Comparison of left bundle branch area pacing between patients with pacing-induced cardiomyopathy and non-ischemic dilated cardiomyopathy

Introduction

Left bundle branch area pacing (LBBAP) seems to be an alternative to coronary sinus pacing in patients with non-ischaemic dilated cardiomyopathy (NI-DCM) with left bundle branch block (LBBB) and in pacing-induced cardiomyopathy (PICM). The aim of the study was to compare the response of LBBAP in severe forms of both entities.

Material and methods

Prospective study of patients with severe forms of PICM and NI-DCM in NYHA II-IV who underwent LBBAP. Clinical, electrocardiographic, echocardiographic and electrical parameters were analysed and the medium-term prognostic impact was assessed.

Results

Eighty patients were included, 25 with PICM and 55 with NI-DCM. PICM patients were older (PICM 75 [IQR 71-83.5] y.o vs NI-DCM 72 [IQR 60-78.5] y.o;p=0.01) and with longer baseline QRS duration (PICM 180 [IQR 167-194] ms vs NI-DCM 168 [IQR 153-178] ms;p<0.01), with no differences in left ventricular ejection fraction (LVEF) or medical treatment. QRS reduction occurred in both groups, being greater in PICM (PICM CI 95% 54±20 ms, p<0.01; NI-DCM CI 95% 40±15 ms;p<0.01). A NT-ProBNP levels reduction and LVEF improvement were observed without differences between groups. At follow-up, there were no differences in admissions for HF (PICM 4.2% vs NI-DCM 11%;p=0.413), cardiac mortality (PICM 14.9% vs NI-DCM 2.9%;p=0.13) and all-cause mortality (PICM 21.7% vs NI-DCM 10.9%;p=0.08).

Conclusion

LBBAP is an effective technique with a NT-ProBNP levels reduction and LVEF improvement in both groups without differences. At follow-up, both groups had a low rate of HF readmissions and there was a non-significant trend toward higher total mortality in PICM.