The following is a summary of “Differing Response to Left Bundle Branch Area Pacing versus Biventricular Pacing for Cardiac Resynchronization According to Septal Scar Burden Among Non-ischemic Cardiomyopathy Patients,” published in the November 2023 issue of Cardiology by Chen et al.

Uncertain if Left Bundle Branch Area Pacing (LBBAP) mimics the benefits of Biventricular Pacing (BVP) for Cardiac Resynchronization Therapy (CRT) in Non-Ischemic Cardiomyopathy (NICM) patients with varying degrees of Septal Scar Burden (SSB).

Researchers conducted a  retrospective study to evaluate whether septal scar burden influences the response to LBBAP versus BVP in NICM patients undergoing CRT.

They included non-ischemic cardiomyopathy (NICM) patients with a vast QRS complex and CRT indications who had undergone pre-procedure cardiac magnetic resonance (CMR) examination. Either BVP or LBBAP were received. Late gadolinium enhancement (LGE) was analyzed for scar quantification. CRT response was defined as an absolute increase of ≥ 5% in left ventricular ejection fraction (LVEF) at the 6-month follow-up.

The results showed 147 patients, 34.7% (51) receiving LBBAP and 65.3% (96) receiving BVP. As the septal LGE extent increased, the improvement in LVEF at the 6-month follow-up gradually decreased in the BVP group and dropped sharply in the LBBAP group. A nonlinear inverse relationship was observed between the relative benefit of LBBAP versus BVP for response and septal LGE extent, along with determined cut-off points (4.4%, 13.3%) of septal LGE extent using a restricted cubic spline model. Among patients with low septal scar extent (<4.4%), LBBAP was associated with higher response odds than BVP [OR 3.87, 95% CI: 0.99-15.17, P=0.052]. In the medium septal scar extent group (4.4%-13.3%), response odds did not differ between LBBAP and BVP (OR 2.00, 95% CI: 0.41-9.74, P=0.391). Among patients with high septal scar extent (>13.3%), BVP was associated with higher response odds (OR 0.12, 95% CI: 0.03-0.54, P=0.006).

They concluded that NICM CRT patients’ responses to LBBAP and BVP diverged with varying septal scar burden.

Source: ahajournals.org/doi/10.1161/circ.148.suppl_1.12377