Incidence and predictors of late atrioventricular conduction recovery among patients requiring permanent pacemaker for complete heart block after cardiac surgery.

BACKGROUND

New-onset complete heart block (CHB) commonly complicates cardiac surgery, for which some patients require a permanent pacemaker (PPM). Little is known regarding late atrioventricular (AV) conduction recovery.

OBJECTIVE

The purpose of this study was to characterize the incidence and predictors of late AV conduction recovery among patients requiring PPM after cardiac surgery.

METHODS

Consecutive patients receiving PPM for CHB after cardiac surgery at a high-volume U.S. center from 2000 to 2014 were evaluated. The primary outcome was late AV conduction recovery, defined as a reduction in ventricular pacing requirement to <10% beyond 1 month postimplant. Regression analysis was performed to evaluate predictors of AV recovery.

RESULTS

Among 301 patients evaluated over 4 ± 4 years of follow-up, the incidence of late AV conduction recovery was 12% (n = 37), for whom the median ventricular pacing requirement decreased from 96% at implant to <1% at 6 months and persisted throughout study follow-up. AV recovery was less common when preoperative conduction abnormalities were present, including no recovery among patients with preoperative PR >200 ms and QRS >120 ms (n = 42). Multivariable analysis identified only female sex and transient AV conduction postoperatively as independent predictors of recovery (odds ratio 3.5; P <.01 for each). Neither cardiac surgery subtype nor PPM implant timing postoperatively was significantly associated with recovery.

CONCLUSION

Late AV conduction recovery is not uncommon after cardiac surgery, occurring in 1 of 8 patients within 6 months postoperatively. Preoperative AV conduction abnormalities were associated with decreased recovery, whereas female sex and transient postoperative AV conduction were associated with increased recovery.