Hypothesis: To define the risk of stroke in patients with PFO and intracardiac devices with or without traditional risk factors
Background: Risk of stroke in patients with known patent foramen ovale (PFO) and no other independent predictors of stroke is not known
Methods: We retrospectively identified all consecutive patients (n= 7893) with PFO within a large health care network of hospitals with common electronic medical record. Patients were divided into two groups- device present vs device absent (based on presence/absence of intracardiac devices like pacemakers or implantable cardioverter-defibrillators). Patients were subsequently stratified into low or elevated stroke risk based on presence or absence of independent stroke risk factors like hypertension, diabetes, heart failure and age>60. Patients were followed over 10 years for stroke
Results: In the overall population, the incidence rate of stroke per 100 patient-years in low stroke risk group vs elevated stroke risk group was 0.5% vs 5.04% respectively (p<0.01). In low stroke risk group with known PFO, presence of intracardiac device increased the hazard of stroke by 5.9 folds compared to patients with no intracardiac device (HR 5.9, 95%CI 3.4- 10.3, P<0.0001, Figure 1). Amongst patients with elevated baseline stroke risk group, presence of intracardiac device did not increase the risk of stroke (HR 1.03, 95% CI 0.85- 1.25, P=0.71, Figure 1).
Conclusion: Amongst patients with PFO and no other risk factors for stroke, implantable intracardiac devices significantly increase the risk of stroke. Our findings need to be confirmed in a larger, prospective trial.