Percutaneous PFO closure following cryptogenic stroke or TIA appears effective and carries low risks of minor and major complications in the years after treatment, according to a retrospective study published online June 23, 2015, ahead of print in Catheterization and Cardiovascular Interventions.  

“Our study demonstrates that percutaneous PFO closure in patients with presumed paradoxical embolism is safe and effective,” write Mikaeil Mirzaali, BMBS, of Brighton and Sussex University Hospitals (Brighton, England), and colleagues.   

The researchers examined data on 301 patients (mean age 48.6 years; 54.4% men) with a history of at least 1 neurovascular event who underwent PFO closure at their institution between May 2004 and January 2013. Mortality data were collected from the Medical Research Information Service and details regarding stroke or TIA recurrence were obtained via mailed questionnaires as well as medical and imaging records.

The reason for closure was stroke in 64.8% of patients, TIA in 32.2%, and peripheral embolism in 3.0%. Eight different PFO closure devices were used in the cases, and successful implantation occurred in 99% of patients.

Procedural guidance with fluoroscopy alone or in addition to intracardiac echocardiography, TEE, or transthoracic echocardiography was used in 42.2%, 46.2%, 10.0%, and 1.6% of patients, respectively. Mean procedure time was 39.2 minutes, and 49.7% of patients were discharged on the same day.  

Minimal Minor, Major Complications

Due to persistent right-to-left shunting (n = 2), device failure (n = 1), and an inadequate seal (n = 1), 4 patients required a second procedure. Minor periprocedural complications—device removal and replacement, transient ST elevation, or sustained arrhythmia—were experienced by 8 patients.

Over a mean follow-up period of 40.2 months (range 1.3-105.3 months), 2 patients died from unrelated causes, 9 had a TIA (0.98 per 100 person-years), 5 had a stroke (0.55 per 100 person-years), and 14 were treated for A-fib (1.55 per 100 person-years). The combined rate of recurrent stroke and TIA was 1.53 cases per 100 person-years.

PFO Closure Debate Not Settled  

There are currently 3 methods for preventing subsequent cryptogenic stroke in patients with PFOs: surgical closure, percutaneous closure, and medical therapy with antiplatelet or anticoagulant agents, the study authors say.

Though surgical PFO closure appears effective at reducing secondary stroke and TIA, it carries the serious risks of bleeding, tamponade, and infection, all resulting in high morbidity, they explain. With medical therapy, the researchers report, the estimated rate of recurrent stroke is 1.73 cases per 100 person-years and 3.19% for combined TIA and stroke. 

Percutaneous closure and medical therapy have been compared in 3 randomized controlled trials—RESPECT, the PC-Trial, and CLOSURE I—each of which found no reductions in subsequent TIA and stroke with PFO closure .

However, Dr. Mirzaali and colleagues write that “the patients in the clinical trials appeared to be a lower-risk cohort than those undergoing closure in previous studies,” possibly resulting in lower event rates. Additionally, the 3 trials “concluded that an alternative explanation unrelated to paradoxical embolism is present in 80% of patients with recurrent stroke or TIA,” they say.

The investigators call for better standardized evaluation that could discern alternate causes of cryptogenic stroke, thereby enabling additional studies to assess PFO closure in patients most likely to benefit.

Because TIA is a “less-precise endpoint” than stroke, they also suggest that larger studies in the future might consider evaluating stroke as the only endpoint.

The authors acknowledge several limitations to their study. Because the diagnosis of PFO-mediated paradoxical embolism was presumptive, PFO and cryptogenic stroke may have coexisted without causal relation in certain patients, they say. There also may be underrepresentation of adverse events, as 18 patients were lost to follow-up. In addition, some silent embolic events or paroxysmal untreated A-fib may have been unreported by patients.

Mirzaali M, Dooley M, Wynne D, et al. Patent foramen ovale closure following cryptogenic stroke or transient ischaemic attack: long-term follow-up of 301 cases. Catheter Cardiovasc Interv. 2015;Epub ahead of print. 

Disclosure:

• Dr. Mirzaali reports no relevant conflicts of interest. 

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