Abstract 2182: Stroke and TIA as CHD Risk Equivalents: Findings From the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Study
Introduction: In SPARCL, atorvastatin reduced the risk of stroke by 16% (hazard ratio [HR] 0.84, 95% confidence interval [CI] 0.71 to 0.99, p=0.03) in patients with non-cardioembolic stroke and no known coronary heart disease (CHD). Non-coronary forms of atherosclerosis including carotid artery disease (transient ischemic attacks [TIA] or stroke of carotid origin, or greater than 50% stenosis of the carotid artery) are recognized equivalents to CHD as defined by a 10-year vascular risk of 20%. SPARCL provides an opportunity to evaluate the risk of developing clinically recognized CHD in these patients.
Methods: In SPARCL, 4731 stroke/TIA patients (mean age 63 years) with no known CHD were randomized to atorvastatin 80 mg/day or placebo and followed for a median of 4.9 years. The CHD risk of patients randomized to placebo was calculated and the impact of atorvastatin was evaluated.
Results: Mean baseline LDL-C was 133 mg/dL and mean on-treatment LDL-C was 72.9 mg/dL for atorvastatin and 128.5 mg/dL for placebo. Only 16% of placebo treated patients in SPARCL had large vessel atherothromboembolic stroke as an entry event, falling under current guidelines for cholesterol management. The CHD event rate was 1.9%/person/year and the major coronary event rate was 1.1%/person/year in the placebo-treated patients, or 19% and 11% projected over 10 years, respectively (independent of time between entry event and randomization), despite concomitant treatment with antiplatelet (94.1%) and antihypertensive (69.2%) therapies. Moreover, 25.4% of placebo patients received non-study statin therapy. Atorvastatin significantly reduced the risk of CHD events by 42% (HR 0.58, 95% CI, 0.46 to 0.73, p<0.001) and major coronary events by 35% (HR 0.65, 95% CI, 0.49 to 0.87, p=0.003).
Conclusions: Non-cardioembolic stroke is a CHD risk equivalent regardless of the underlying etiology and this risk can be substantially reduced by atorvastatin therapy.