PFO Research Suggests Closure Not Indicated in Cryptogenic Stroke or TIA.

Controversial research has suggested for years closing a patent foramen ovale (PFO) may offer no benefit in stroke patients.  PFOs are small holes in the heart, most commonly the result of benign embryonic development. Upwards of 25% of the population have them and don't even know it.    Through the years, physicians have routinely recommended an invasive cardiovascular approach to close these benign holes in the heart.  Doing so was thought to reduce the risk (secondary prevention) of recurrent stroke or transient ischemic attack (TIA) in cryptogenic stroke (strokes with no alternative explanation).

PFO closure is currently considered an investigational procedure by the FDA, although many patients are treated off label with closure devices.  So the question that must be asked is, does PFO research suggest closure is indicated in the secondary prevention of cryptogenic stroke or TIA or are we doing invasive procedures that carry risk and a great deal of expense without any benefit to our patients at large?

The New England Journal of Medicine is reporting on new research that suggests PFO closure has no place in the medical or invasive therapies for cryptogenic stroke patients and some are suggesting PFO closure should only be performed in the setting of investigational studies.  The study enrolled 909 patients (between 18 and 60 years old)  into  a multicenter, randomized, open-label trial of closure with a percutaneous device or medical therapy (warfarin, aspirin or both) alone participants.  Patients qualified by having  had a TIA or ischemic stroke within the previous six months and evidence of PFO with shunt by bubble study on trans-esophageal echo. Patients were excluded if an alternative cause could explain the TIA or stroke.  Cross overs were not permitted.  

The primary end point of the study was stroke or TIA during 2 years of follow-up, death from any cause in the first 30 days and death from neurological cause between 31 days and 2 years.  Secondary end points included major bleeding, death from any cause, stroke, TIA and transient neurological events of uncertain cause.    What did this PFO research suggest?  At 2 years, there was no significant difference between the  PFO closure arm and the medical therapy arm for the primary end points of recurrent stroke or TIA.   However, the major specific vascular procedural complication rate for patients in the PFO closure arm was 3.2% (13 patients) and atrial fibrillation was significantly more common in the closure group (23 patients vs 3 patients).

The study did admit that PFO closure could not be excluded as having benefit in a highly selected population.  They did not address or define what this population would be.   They also stated the study was not powered (too small a study population) to detect a smaller end point reduction of primary events (less than 2/3 reduction).    In my nearly ten years of hospitalist medicine, I cannot say I have ever had a patient in which performing a cardiac  echo if they had a normal physical exam and a normal appearing EKG and normal cardiac telemetry monitoring has ever changed my management plan. 

So why are many hospitalists and internists and family medicine doctors and neurologists ordering cardiac echos by default on this patient population who presents with stroke or TIA?  I have never found a cardiac myxoma although I have rarely  found a valvular issue to explain the stroke. I have never found a visible left atrial thrombus on a patient in sinus rhythm.

Is it a liability issue? If that's the case, I would argue that doing an echo to look for PFO that results in medically unnecessary PFO closure that results in a 3.2% rate of vascular complication and a much higher rate of atrial fibrillation offers more liability than not doing the echo at all.  Is it a standard of care issue?  If so, then why is it?  Where is the data to suggest cardiac echo in this population offers benefit?  

Is it to look for a PFO?   If that's the case, then we should stop.  Is it a matter of habit?  That's not an excuse.  That's reflex medicine.    Is it just how things are done?  Again, not an excuse.  With hospital profit margins from Medicare in the toilet and ObamaCare promising to shut down hospitals by the hundreds, perhaps thousands in the next decade, as physicians (and hospitalists that only work in hospitals), I think we have an obligation to provide cost effective care based on what is probable not what is possible.   Everything is possible if we assume extreme physiology in all cases.  We don't do a bone marrow biopsy on everyone who presents with anemia.  Why do we do an echo on everyone who presents with a TIA or stroke and a normal cardiac exam.  This PFO research suggests we cannot use PFO evaluation as an excuse anymore.  We need to stop doing echos on patients with normal cardiac exams.  It's the right thing to do.  

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