Transvenous Pacing Leads and Systemic Thromboemboli in Patients With Intracardiac Shunts

Abstract

Background— The risk of systemic thromboemboli associated with transvenous leads in the presence of an intracardiac shunt is currently unknown. Methods and 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.

A computer modeling tool for comparing novel ICD electrode orientations in children and adults

“…Transvenous implantation often cannot be performed in children due to patient size, lack of vascular access and increased risk of embolic phenomena due to intracardiac shunts. 5,31 Children with ICDs have high rates both of lead failure and vascular occlusion, and also have long life expectancy compared to adult patients, resulting in the anticipated need for repeated lead extraction and reimplantation with their attendant risks. 1,6 There is now also growing interest in the development of extracardiac, subcutaneous ICDs for the adult population with normal cardiac anatomy, with the goal of simplifying ICD implantation, avoiding lead related complications, and/or addressing vascular access problems or other contraindications to transvenous implant.…”

Prevention and Treatment of Thrombosis in Pediatric and Congenital Heart Disease

“…Hemodynamic evaluation demonstrated a brief shunt reversal, creating a paradoxical right-to-left shunt through the defect. Khairy et al 532 demonstrated that transvenous leads were a multifactorial independent risk for emboli regardless of shunt direction. In addition, some patients had embolic complications despite aspirin or warfarin with a therapeutic INR.…”

Transvenous pacing after the Mustard procedure: considering the complications

“…14 The presence of an intracardiac shunt, including baffle leak, increases the risk of paradoxical thromboembolic events arising from transvenous leads >2-fold. 15 Although there are few data, anticoagulation therapy should be considered in patients with intracardiac shunts receiving transvenous leads.…”