Stroke or Transient Ischemic Attack in Patients With Transvenous Pacemaker or Defibrillator and Echocardiographically Detected Patent Foramen Ovale

Abstract

15% of patients within 2 weeks of device implantation without heparin prophylaxis, 8 and, at autopsy, pulmonary emboli were present in 21% of patients with CIEDs. 6 A study using intracardiac echocardiography at the time of a planned electrophysiological procedure found mobile thrombi attached to leads in 30% of patients. 9 These thrombi were rarely seen with the use of transthoracic echocardiography (TTE), reflecting their small size. Moreover, the presence of lead-related thrombi was associated with increased pulmonary artery systolic pressure, suggesting subclinical pulmonary embolic events.9 Elevated pulmonary artery pressures may in turn increase the likelihood of right-to-left shunting across a patent foramen ovale (PFO). Clinical Perspective on p 1441Background-A patent foramen ovale (PFO) may permit arterial embolization of thrombi that accumulate on the leads of cardiac implantable electronic devices in the right-sided cardiac chambers. We sought to determine whether a PFO increases the risk of stroke/transient ischemic attack (TIA) in patients with endocardial leads. Methods and Results-We retrospectively evaluated all patients who had endocardial leads implanted between January 1, 2000, and October 25, 2010, at Mayo Clinic Rochester. Echocardiography was used to establish definite PFO and non-PFO cohorts. The primary end point of stroke/TIA consistent with a cardioembolic etiology and the secondary end point of mortality during postimplantation follow-up were compared in PFO versus non-PFO patients with the use of Cox proportional hazards models. We analyzed 6075 patients (364 with PFO) followed for a mean 4.7±3.1 years. The primary end point of stroke/TIA was met in 30/364 (8.2%) PFO versus 117/5711 (2.0%) non-PFO patients (hazard ratio, 3.49; 95% confidence interval, 2.33-5.25; P<0.0001). The association of PFO with stroke/TIA remained significant after multivariable adjustment for age, sex, history of stroke/TIA, atrial fibrillation, and baseline aspirin/warfarin use (hazard ratio, 3.30; 95% confidence interval, 2.19-4.96; P<0.0001). There was no significant difference in all-cause mortality between PFO and non-PFO patients (hazard ratio, 0.91; 95% confidence interval, 0.77-1.07; P=0.25). Conclusions-In patients with endocardial leads, the presence of a PFO on routine echocardiography is associated with a substantially increased risk of embolic stroke/TIA. This finding suggests a role of screening for Up to 25% of the population may have a PFO detectable on autopsy, with persistence after the birth of a connection between the right and left atria. 10,11 In patients with elevated right-sided pressures, flow through a PFO provides a mechanism of blood flow from the right heart to the left-sided circulation. In patients with a PFO, endovascular leads may pose a unique hazard, because the thrombi that develop on leads may shunt across the PFO to the systemic circulation, resulting in ischemic cerebrovascular events or other systemic thromboembolisms. We have previously published 2 case series on device...

Ischemic Stroke or Systemic Embolism After Transseptal Ablation of Arrhythmias in Patients With Cardiac Implantable Electronic Devices

“…Mobile thrombi attached to CIED leads have been reported in 30% of patients imaged with intracardiac echocardiography in one series, with the majority occurring in the right atrium 8. We have previously shown an increased propensity for stroke or TIA in patients with a CIED and patent foramen ovale 18. We propose that the increased risk for systemic embolic events in the current study may be the result of paradoxical embolism of thrombi originating from CIED leads.…”

Implanted endocardial lead characteristics and risk of stroke or transient ischemic attack

“…Endocardial leads frequently have thrombus formation [4–7] that can result in subclinical pulmonary embolisms [8–11]. Lead-related thrombi can result in paradoxical systemic embolization through a PFO or intrapulmonary shunts, leading to stroke or transient ischemic attack (TIA) [12–16]. …”

“…We have recently demonstrated in a large retrospective study that patients with endocardial leads and a PFO are at a substantially increased risk of stroke/TIA as compared to patients with endocardial leads but no documented PFO [16]. In that study, PFOs were mostly diagnosed on routine echocardiography with non-standardized utilization of color Doppler and agitated saline injection.…”

Iatrogenic atrial septal defect: reassurance or inquisitiveness

“…High-risk characteristics of PFO include moderate-to-large right-to-left shunt, large PFO size (more than 8.0 × 8.0 mm) and concomitant atrial septal aneurysm [3][4][5]. Observational studies also found an association between PFO and paradoxical emboli in the setting of pre-existing cardiac implantable electronic devices (CIEDs) [6]. During transvenous lead extraction, debris surrounding the extracted leads can be dislodged through the preexisting PFO.…”