NEJM research: PFO closure reduces risk of recurrent stroke

The New England Journal of Medicine tackled patent foramen ovale (PFO) closure in its Sept. 13 issue, with three separate studies and an editorial devoted to the topic.

The consensus: Cryptogenic stroke patients treated with PFO closure devices showed a reduced risk of recurrent stroke but increased risk for other complications including atrial fibrillation (AFib) and venous thromboembolism.

Taken together, these findings suggest either PFO occlusion or medical therapy could be the best approach based on the patient, according to the authors of the editorial.

“The reduced risk of stroke and the device’s safety profile will be sufficient for some patients to choose this option,” wrote Andrew Farb, MD, and colleagues. “The low absolute risk of recurrent stroke, uncertainty regarding the magnitude of risk reduction, and the device-related risks will lead others to continue medical therapy. Physicians should engage in shared decision making with patients to elicit and consider their values and set reasonable expectations regarding treatment plans.”

Here’s a brief rundown of the three related studies:

PFO closure trumps antiplatelet therapy—but has risks

Lead researcher Jean-Louis Mas, MD, and colleagues conducted a randomized trial assigning 663 stroke patients, in a 1:1:1 ratio, to transcatheter PFO closure plus antiplatelet therapy, antiplatelet monotherapy or oral anticoagulation. The PFO closure and anticoagulation groups were separately compared to the patients receiving antiplatelet therapy alone.

“The five-year risk of stroke, according to the Kaplan–Meier probability estimate, was 4.9 percentage points lower with PFO closure plus antiplatelet therapy than with antiplatelet therapy alone, which would result in one stroke avoided at five years for every 20 treated patients,” Mas et al. wrote.

The researchers noted an increased risk of AFib in the PFO closure group and said the effects of oral anticoagulant therapy compared to antiplatelet therapy couldn’t be determined.

PFO closure associated with stroke risk decrease of 45 percent

In a one-to-one randomized trial of 980 adults followed for a median of 5.9 years, the risk of recurrent ischemic stroke was decreased by 45 percent in patients undergoing PFO occlusion versus those treated with medical therapy alone.

The medical therapy group was treated with aspirin, warfarin, clopidogrel, or aspirin combined with extended-release dipyridamole. The recurrent stroke risk was measured by events per 100 patient years—0.58 for the PFO closure group and 1.07 for the medical therapy group.

Lead researcher Jeffrey L. Saver, MD, and colleagues noted greater incidence of venous thromboembolism—including pulmonary embolism and deep-vein thrombosis—in the PFO closure group.

“The rate of venous thromboembolism in both groups exceeded that in healthy populations, which suggests that persons who have had a cryptogenic stroke and also have a PFO have a mildly elevated long-term risk of venous thromboemboli,” they wrote. “In our trial, the lower intensity of antithrombotic therapy, including the less common use of anticoagulant agents, in the PFO closure group than in the medical-therapy group may have contributed to the higher rate of venous thromboembolism in the PFO closure group.”

Multinational study yields similar results

Much like the other studies, research conducted by Lars Sondergaard, MD, and colleagues showed decreased risk of recurrent stroke in patients undergoing PFO occlusion.

A total of 664 patients across seven countries in North America and Europe were randomized 2:1 to receive PFO closure plus antiplatelet therapy or antiplatelet monotherapy. The mean age of the study population was 45.2, with a median follow-up of 3.2 years.

Recurrent stroke occurred in 1.4 percent of patients in the PFO closure group and 5.4 percent of patients in the antiplatelet-only group. Incidence of new brain infarction (5.7 percent vs. 11.3 percent) and serious adverse events (23.1 percent vs. 27.8 percent) was also lower in the PFO closure group.

AFib was more common in patients receiving the device, but the researchers noted it was usually transient.