No benefit with imaging plus exercise testing for initial CAD diagnosis in women
Level 2: Mid-level evidence
Guidelines from the American Heart Association recommend standard treadmill exercise testing of symptomatic women as an initial evaluation for suspected coronary artery disease (CAD) (Circulation. 2005;111:682-696). Exercise testing in combination with myocardial perfusion imaging (MPI) to diagnose CAD is known to have better sensitivity and specificity than standard exercise testing (Am J Cardiol. 1999;83:660-666). Despite the absence of data showing a difference in clinical outcomes, some clinicians prefer exercise testing with MPI as the initial test when evaluating women.
A randomized trial, What is the Optimal Method for Ischemic Evaluation in Women (WOMEN), investigated the value of adding MPI to exercise testing for initial diagnosis in 824 symptomatic women (Circulation. 2011;124:1239-1249). Women with typical or atypical angina (if aged 50 to 60 years) or nonanginal symptoms (if aged 60 years or older) were randomized to standard exercise treadmill test alone vs. exercise treadmill test plus MPI, and were followed for two years. The primary endpoint was incidence of major cardiac adverse events, a composite of cardiovascular mortality and hospitalization for acute coronary syndrome or heart failure.
Results were normal for 64% of initial exercise tests in the exercise-test-alone group and for 91% of MPI tests in the MPI group. Follow-up MPI testing was performed in 18% of the exercise alone group, while 9% of the MPI group had repeat MPI. In an analysis of 93.7% of the randomized women at two years, there were no significant differences in major cardiac adverse events (1.7% vs. 2.3%) or in hospitalization for chest pain (3% vs. 4%). Additionally, there were no significant differences in the rates of angina-free status at two years (60.4% vs. 64.9%, respectively).
Alan Ehrlich, MD, is a deputy editor for DynaMed, Ipswich, Mass., and assistant clinical professor in Family Medicine, University of Massachusetts Medical School in Worcester. DynaMed is a database that provides evidence-based infor-mation on more than 3,000 clinical topics and is updated daily through systematic surveillance covering more than 500 journals. The most important evidence identified is summarized here.