Abstract 2972: Permanent Atrial Pacing Lead Implantation Route After Fontan Operation
Background: Atrial pacing is commonly used for sinus node dysfunction (SND) after Fontan surgery. The preferred route of lead implant has been debated. We compare procedural and clinical outcomes of transvenous (TV) and epicardial (Epi) atrial lead implants in this population.
Methods: All Fontan patients having an atrial lead implant without other associated surgery between 1992 and 2007 were studied. Demographics, pacing lead performance data and procedural outcome were retrospectively analyzed.
Results: 78 patients (22 TV and 56 Epi) had 90 leads implanted (25 TV/ 65 Epi). Mean follow-up was 3.3±4.1 yrs (TV) and 4.4±3.6 yrs (Epi). TV leads were implanted in older patients (mean age: 23.9 vs. 13.8 yrs, p<0.001), at longer interval after Fontan surgery (mean: 15.1 vs. 5.7 yrs, p<0.001). Indication for TV was more likely to be SND, while Epi pacing was indicated for AV block. Pacing modes were exclusively AAI/AAI-T in TV and mostly DDD in Epi leads. Acute complication occurred in 2/25 (8%) of TV (pneumothorax n=1, skin erosion n=1) and 12/65 (19%, p=0.23) of Epi implants (effusions n=5, heart failure n=1, retained foreign body n=1, pneumothorax n=1, hematoma n=1, disconnection n=1, sepsis n=1, blood loss n=1). Median hospital stay was shorter in TV (2.0 vs 4.5 days, p=0.03). All TV patients and 43 Epi (77%) were anticoagulated. At follow-up, pocket infection occurred in one Epi patient. No clinical thromboembolic event was observed in either group. 3 TV leads failed in 2 patients (9%), while 12 Epi leads failed in 10 patients (18%); however, mean duration of freedom from lead failure was not significantly different (TV 9.9 vs. Epi 8.0 yrs, P=ns). The mean energy threshold was lower at implant for TV leads (0.9 vs 2.2 μJ, P=0.049), but similar for both leads on follow-up (1.2 vs 2.6 μJ, P=0.35). Atrial sensing was unchanged over time for TV (2.2 to 2.0 mV, P=ns), but significantly decreased in Epi (3.4 to 2.4 mV, p=0.006).
Conclusions: Transvenous atrial pacing leads may be placed in Fontan patients with lower procedural morbidity than epicardial leads, and equivalent expectation of lead performance and longevity. Although the thromboembolic event rate appears low in anticoagulated patients with both lead types, the present study design cannot fully address this important issue.