BACKGROUND: Women are more likely than men to have nonspecific chest pain (NSCP) symptoms. The long-term outcomes in women discharged with a diagnosis of NSCP are unknown.

METHODS: The Women's Health Initiative Observational Study enrolled postmenopausal women aged 50-79 years. After excluding those with prior cardiovascular disease (CVD), 83,622 women were studied. NSCP cases were defined as having an initial primary hospital discharge diagnosis of NSCP (ICD-9 codes 786.50, 786.51, 786.59) without a prior diagnosis of coronary heart disease (CHD). Risks of subsequent CHD events were estimated from Cox proportional hazard ratio (HR) models stratified by clinic and adjusted for baseline age, cardiovascular risk factors, and hormone use.

RESULTS: Over an average of 8 years of follow-up, 11% (230 of 2,092) of women with NSCP experienced a cardiovascular event compared with 9.5% (7,724 of 81,530) who did not. Compared with women without a hospitalization for NSCP during follow-up, those with NSCP had a greater than 2-fold higher risk of a subsequent hospitalization for clinically diagnosed angina (HR 2.18, 95% CI 1.66-2.86) and at least a 1.5-fold higher risk of nonfatal myocardial infarction (MI) (HR 1.59, 1.10-2.31), revascularization (HR 1.67, 1.28-2.20), and congestive heart failure (HR 1.75, 1.27-2.41). Women with NSCP who subsequently experienced a CHD event were more likely to be over age 65 or to have cardiovascular risk factors.

CONCLUSIONS: Older women discharged with a diagnosis of NSCP may be at increased risk of CHD morbidity. Further research is needed to replicate these findings in other populations.