Results:

The enrolled 2,904 women were generally older and more often obese, whereas men had a greater prevalence of known CAD including more often prior revascularization. More than one half of the 3,133 men had a high pretest CAD likelihood, whereas approximately one third of women were at low pretest CAD likelihood. Five-year CAD mortality was 3.7% for women and 6.0% for men (p < 0.0001). Unadjusted CAD mortality ranged from 0.9% to 12.9% for women (p < 0.0001) and from to 1.5% to 17.4% for men (p < 0.0001) for 0% to ≥15% abnormal myocardium at stress. In multivariable models, the % abnormal stress myocardium was independently predictive of CAD mortality in women and men. An interaction term of gender by % abnormal stress myocardium was nonsignificant (p = 0.39). The categorical net reclassification improvement index (NRI) when Rb-82 PET data were added to a clinical risk model was 0.12 for women and 0.17 for men. Only two cardiac deaths were reported in women <55 years of age; accordingly, the % abnormal myocardium at stress was of borderline significance (p = 0.063), but was highly significant for women ≥55 years of age (p < 0.0001) with an increased NRI of 0.21 (0.09-0.34), including 17% of CAD deaths and 3.9% of CAD survivors correctly reclassified.