Stress testing in women: sexual discrimination or equal opportunity?

Impact of gender on risk stratification by stress echocardiography

OBJECTIVE

To compare the prognostic value of stress echocardiography results in men and women with known and suspected coronary artery disease.

METHODS

We analyzed the data of 8737 patients (5529 men and 3208 women) who underwent stress echocardiography (exercise in 523 patients, dipyridamole in 6227 patients, dobutamine in 1987) for evaluating known (n=3857) or suspected (n=4880) coronary artery disease. Patients were followed up for the occurrence of overall mortality or nonfatal myocardial infarction.

RESULTS

During a median follow-up of 25 months, 1218 cardiac events (693 deaths and 525 infarctions) occurred. Moreover, 2263 patients (1731 men [31%] and 532 women [17%]; P<.0001) underwent coronary revascularization and were censored. Stress echocardiography results added prognostic information to that of clinical findings and resting wall motion score index in men and women with both known and suspected coronary artery disease. In patients with known coronary artery disease, women had a higher (P=.01) event rate than men in the presence of ischemia. The annual event rate was worse for nondiabetic women (P=.007) but not diabetic women; age had a neutral prognostic effect in the 2 sexes. In patients with suspected coronary artery disease, men without ischemia had a higher (P<.0001) event rate than women. The annual event rate was worse in men aged less than 65 years (P<.0001) or more than 65 years (P=.04), and those with (P=.03) or without (P<.0001) diabetes.

CONCLUSION

Prognosis is at least comparable in men and women with ischemia and in those with coronary artery disease and no ischemia at stress echocardiography. In these clinical settings, availability for major procedures should be similar for both genders.

The Stress-Recovery Index for the risk stratification of women with typical chest pain

AIM

To prospectively assess the prognostic value of the Stress-Recovery Index (SRI) in women with typical chest pain.

METHODS

165 women without known coronary artery disease, who complained of typical chest pain, were exercise tested and prospectively followed-up for the occurrence of cardiac death and nonfatal myocardial infarction. SRI, defined as the difference in absolute values between the area of heart rate-adjusted ST-segment depression during exercise and recovery, was derived in all. Clinical data, resting ejection fraction, and exercise testing data were entered into a sequential Cox's model; SRI was entered last. Model validation was performed by bootstrap adjusted by the degree of optimism in estimates. Survival curves were set up using Kaplan-Meier method and compared by the log-rank test.

RESULTS

During a median follow-up time of 42 months, 19 events (14 cardiac deaths and 5 nonfatal myocardial infarction) were observed. Age (hazard ratio 3.58, 95% CI 0.87-15) and SRI (hazard ratio 0.62, 95% CI 0.42-0.92) were multivariate predictors of outcome. However, the addition of SRI increased the prognostic power of the model on top of clinical and exercise testing variables, as demonstrated by the significant (p=0.003) increase of the area under the ROC curve of the risk function. Survival analysis showed ascending SRI quartiles to identify a significant (p=0.005) increase in event-free survival.

CONCLUSIONS

SRI is of value in predicting outcome of women with typical chest pain and provides additional prognostic information on the top of clinical and standard exercise testing data.