Transvenous pacing leads and systemic thromboemboli in patients with intracardiac shunts: a multicenter study.
BACKGROUND
The risk of systemic thromboemboli associated with transvenous leads in the presence of an intracardiac shunt is currently unknown.


RESULTS
To define this risk, we conducted a multicenter, retrospective cohort study of 202 patients with intracardiac shunts: Sixty-four had transvenous leads (group 1), 56 had epicardial leads (group 2), and 82 had right-to-left shunts but no pacemaker or implantable cardioverter defibrillator leads (group 3). Patient-years were accrued until the occurrence of systemic thromboemboli or study termination. Censoring occurred in the event of complete shunt closure, death, or loss to follow-up. Mean ages for groups 1, 2, and 3 were 33.9+/-18.0, 22.2+/-12.6, and 22.9+/-15.0 years, respectively. Respective oxygen saturations were 91.2+/-9.1%, 88.1+/-8.1%, and 79.7+/-6.7%. During respective median follow-ups of 7.3, 9.3, and 17.0 years, 24 patients had at least 1 systemic thromboembolus: 10 (15.6%), 5 (8.9%), and 9 (11.0%) in groups 1, 2, and 3, respectively. Univariate risk factors were older age (hazard ratio [HR], 1.05; P=0.0001), ongoing phlebotomy (HR, 3.1; P=0.0415), and an transvenous lead (HR, 2.4; P=0.0421). In multivariate, stepwise regression analyses, transvenous leads remained an independent predictor of systemic thromboemboli (HR, 2.6; P=0.0265). In patients with transvenous leads, independent risk factors were older age (HR, 1.05; P=0.0080), atrial fibrillation or flutter (HR, 6.7; P=0.0214), and ongoing phlebotomy (HR, 14.4; P=0.0349). Having had aspirin or warfarin prescribed was not protective. Epicardial leads were, however, associated with higher atrial (P=0.0407) and ventricular (P=0.0270) thresholds and shorter generator longevity (HR, 1.9; P=0.0176).


CONCLUSIONS
Transvenous leads incur a >2-fold increased risk of systemic thromboemboli in patients with intracardiac shunts.
Khairy
Paul
P
Adult Congenital Heart and Electrophysiology Services, Montreal Heart Institute, Montreal, Canada. paul.khairy@umontreal.ca
Landzberg
Michael J
MJ
Gatzoulis
Michael A
MA
Mercier
Lise-Andrée
LA
Fernandes
Susan M
SM
Côté
Jean-Marc
JM
Lavoie
Jean-Pierre
JP
Fournier
Anne
A
Guerra
Peter G
PG
Frogoudaki
Alexandra
A
Walsh
Edward P
EP
Dore
Annie
A
D001166:Arteriovenous Shunt, Surgical / Q000379:methods*; D002304:Cardiac Pacing, Artificial; D015331:Cohort Studies; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000145:classification / Q000453:epidemiology / Q000601:surgery*; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000453:epidemiology; D010138:Pacemaker, Artificial; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013923:Thromboembolism / Q000453:epidemiology / Q000601:surgery*