In an era of inexpensive statins, treating all Americans in the U.S. who are at intermediate risk of coronary heart disease (CHD) with statins (men and women) and aspirin (men only) is effective and less expensive than stress testing and treating only those patients with a positive result, according to a simulation study published online Dec. 5 of Circulation.
Benjamin Z. Galper, MD, MPH, of the cardiovascular division at Brigham and Women’s Hospital in Boston, and colleagues explored how the introduction of generic, high-potency statins such as atorvastatin might affect costs and outcomes for patients who are at intermediate risk (that is, a 10 to 20 percent 10-year risk) of CHD. They noted that a strategy using lipid-lowering drugs and aspirin has been effective in high-risk patients, but that it was less clear how physicians should approach the larger population of intermediate-risk patients.
Non-invasive stress testing has helped improve risk stratification by identifying patients at risk, and in some cases, motivating them to adhere to a regime of statins for women and statins and aspirin for men. Studies have shown that the addition of aspirin benefits men but not women.
They applied a computer model, the CHD Policy Model, to simulate different scenarios of drug and imaging strategies on adults in the U.S. who are at intermediate risk of CHD. They compared three strategies: a “treat-all” approach in which all men and women received statins, and for men, the addition of aspirin; a “test-and-treat” strategy that used stress testing to guide who should get medical treatment; and an Adult Treatment Panel III guideline-based strategy that called for a low-intensity statin therapy for low density lipoprotein (LDL) readings of at least 130mg/dl.
The “test-and-treat” strategy was further refined for analyses using stress EKG alone, stress EKG plus nuclear perfusion scans and stress echocardiography alone. They also ran a status quo test to capture current practice in the U.S.
The model included 22.5 million asymptomatic, intermediate-risk adult patients in a simulation that covered a 30-year period. The analysis placed the treat-all group at 368 million person-years of statin treatment and 164 million person-years of aspirin treatment. By contrast, the test-and-treat group had 62 million person-years of statin therapy and 32 million person-years of aspirin therapy. But the latter group also underwent 40.4 million stress tests, with slightly more than a fifth being positive. Stress EKG alone was the least expensive testing method.
Treat-all proved to be the least expensive and most effective option. But if a positive stress EKG resulted in medication adherence above 75 percent and treat-all adherence dropped below 22 percent, a test-and-treat approach became the preferred approach. Also, if EKG testing targeted to non-adherent patients led to at least 13 percent of them following medical orders, then it was more cost effective than the treat-all strategy.
“Our analysis suggests that the advent of low-cost statins will make treating all intermediate-risk persons, regardless of LDL level, a cost-effective primary CHD prevention strategy,” Galper and colleagues wrote. “Although ‘treat-all’ places more people on statin and aspirin therapy, it is less expensive than any other strategy because it reduces incident CHD by over one million cases over the 30-year period evaluated compared with ATP III, which was the next most effective strategy.”