Sudden Cardiac Death in Women With Suspected Ischemic Heart Disease, Preserved Ejection Fraction, and No Obstructive Coronary Artery Disease: A Report From the Women's Ischemia Syndrome Evaluation Study

Background-Sudden cardiac death (SCD) is often the first presentation of ischemic heart disease; however, there is limited information on SCD among women with and without obstructive coronary artery disease (CAD). We evaluated SCD incidence in the WISE (Women's Ischemia Syndrome Evaluation) study. Methods and Results-Overall, 904 women with suspected ischemic heart disease with preserved ejection fraction and core laboratory coronary angiography were followed for outcomes. In case of death, a death certificate and/or a physician or family narrative of the circumstances of death was obtained. A clinical events committee rated all deaths as cardiovascular or noncardiovascular and as SCD or non-SCD. In total, 96 women (11%) died over a median of 6 years (maximum: 8 years). Among 65 cardiovascular deaths, 42% were SCD. Mortality per 1000 person-hours increased linearly with CAD severity (no CAD: 5.8; minimal: 15.9; obstructive: 38.6; P< 0.0001). However, the proportion of SCD was similar across CAD severity: 40%, 58%, and 38% for no, minimal, and obstructive CAD subgroups, respectively (P value not significant). In addition to traditional risk factors (age, diabetes mellitus, smoking), a history of depression (P = 0.018) and longer corrected QT interval (P = 0.023) were independent SCD predictors in the entire cohort. Corrected QT interval was an independent predictor of SCD in women without obstructive CAD (P = 0.033). Conclusions-SCD contributes substantially to mortality in women with and without obstructive CAD. Corrected QT interval is the single independent SCD risk factor in women without obstructive CAD. In addition to management of traditional risk factors, these data indicate that further investigation should address mechanistic understanding and interventions targeting depression and corrected QT interval in women.