Clinical implications of a patent foramen ovale in patients with massive pulmonary embolism

Summary

 The aim of our investigations was to prospectively evaluate the clinical relevance of a patent foramen ovale in patients with acute massive pulmonary embolism with regard to mortality, the occurrence of cardiovascular complications and the extent of arterial hypoxemia.

In 85 patients and in a second study in 139 patients with acute massive pulmonary embolism a right-to-left shunt was diagnosed by contrast echocardiography. A patent foramen ovale was found in 39% of the patients in the first and in 35% in the second study.

With regard to the extent of arterial hypoexemia the oxygen tension was significantly lower in patients with a patent foramen ovale (55±14 mm Hg vs 62±16 mm Hg). Furthermore in the second study, clinical symptoms presumptive of paradoxical embolism occurred in 13 patients (27%) with a patent foramen ovale and in 2 patients (2.2%) without a patent foramen ovale. During the inhospital stay, patients with a patent foramen ovale had a death rate of 33% as opposed to 14% in patients without a patent foramen ovale. Logistic regression analysis demonstrated that after adjustment for the clinical characteristics the only independent predictors of inhospital mortality were arterial hypotension at presentation (p<0.01) and a patent foramen ovale (p<0.001). Patients with a patent foramen ovale also had a significantly higher incidence of cardiovascular complications. Overall, the risk of a complicated in-hospital course was 5.2 times higher in the patient group with a patent foramen ovale.

These investigations underlines the prognostic impact of a patent foramen ovale in high-risk patients with acute massive pulmonary embolism.