Objective: To assess the prognostic significance of stress echocardiography in women with a high probability of coronary artery disease (CAD).
Setting: Secondary and tertiary cardiology unit at a university teaching hospital.
Participants: A total of 135 women (mean (SD) age 63 (9) years) with pre-test probability of CAD > or = 80% were selected from a database of patients investigated by treadmill or dobutamine stress echocardiography between 1995 and 1998.
Main outcome measures: Patients were followed up for occurrence of subsequent cardiac events (cardiac death, myocardial infarction, admission with unstable angina, and revascularisation) using a structured telephone interview and case note review.
Results: Each patient had between two and seven (mean 3.5) CAD risk factors and pre-test probability of CAD > or = 80%. Ninety three patients (68.9%) had negative stress echocardiography. Mean (SD) follow up was 20.1 (8.5) months. There were six events in the positive stress echocardiography group (two cardiac deaths, one unstable angina, three revascularisations), and one event in the negative stress echocardiography group. Cox regression analysis showed positive stress echocardiography (p = 0.02) and age (p = 0.03) to be the only univariate predictors and positive stress echocardiography to be the only independent predictor of future cardiac events (relative risk 8.9, confidence interval 1.0 to 76.5, p = 0.04). Cumulative event free survival to 38 months was 98% in the negative stress echocardiography and 50.7% in the positive stress echocardiography groups.
Conclusion: In women with high pre-test likelihood of CAD: (1) negative stress echocardiography identifies a subgroup with low risk of cardiac events who do not require further invasive investigation and (2) positive stress echocardiography identifies a subgroup with increased risk of subsequent cardiac events.