Abstract 13067: Conduction System Pacing to Achieve Cardiac Resynchronization Therapy: Is There a Sex Difference in Response Rates?

Background: It is well established that in patients with dyssynchronous heart failure related to left bundle branch block (LBBB) and reduced left ventricular ejection fraction (LVEF), females show higher response rates than males when cardiac resynchronization (CRT) is achieved by conventional biventricular (BiV) pacing. Whether this sex difference is also true when CRT is achieved via conduction system pacing is unknown.

Hypothesis: There is no difference between women and men in response rates when CRT is achieved by conduction system pacing (CSP), either by His bundle pacing (HBP) or by left bundle area pacing (LBAP).

Methods: Patients who underwent CSP with a baseline LVEF ≤40% and a QRS duration ≥140 milliseconds (ms) were retrospectively selected from a CSP database maintained at our institution. 52 patients were included: 17 females and 35 males. Baseline clinical, electrocardiographic, echocardiographic, and follow up data were gathered and analyzed. Electrocardiograms and echocardiograms closest to the dates of implant and at last known follow up were used. Super-response was defined as absolute EF improvement ≥15%.

Results: At baseline, there were no statistically significant differences in clinical, electrocardiographic, and echocardiographic characteristics between females and males except for higher prevalence of coronary disease in men, and higher percentage use of guideline directed medical therapy in men (Table 1). At median follow up of 113 days, there were no differences in electrocardiographic or echocardiographic response, number of super-responders, and mortality between females and males (Table 1).

Conclusions: Unlike conventional CRT where females show superior response rates, CRT with CSP seems to provide comparable benefits in females and males. If confirmed in larger data sets, this may represent an important advantage of CSP over conventional CRT.