Risk of Stroke in Patients With Patent Foramen Ovale Who Had Pulmonary Embolism

The presence of patent foramen ovale (PFO) alone does not increase the risk of ischemic stroke. Several prospective studies with a small number of patients have shown that the risk of ischemic stroke is higher in patients with PFO and pulmonary embolism (PE). We studied the association of ischemic stroke in the patients who had PFO with PE (PFOwiPE) and compared with the patients who had PFO without PE (PFOwoPE).

Electronic medical records of 154 adult patients in our internal medicine office were reviewed. Thirty-four patients had PFOwiPE and 120 had PFOwoPE. Independent t-test and Mann-Whitney U-test were used to compare the continuous variables between the two groups, while Chi-square tests were applied to compare the categorical variables between the two groups. Logistic regression was used for multivariate analysis. The dependent variable was stroke and the independent variable of interest was PFO with, or without PE.

Mean age of patients with PFOwiPE was 54.8 years and patients with PFOwoPE was 57.8 years (P = 0.331). Mean body mass index (BMI) of the patients with PFOwiPE was significantly greater than the patients with PFOwoPE (32.5 ± 8.84 kg/m² vs. 28.4 ± 6.99 kg/m²; P < 0.05). Mean left ventricular ejection fraction (LVEF) and red blood cell (RBC) count of patients with PFOwiPE was significantly lower than patients with PFOwoPE (LVEF 54.9 ± 13.01% vs. 59.6 ± 6.85%, P < 0.05; RBC 4.1 ± 1.203 × 10⁶/µL vs. 4.5 ± 0.596 × 10⁶/µL, P < 0.05). There was significantly higher association of congestive heart failure (CHF) in patients with PFOwiPE compared to patients with PFOwoPE (20.6% vs. 7.5%; P < 0.05). Association of ischemic stroke was 35.3% in patients with PFOwiPE and 39.2% in patients with PFOwoPE. The difference was not statistically significant (P = 0.682).

Association of ischemic stroke was similar in patients with PFOwiPE and patients with PFOwoPE. Association of significantly higher BMI, lower LVEF, lower RBC count, and higher frequency of CHF were associated with patients with PFOwiPE compared to the patients with PFOwoPE.