Acting on evidence and its absence

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 - CandaceStuart
Candace Stuart, Editor

Lack of evidence and lack of awareness of the evidence create many conundrums. We saw that play out in several ways in recent days.

This week in JAMA, researchers who analyzed data in the CathPCI registry offered insights in what falls under the lack-of-evidence category. They looked at the use of blood transfusions in PCI, a practice that some small or observational studies have indicated may hold risk for certain patients. The JAMA study added to the mounting evidence that associates transfusions with poor outcomes.

But where it broke new ground was in its assessment of practice patterns in the U.S. It showed that the rate of transfusions varied widely, with about a quarter of hospitals giving transfusions to less than 1 percent of patients and 3.7 percent of hospitals providing transfusions to more than 5 percent of patients. Hospitals in the high-transfusing group provided transfusions to all hemoglobin values more frequently than the medium and low groups.

The authors prefaced the study with the observation that guidelines on the use of transfusions in several cardiovascular settings offered cautious or no recommendations. With no concrete recommendations, physicians and hospitals are left to beliefs of what is best, which likely fuels variability. The authors made a strong case of the need for an appropriately powered randomized clinical trial of transfusion strategies to guide practice.

Another study tried to address lack of evidence, this time in the realm of CT imaging and cardiac rhythm management devices. A warning from the FDA about the potential for radiation from CT imaging to interfere with the functioning of pacemakers and implantable cardioverter-defibrillators motivated the research. The authors argued that the FDA’s notification was based on limited peer-reviewed evidence.

Based on their retrospective, observational study, CT imaging earned a reprieve. They observed no clinically significant events in an assessment of 516 CT scans on 132 ICDs and 184 permanent pacemakers—results they suggested should inform a re-evaluation by the FDA.

Physicians’ lack of awareness despite guidelines based on reasonable evidence poses another challenge. A recent analysis found about one in five patients who met the criteria for ACEI/ARB therapy did not receive it. In an interview, Deepak L. Bhatt, MD, MPH, of Brigham and Women’s Hospital Heart and Vascular Center in Boston, said that physicians often initiate ACEI/ARB treatment in patients admitted with heart failure, but not in patients with acute coronary syndrome, “which is an awareness issue.”

Recognizing when healthcare professionals lack sufficient evidence to make appropriate decisions or when they fail to integrate peer-reviewed guideline recommendations into practice will help improve patient care. So please spread the word and help get the message out.

Candace Stuart

Cardiovascular Business, editor

cstuart@cardiovascularbusiness.com