Improving the positive predictive value of exercise testing in women.

OBJECTIVE To identify exercise test variables that can improve the positive predictive value of exercise testing in women. DESIGN Cohort study. SETTING Regional cardiothoracic centre. SUBJECTS 1286 women and 1801 men referred by primary care physicians to a rapid access chest pain clinic, of whom 160 women and 406 men had ST depression of at least 1 mm during exercise testing. The results for 136 women and 124 men with positive exercise tests were analysed. MAIN OUTCOME MEASURES The proportion of women with a positive exercise test who could be identified as being at low risk for prognostic coronary heart disease and the resulting improvement in the positive predictive value. RESULTS Independently of age, an exercise time of more than six minutes, a maximum heart rate of more than 150 beats/min, and an ST recovery time of less than one minute were the variables that best identified women at low risk. One to three of these variables identified between 11.8% and 41.2% of women as being at low risk, with a risk for prognostic disease of between 0-11.5%. The positive predictive value for the remaining women was improved from 47.8% up to 61.5%, and the number of normal angiograms was potentially reducible by between 21.1-54.9%. By the same criteria, men had higher risks for prognostic disease. CONCLUSIONS A strategy of discriminating true from false positive exercise tests is worthwhile in women but less successful in men.