Accelerated graft dysfunction in heart transplant patients with persistent atrioventricular conduction block.
AIMS
Bradyarrhythmia following heart transplantation is common-∼7.5-24% of patients require permanent pacemaker (PPM) implantation. While overall mortality is similar to their non-paced counterparts, the effects of chronic right ventricular pacing (CRVP) in heart transplant patients have not been studied. We aim to examine the effects of CRVP on heart failure and mortality in heart transplant patients.


METHODS AND RESULTS
Records of heart transplant recipients requiring PPM at St Vincent's Hospital, Sydney, Australia between January 1990 and January 2015 were examined. Patient's without a right ventricular (RV) pacing lead or a follow-up time of <1 year were excluded. Patients with pre-existing abnormal left ventricular function (<50%) were analysed separately. Patients were grouped by pacing dependence (100% pacing dependent vs. non-pacing dependent). The primary endpoint was clinical or echocardiographic heart failure (<35%) in the first 5 years post-PPM. Thirty-three of 709 heart transplant recipients were studied. Two patients had complete RV pacing dependence, and the remaining 31 patients had varying degrees of pacing requirement, with an underlying ventricular escape rhythm. The primary endpoint occurred significantly more in the pacing-dependent group; 2 (100%) compared with 2 (6%) of the non pacing dependent group (P < 0.0001 by log-rank analysis, HR = 24.58). Non-pacing-dependent patients had reversible causes for heart failure, unrelated to pacing. In comparison, there was no other cause of heart failure in the pacing-dependent group.


CONCLUSIONS
Permanent atrioventricular block is rare in the heart transplant population. We have demonstrated CRVP as a potential cause of accelerated graft failure in pacing-dependent heart transplant patients.
['Lee|William|W|', 'Tay|Andre|A|', 'Walker|Bruce D|BD|', 'Kuchar|Dennis L|DL|', 'Hayward|Christopher S|CS|', 'Spratt|Phillip|P|', 'Subbiah|Rajesh N|RN|']
D000328:Adult D054537:Atrioventricular Block D001315:Australia D001919:Bradycardia D002304:Cardiac Pacing, Artificial D004452:Echocardiography D005260:Female D005500:Follow-Up Studies D006333:Heart Failure D016027:Heart Transplantation D006352:Heart Ventricles D006801:Humans D053208:Kaplan-Meier Estimate D008297:Male D008875:Middle Aged D010138:Pacemaker, Artificial D055031:Primary Graft Dysfunction D012189:Retrospective Studies D018487:Ventricular Dysfunction, Left
Heart transplant Pacemaker Heart failure Complete heart block Pacemaker dependent Pacing-induced cardiomyopathy