Implications of the new American College of Cardiology/American Heart Association cholesterol guidelines for primary atherosclerotic cardiovascular disease event prevention in a multi ethnic cohort: Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: The impact of replacing the National Cholesterol Education Program (NCEP)/Adult Treatment Program (ATP) III cholesterol guidelines with the new 2013 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for primary prevention of cardiovascular disease is unclear.

METHODS: We used risk factor and 10-year clinical event rate data from MESA, combined with estimates of efficacy of moderate and high-intensity statin therapy from meta-analyses of statin primary prevention trials to estimate (a) the change in number of subjects eligible for drug therapy and (2) the anticipated reduction in atherosclerotic cardiovascular disease (ASCVD) events and increment in type 2 diabetes mellitus (T2DM) associated with the change in cholesterol guidelines.

RESULTS: Of the 6,814 MESA participants, 5,437 were not on statins at baseline and had complete data for analysis (mean age 61.4±10.3). Using the NCEP/ATP III guidelines, 1,334 (24.5%) would have been eligible for statin therapy compared with 3,015 (55.5%) under the new ACC/AHA guidelines. Among the subset of newly eligible, 127/1,742 (7.3%) had an ASCVD event during 10years of follow-up. Assuming 10years of moderate-intensity statin therapy, the estimated absolute reduction in ASCVD events for the newly eligible group was 2.06% (number needed to treat [NNT] 48.6) and the estimated absolute increase in T2DM was 0.90% (number needed to harm [NNH] 110.7). Assuming 10years of high-intensity statin therapy, the corresponding estimates for reductions in ASCVD and increases in T2DM were as follows: ASCVD 2.70% (NNT 37.5) and T2DM 2.60% (NNH 38.6). The estimated effects of moderate-intensity statins on 10-year risk for ASCVD and T2DM in participants eligible for statins under the NCEP/ATP III were as follows: 3.20% (NNT 31.5) and 1.06% (NNH 94.2), respectively.

CONCLUSION: Substituting the NCEP/ATP III cholesterol guidelines with the 2013 ACC/AHA cholesterol guidelines in MESA more than doubled the number of participants eligible for statin therapy. If the new ACC/AHA cholesterol guidelines are adopted and extend the primary prevention population eligible for treatment, the risk-benefit profile is much better for moderate-intensity than high-intensity statin treatment.