Standardized Mortality Ratio and Long-Term Stroke Incidence After PFO Closure: A Register Study

Closure of a patent foramen ovale (PFO) is frequently recommended in patients with cryptogenic stroke. Long-term outcomes in real-world settings remain unknown.

This study analyzed standardized mortality ratio (SMR), subsequent stroke, and associated risk factors after PFO closure.

National registers on congenital heart disease and stroke were cross-linked to identify individuals who underwent PFO closure between 2001 and 2018. The ratio of observed to expected deaths was calculated (SMR). Data were analyzed using survival analysis and Cox regression.

A total of 827 patients (60.5% males, median age 47.9 years, IQR: 40.0-55.6 at the time of PFO closure) were included and observed for a median duration of 8.0 years (IQR: 4.8-11.0). During follow-up, 23 patients died, SMR was 0.65 (95% CI: 0.41-0.98). A total of 34 ischemic strokes occurred, yielding an incidence rate of 0.51 events per 100 patient-years. Among the 34 patients who experienced a subsequent stroke, 27 were receiving antithrombotic therapy at the time of the event. New-onset atrial fibrillation following PFO closure was associated with an increased risk of subsequent ischemic stroke (HR: 8.2; 95% CI: 2.6-25.8), as was active/previous smoking (HR: 2.5; 95% CI: 1.2-5.1).

Patients undergoing PFO closure demonstrated a lower all-cause mortality compared to the general population. The observed rate of subsequent ischemic stroke was consistent with findings from previous randomized controlled trials. New-onset atrial fibrillation following PFO closure and active/previous smoking emerged as modifiable risk factors.