Sounding the alarm
Robert Bonow, MD, a professor of cardiology at Northwestern University in Chicago and a writing committee member for the 2014 guideline update, said the study is a “big wake-up call” and “the take-home message is that we are missing some patients who have treatable aortic stenosis.”
Dr. Robert O. Bonow
The sheer magnitude of the problem, however, can be difficult to fully ascertain from administrative data like this, he said. Notably, patients who did not receive AVR were significantly older, with 37% aged 81-90 years and 12% over age 90, and had a lower hematocrit and lower estimated glomerular filtration rate. But it’s not clear how many had cancer, end-stage renal disease, or severe lung disease, which could have factored into the decision to undergo AVR.
“What’s also an issue is that over 50% of patients had low gradient disease, which is very problematic and takes careful assessment in an individual patient,” said Dr. Bonow, who is also editor-in-chief of JAMA Cardiology. “That’s all being generated by a low valve area of less than 1 cm2 from echo reports, so that’s not necessarily a careful prospective echo assessment ... so some of the patients with low-gradient disease may not have true severe aortic stenosis.”
Dr. Elmariah agreed that echocardiogram reports are not always clear cut and pointed out that referral to a valve specialist was highly predictive of whether or not a patient underwent AVR, supporting the class 1 guideline recommendation.
He also noted that Mass General is launching the DETECT-AS trial to determine whether electronic physician notifications highlighting clinical practice guideline recommendations will improve AVR utilization over standard care in 940 patients with severe AS on echocardiogram, defined by a valve area less than 1 cm2.
Reached for comment, Catherine Otto, MD, director of the Heart Valve Clinic at the University of Washington, Seattle, and a fellow member of the 2014 guideline writing committee, said “this adds to the data [that] we’re undertreating severe aortic stenosis, and it continues to be surprising given the availability of transcatheter options.”
Dr. Catherine M. Otto
The biggest challenge is trying to find out why it persists, which is difficult to determine from these data, she said. Whether that’s because the diagnosis is being missed or whether there are barriers to access because cardiologists aren’t understanding the indications or patients aren’t understanding what’s being offered, isn’t clear.
“The other [issue], of course, is are there inappropriate inequities in care? Is it fewer women, age-related, ethnic/racial-related; is it financial? Do people have coverage to get the treatment they need in our country?” Dr. Otto said. “All of those issues are areas that need to be addressed, and I think that is a concern we all have.”
An accompanying editorial points out that the “key lever” in combating undertreatment of AS is getting patients seen by a multidisciplinary heart team and details other possible solutions, such as adding process metrics regarding evaluation and treatment of AS to hospital performance.
“We track quality when AVR is performed (desirable), but how a hospital system performs in getting individuals treated who would benefit from AVR remains a complete blind spot,” write Brian Lindman, MD, MSc, and Angela Lowenstern, MD, MHS, both of Vanderbilt University Medical Center, Nashville, Tenn.
“Is it appropriate to consider the hospital ‘high performing’ when data from Li et al. show a 2-year absolute mortality difference from 9% to 56% based on treatment versus nontreatment with AVR for various AS patient subgroups?” they add.
Dr. Lindman and Dr. Lowenstern observe that having a 50% utilization rate for an effective therapy for a deadly cancer or stenting of ST-segment elevation myocardial infarction (STEMI) would generate negative headlines and a collective commitment to swift action by multiple stakeholders to address what would be “incontrovertibly unacceptable.”
“In one of America’s leading health care systems, there was evidence of an overwhelming reduction in the risk of death with AVR in all AS subgroups examined, but <50% of patients with AS with an indication or potential indication for AVR were treated with an AVR. Let that set in; hear and internalize the alarm. The status quo is unacceptable. What will you do? What will we do?” they conclude.
The study was funded by Edwards Lifesciences. Dr. Elmariah has received research grants from the American Heart Association, National Institutes of Health, Edwards Lifesciences, Svelte Medical, Abbott Vascular, and Medtronic, and has received consulting fees from Edwards Lifesciences. Dr. Bonow and Dr. Otto have disclosed no relevant financial relationships. Dr. Lindman has received investigator-initiated research grants from Edwards. Dr. Lowenstern has received consulting fees from Edwards.
A version of this article first appeared on Medscape.com.