The Pacing to Avoid Cardiac Enlargement (PACE) trial: clinical background, rationale, design, and implementation

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Medical Device Research

Background:

• Conventional right ventricular apical (RVA) pacing can negatively impact left ventricular (LV) function.
• Biventricular pacing (BiV) shows potential benefits, especially in patients with LV systolic dysfunction.
• Optimal pacing strategies for patients with normal LV systolic function are not well-established.

Purpose of the Study:

• To evaluate if biventricular pacing (BiV) is superior to conventional right ventricular apical (RVA) pacing in preserving LV systolic function.
• To determine if BiV pacing prevents adverse LV remodeling in patients with normal LV ejection fraction (EF) and a pacing indication.
• To compare the effects of atrial-based RVA pacing versus BiV pacing over one year.

Main Methods:

• The Pacing to Avoid Cardiac Enlargement (PACE) trial is a prospective, multicenter, randomized, double-blinded, controlled study.
• 200 patients with LV EF ≥ 45% received BiV pacemaker implantation and were randomized to RVA or BiV pacing for 1 year.
• Primary endpoints include changes in LV end-systolic volume and LVEF at 1 year, with assessments of exercise capacity, quality of life, and neurohormones.

Main Results:

• This section is not available in the provided abstract.
• The study is designed with 90% power to detect a 5% difference in LVEF.
• Enrollment occurred from 2006 to 2008.

Conclusions:

• The PACE trial aims to clarify whether atrial-based BiV pacing preserves LV systolic function and prevents adverse LV remodeling compared to conventional RVA pacing.
• Findings will inform optimal pacing strategies for patients with normal LV systolic function requiring pacing.