AcuteCare Telemedicine Blog


Two Steps Forward, Two Steps Back

Sometimes, moving healthcare forward is achieved simply by looking back. The following article illustrates the latest example of the type of discoveries that fuel the constant evolution of medicine. Modern techniques, such as those utilized in telemedicine practices, often rely on the latest technical and innovative advances, but stepping back and evaluating standard procedures is a crucial step in ensuring the highest possible standards of care. As in the case of the findings featured here, discarding methods once thought to be best practices can improve both patient outcomes and cost-efficiency.

No Benefit to Patent Foramen Ovale (PFO) Closure in Ischemic Stroke or TIA

S. Andrew Josephson 

M.D., Department of Neurology, University of California San Francisco, San Francisco, USA

 Between 25% and 40% of ischemic strokes have no clear cause despite extensive investigation. These “cryptogenic” strokes may in some instances be due to an embolus traveling through a right-to-left shunt in the heart. A patent foramen ovale (PFO) is present in nearly one-quarter of patients in autopsy studies and is even more prevalent in young patients with cryptogenic stroke. Whether these PFOs should be treated with medical therapy or closure remains a point of much debate; Furlan and colleagues (2012) examined the benefit of a percutaneous closure device for preventing further cerebrovascular events in patients with cryptogenic stroke and transient ischemic attack (TIA).

The authors enrolled patients between the ages of 18 and 60 who had experienced a cryptogenic stroke or TIA within the previous 6 months and who were found to have a PFO documented by transesophageal echocardiography (TEE) with bubble study. These patients were randomly assigned either to percutaneous closure with the STARFlex device plus antiplatelet therapy or to medical therapy alone. Those assigned to closure were treated with clopidogrel for 6 months and aspirin for 2 years, whereas those assigned to medical therapy were treated with warfarin, aspirin, or both at the discretion of the site investigator. The primary outcome examined was a composite 2-year rate of stroke or TIA, death from any cause in the first 30 days, or death from a neurologic cause from 31 days to 2 years.

The authors enrolled 909 patients in the trial, and there were no significant differences in the baseline characteristics of the two groups. At 6 months, effective closure was confirmed by TEE in 86% of the closure group. The primary endpoint was reached in 5.5% of the closure group and 6.8% of the medical group (hazard ratio, 0.78; 95% confidence interval, 0.45–1.35; p = .37). There were no significant differences in stroke or TIA rates between the two groups, although the latter TIA endpoint (a “softer” endpoint, subject to patient reporting) was numerically higher in the medical therapy group. There were no differences in adverse events between the two groups. Atrial fibrillation more frequently developed in the closure group compared with the medical group (5.7% vs 0.7%; p < .001). A variety of subgroups were examined, including sex, the presence of an atrial septal aneurysm, shunt size, entry event (stroke vs TIA), and baseline medication; none was found to significantly favor percutaneous closure.

This well-done negative trial definitively demonstrates no benefit to PFO closure in patients with cryptogenic stroke and argues strongly that these patients should either be treated with medical therapy or be invited to participate in ongoing randomized trials of different devices. The slow recruitment in this trial, which began enrolling in 2003, was likely due in part to the fact that the device was available for use outside of the trial and many patients and their physicians chose to close PFOs rather than enrolling in the study. One limitation of this study may therefore have been a bias toward patients with characteristics thought by their physicians to warrant randomization, perhaps those at perceived at lower risk for stroke. Ideally, the definitive results of this trial will mean that percutaneous PFO closure no longer is practiced outside of these trials.

– Josephson, SA. No Benefit to Patent Foramen Ovale (PFO) Closure in Ischemic Stroke or TIA. Harrison’s Online, April 23, 2012. http://www.accessmedicine.com

Related to Chapter 370 Cerebrovascular Diseases in Harrison’s Principles of Internal Medicine, 18thedition, Dan L. Longo, Dennis L. Kasper, J. Larry Jameson, Anthony S. Fauci, Stephen L. Hauser, Joseph Loscalzo, Eds. McGraw-Hill, New York, 2012.

Reference

Furlan AJ et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med 2012;366:991.

Understanding that even the most accepted methods of diagnosis and treatment are subject to scrutiny is a key tenet of the relentless pursuit of a better standard of care. The partners of AcuteCare Telemedicine agree with Dr. Furlan’s recommendation that device closure of PFOs should now be limited to patients enrolled in one of the ongoing trials.


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