Abstract 18727: Incidence and Clinical Predictors of Late Atrioventricular Conduction Recovery Among Patients Requiring Pacemaker for Complete Heart Block After Cardiac Surgery

BackgroundThe incidence and clinical predictors of atrioventricular (AV) conduction recovery among patients requiring pacemaker (PM) for complete heart block (CHB) after cardiac surgery are unknown.MethodsConsecutive patients receiving PM for new CHB following cardiac surgery at a high-volume US center from 2000-2014 were evaluated, excluding biventricular PM and PM implanted after the index surgical hospitalization. The primary outcome was AV nodal conduction recovery, defined as a reduction in ventricular pacing to 1 month post-implant. Multi-variable analysis was performed via logistic regression.Results326 patients (66 ± 14 years, 57% male) were retained over 4.2 ± 4.1 years follow-up. Late AV conduction recovery occurred in 11.4% of patients (n = 37). The median ventricular pacing requirement for patients with recovery decreased from 96% at implant to 6% at 1 month and 0% at 6 months. Recovery was less common for patients with prolonged pre-operative conduction, including PR (181 ± 34 msec recovery vs. 198 ± 57 msec none, ρ=0.03) and QRS (103 ± 22 msec recovery vs. 118 ± 28 msec none, ρ120 msec demonstrated recovery (n = 45, 14%). In multi-variable analysis, only female gender (HR 0.38, ρ=0.01), tricuspid valve surgery (HR 0.30, ρ=0.03), and transient intact post-operative AV conduction (HR 0.33, ρ=0.03) were independently associated with recovery. There were otherwise no differences by surgery subtype nor timing from surgery to PM implant (Table 1).ConclusionsLate AV conduction recovery is uncommon among patients requiring PM for CHB following cardiac surgery, particularly with prolonged pre-operative AV conduction. Only female gender, tricuspid valve surgery, and transient intact post-operative AV conduction were independently associated with recovery.