Randomized Trial of Left Bundle Branch Pacing vs Right Ventricular Pacing in Vulnerable Cardiac Function

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Right ventricular pacing (RVP) is linked to pacing-induced cardiomyopathy (PICM) in patients with high pacing burden.
• Left bundle branch pacing (LBBP) offers a more physiological alternative that may preserve cardiac function.

Purpose of the Study:

• To compare the clinical outcomes of LBBP versus RVP in high-risk patients with high pacing burden.
• To evaluate LBBP's efficacy in preventing cardiac dysfunction and improving heart function.

Main Methods:

• A prospective, multicenter, randomized controlled trial involving 160 patients.
• Patients were randomized 1:1 to LBBP or RVP.
• Primary endpoint: composite of mortality, heart failure hospitalization (HFH), or PICM; follow-up: 36 months.

Main Results:

• LBBP significantly reduced the primary composite endpoint (11.6% vs. 33.9%, P=0.001), primarily due to lower PICM rates (6.5% vs. 18.2%, P=0.028).
• LBBP demonstrated superior improvements in left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD).
• Patients receiving LBBP showed improved New York Heart Association (NYHA) functional class compared to RVP.

Conclusions:

• LBBP is a superior pacing strategy in high pacing burden patients at risk for cardiac dysfunction.
• LBBP significantly reduces PICM and improves echocardiographic and functional outcomes compared to RVP.
• Findings support LBBP as a preferred pacing method and warrant further investigation in larger trials.