Systematic review highlights treatments to reduce the risk of atherosclerotic cardiovascular disease

An overview of 35 systematic reviews of randomized clinical trials found that aspirin, blood pressure-lowering therapies and statins reduced the risk of primary atherosclerotic cardiovascular disease by 10 percent to 25 percent in adults without prevalent atherosclerotic cardiovascular disease.

Meanwhile, blood pressure-lowering therapy and statins reduced the risk for all-cause mortality by 11 percent and 14 percent, respectively. Further, tobacco cessation drugs increased the odds of continued smoking abstinence by 88 percent to 188 percent.

Lead researcher Kunal N. Karmali, MD, MS, of Northwestern University’s Feinberg School of Medicine in Chicago, and colleagues published their results online in JAMA Cardiology on April 27.

The researchers mentioned that the U.S. Department of Health and Human Services launched the Million Hearts initiative in 2011 with the goal of preventing one million heart attacks and strokes in the next five years. Million Hearts has a slogan called “ABCs” that refers to aspirin for high-risk patients, blood pressure control, cholesterol level management and smoking cessation.

This year, the Center for Medicare & Medicaid Innovation launched the Million Hearts Cardiovascular Risk Reduction Model, a cluster- randomized payment model that evaluates the use of value-based payments for atherosclerotic cardiovascular disease risk assessment and reduction.

For this analysis, the researchers evaluated systematic reviews of randomized and quasi-randomized trials that compared aspirin, blood pressure-lowering therapy, statins or tobacco cessation drugs with placebo or usual care in adults who did not have atherosclerotic cardiovascular disease.

Of the 35 systematic reviews that met the inclusion criteria, 15 evaluated the effect of aspirin, four evaluated blood pressure-lowering therapy, 12 reviewed statins and four reviewed tobacco cessation drugs in a primary prevention setting. All of the reviews were published from Jan. 1, 2005, to June 17, 2015.

For aspirin, the researchers rated the quality of evidence on all-cause mortality as moderate; on reducing major cardiovascular events as high; and on increasing major bleeding events as high.

For blood pressure-lowering therapy, they rated the quality of evidence on reducing all-cause mortality, coronary heart disease and stroke as high; and on treatment withdrawals as low.

For statins, they rated the quality of evidence on reducing the risk for all-cause mortality, major cardiovascular events, coronary heart disease events and stroke as high; and their safety as moderate.

They rated the quality of evidence for the effect of varenicline on smoking cessation as high and the effect of bupropion and nicotine replacement therapy as moderate. Further, they rated the quality of evidence for the safety of tobacco cessation drugs as moderate and their effect on all-cause mortality and cardiovascular outcomes as low.

The researchers cited a few limitations of the study, including that they did not analyze data from the primary trials and relied on the authors of the systematic reviews. They also had limited data on the safety of blood pressure-lowering therapy and tobacco cessation drugs and did not have much information on the potential of differential treatment effects by race and ethnicity. In addition, they did not have information on the added effects of diet, exercise, weight loss and other lifestyle interventions that could be combined with drug therapy.

“The overview provides reliable, evidence-based pooled estimates for these interventions on the lowered risk for primary [atherosclerotic cardiovascular disease] events and best-available evidence for the effect of tobacco cessation drugs on continuous abstinence at 6 months,” the researchers wrote. “These treatment effects can be used to enrich discussions between health care professionals and patients.”