Conference Coverage

Data support revising ASCVD cardiovascular risk threshold



– Revising the threshold for actionable high cardiovascular risk from the current 7.5% or greater risk of an event within 10 years as defined in American College of Cardiology/American Heart Association guidelines using the Atherosclerotic Cardiovascular Disease (ASCVD ) Risk Calculator to a 10% or greater 10-year risk would provide the optimal balance of sensitivity and specificity for discriminating future risk of cardiovascular events, according to Robert S. Rosenman, MD.

Dr. Robert S. Rosenman

Dr. Robert S. Rosenman

“I think this is very important from a public health policy perspective,” Dr. Rosenman, a cardiologist who is professor of medicine at Mount Sinai School of Medicine in New York, said at the annual congress of the European Society of Cardiology.

He elaborated: “This would eliminate 11.4 million people who are currently candidates for a statin but may not be getting the benefits of statin therapy. We feel that this information is actually quite important for the primary prevention population because there’s been a lot of pushback from our primary care physician colleagues about the overtreatment of low-risk individuals” under the current guidelines (Circulation. 2014 Jun 24;129[25 Suppl 2]:S49-73).

Dr. Rosenman and his coinvestigators conducted a secondary analysis of data on 21,343 adults in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study. All participants were free of a baseline history of heart disease or stroke. During a median 8.5 years of follow-up, 1,717 of them experienced adjudicated coronary heart disease or stroke events.

In multivariate analyses adjusted for standard cardiovascular risk factors, socioeconomic and demographic factors, and the use of statins and/or antihypertensive drugs, the higher the baseline 10-year predicted risk using the ACC/AHA ASCVD Risk Calculator based on the Pooled Cohort risk equations, the higher the incidence rate of cardiovascular events. No surprise there.

What was impressive, however, was that the optimal combination of sensitivity and specificity as captured in a statistic known as Youden’s index occurred at a 10-year predicted risk of 10%-12%. The biggest net improvement obtained through reclassification resulted from moving the threshold for elevated 10-year cardiovascular risk warranting statin therapy from 7.5% or greater to 10% or more, rather than using thresholds of 15% or 20%.

Predictive performance of different cardiovascular risk thresholds

He cited data from the 2011-2014 National Health and Nutrition Examination Survey in support of his estimate that switching to a 10% threshold from the current 7.5% threshold would reduce the number of Americans deemed at high cardiovascular risk from 57.1 million to 45.8 million.

“This cutoff value of 10%, by the way, is the same cutoff value used in the recently published ACC/AHA guideline on hypertension. And it’s also the same cutoff value used for antiplatelet therapy in looking at the benefit/risk ratio. So this value of 10% is, I think, really the right number. Our study is the first effort that has been shown to validate that number, and it brings the cutoff values in the various guidelines in line,” the cardiologist observed.

Asked if these new findings are likely to result in a revision of the ACC/AHA cardiovascular risk assessment guidelines, Dr. Rosenman replied that the guidelines are under revision, with the draft update now circulating for comment. So the timing is dicey: His study is now in prepublication peer review, but hasn’t yet been published and thus may not carry persuasive weight.

“Hopefully, the guideline panel is going to make an adjustment to make the 10% figure in line with the blood pressure guidelines,” he said.

The new analysis of the REGARDS study was funded by a collaboration between Amgen, Mount Sinai School of Medicine, and the University of Alabama. Dr. Rosenman reported receiving research funding from and serving as an advisor to Amgen and a handful of other companies.

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