Abstract 18929: Pacing in the Adult Fontan Patient: Risky Business?

Abstract

Introduction: Chronic ventricular pacing can induce a cardiomyopathy in patients with a biventricular heart; however, the effect of chronic pacing in adult patients with a Fontan has not been well characterized. We hypothesized that paced adult Fontan patients would be at higher risk for death or heart transplant. Methods: We performed a retrospective, cohort of study of all adult Fontan patients at the Schneeweiss Adult Congenital Heart Center seen between 1/1997 and 5/2014. Two Cohorts were defined based on whether a patient did or did not have a permanent pacemaker. Demographic and clinical characteristics were collected via chart review. The primary endpoint was a composite of death or heart transplant. Results: Of the 98 adult Fontan patients followed (mean age at last follow-up 32± 8 years), 30 (31%) had a pacemaker. Pacemaker specific data was available on 25 of the 30 (83%) paced patients. Of those, 88% were paced >50% of the time. Patient diagnoses included double inlet left ventricle in 33 (34%), tricuspid atresia in 26 (27%), hypoplastic left heart in 9 (9%), heterotaxy in 8 (8%), and 22 (22%) with other diagnoses. Fifty-two patients (53%) had a classic RA-PA Fontan and 46 (47%) had a lateral tunnel or extracardiac Fontan. Over the study period, 16 patients met the primary endpoint and 12 (75%) were paced. Paced patients were significantly more likely to have worse functional status (p<0.001), be on diuretics (p<0.001), and have a higher mean creatinine (P=0.025), mean total bilirubin (p=0.025), and mean Fontan pressure (p<0.001). Pacing was associated with >4-fold increase in the rate of death or heart transplant (p=0.009) in a multivariate cox-proportional hazard model that included Fontan type, age at Fontan completion, age at follow-up, and pacing status. Discussion: In our cohort of 98 adult Fontan patients, paced patients were more likely to have worse functional status, require diuretics and had a >4-fold increased risk of death or heart transplant. These results suggest that chronic pacing may be detrimental in this population.