No clinical risk score is universally accepted for coronary artery disease. In 603 patients (mean age, 61.2 ± 12.3 yr) with stable coronary artery disease, we investigated the predictive power of clinical risk scores derived from the Framingham, the Long-term Intervention with Pravastatin in Ischemic Disease (LIPID), and the Vienna and Ludwigshafen Coronary Artery Disease (VILCAD) studies. Secondary outcomes were the recurrence of an acute thrombotic event (coronary events, strokes, or transient ischemic attacks), or heart failure or death. The primary outcome was the combination of secondary outcomes.
During follow-up (duration, 2.08 ± 0.97 yr), 42 patients had an acute thrombotic event; 22, heart failure or death; and 60, the primary outcome.
The Framingham score predicted acute thrombotic events: hazard ratio (HR)=1.05; 95% confidence interval (CI), 1.01–1.08; P=0.03; net reclassification index (NRI, calculated to evaluate improvement in prediction gained by adding different risk scores to models constructed with variables excluded from the calculation of that score)=9.7% (95% CI, 9.6–9.8). The LIPID (HR=1.13; 95% CI, 1.04–1.22; P=0.005) and VILCAD scores (HR=1.99; 95% CI, 1.48–2.67; P <0.001) predicted heart failure or death with NRIs of 5.8% (95% CI, 5.7–5.9) and 18.6% (95% CI, 18.3–18.9), respectively. The primary outcome was predicted by the LIPID (HR=1.1; 95% CI, 1.03–1.17; P=0.005) and VILCAD scores (HR=1.39; 95% CI, 1.13–1.70; P=0.003). The NRIs (95% CIs) were 3.4% (3.3–3.5) and 19.4% (19.3–19.6), respectively.
We conclude that the accuracy of these risk scores varies in accordance with the outcome studied.
