The Suboptimal QLV Ratio May Indicate the Need for a Left Bundle Branch Area Pacing-Optimized Cardiac...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• The QLV ratio is a key intraoperative metric for predicting cardiac resynchronization therapy (CRT) efficacy.
• Suboptimal QLV ratios (<70%) may limit the effectiveness of standard biventricular CRT (Biv-CRT).

Purpose of the Study:

• To evaluate the efficacy of a QLV-ratio-based implantation strategy using Left bundle branch area pacing-optimized CRT (LOT-CRT).
• To compare LOT-CRT with standard Biv-CRT in patients with suboptimal QLV ratios.

Main Methods:

• An observational study of 72 CRT-defibrillator candidates with QRS duration ≥160 ms.
• Patients were implanted with Biv-CRT (optimal QLV ratio ≥70%) or LOT-CRT (suboptimal QLV ratio <70%).
• Follow-up was conducted for 12 months, assessing QRS width, LVEF, NYHA class, and NT-pro-BNP levels.

Main Results:

• LOT-CRT demonstrated a significantly greater reduction in QRS width compared to Biv-CRT (40.4 ± 14 ms vs. 32 ± 13 ms).
• At 12 months, LOT-CRT showed superior improvements in LVEF (14.9 ± 8% vs. 10.3 ± 7.4%), NYHA class, and NT-pro-BNP levels.
• LOT-CRT outcomes were comparable to Biv-CRT with super-optimal QLV ratios (>80%).

Conclusions:

• A QLV-ratio-based implantation strategy is feasible for CRT.
• LOT-CRT significantly improves outcomes in patients with suboptimal QLV ratios.
• Upgrading to LOT-CRT may not be necessary for Biv-CRT patients with super-optimal QLV ratios.