The interaction of gender and clinical risk profile in patients referred for exercise nuclear imaging versus exercise echocardiography.

BACKGROUND

Exercise myocardial perfusion imaging (E-MPI) and exercise echocardiography (E-Echo) are thought to be compatible for the non-invasive evaluation of patients with suspected coronary artery disease (CAD). The interaction of gender and clinical risk profile in the referral of patients to either of these two imaging modalities has not been well studied.

METHODS AND RESULTS

This was a prospective study of 922 consecutive patients who were referred for either E-MPI (331 patients) or E-Echo (591 patients) at the American University of Beirut Medical Center in the year of 2008. Men undergoing E-MPI had a higher risk profile than those undergoing E-Echo. They were older (58±12 years versus 55±12 years, p=0.002) and had a higher prevalence of multiple (>2) CAD risk factors (55% versus 37%, p<0.001) as well as a higher prevalence of prior PCI (22% versus 15%, p=0.017) or CABG (12% versus 7%, p=0.016). Furthermore, they achieved lower METS in their exercise (9.4±2.0 versus 10.4±2.3, p<0.001) and had a higher incidence of ischemia and on their scans (16% versus 9.1%, p=0.008). In contrast, women undergoing E-MPI had a similar profile to those undergoing E-Echo in terms of prevalence of risk factors, prior history of coronary events and the prevalence of ischemia or impaired ejection fraction on their scans.

CONCLUSION

There is an important interaction between gender and clinical risk profile in patients undergoing E-MPI versus E-Echo. In men, E-MPI seems to be the preferred test for the higher risk profile patients, whereas in women the two tests are interchangeable.