LV volumes, left ventricular ejection fraction (LVEF), and dyssynchrony index by tissue Doppler imaging, exercise capacity, quality of life assessment, neurohormone levels, and clinical events will be assessed before and after pacing. The primary endpoints are changes in LV end-systolic volume and LVEF 1 year after pacing. It is designed with 90% power to detect a 5% difference in the LVEF after 1 year of pacing. The enrollment began in 2006. It is expected to conclude at the end of 2008.
The PACE trial will determine whether atrial-based BiV pacing can preserve LV systolic function and prevent LV adverse remodeling induced by conventional RVA pacing in patients with normal LV systolic function and standard pacing indication.
传统的右心室心尖部（RVA）起搏对左心室（LV）功能有不良影响。初步数据表明，双心室起搏（BiV）在左心室收缩功能障碍患者中可能优于RVA起搏。然而，对于左心室收缩功能正常的患者，最佳起搏模式和部位仍存在争议。
避免心脏扩大起搏（PACE）试验是一项前瞻性、多中心、随机、双盲、平行对照研究，旨在确定在左心室射血分数（EF）≥45%且有起搏指征的患者中，BiV起搏在保留左心室收缩功能和预防重塑方面是否优于传统的RVA起搏。本研究目标是从亚洲各中心招募200名患者，所有患者在随机分为心房同步RVA起搏或BiV起搏1年之前均接受BiV起搏器植入。将在起搏前后评估他们的超声心动图参数，包括左心室容积、左心室射血分数（LVEF）以及组织多普勒成像测定的不同步指数、运动能力、生活质量评估、神经激素水平和临床事件。主要终点是起搏1年后左心室收缩末期容积和LVEF的变化。该研究设计的检验效能为90%，以检测起搏1年后LVEF有5%的差异。入组于2006年开始。预计在2008年底结束。
PACE试验将确定在左心室收缩功能正常且有标准起搏指征的患者中，心房同步BiV起搏能否保留左心室收缩功能并预防传统RVA起搏引起的左心室不良重塑。
