Sachin M. Navare

Acute cardiovascular response to exercise and its implications for exercise testing.

ConclusionExercise remains the preferred stress testing modality for patients because of its ability to provide more information than that obtained from the presence or absence of ischemia alone. A basic knowledge of the acute cardiac response to exercise can help us to obtain the greatest amount of information from this remarkably simple testing modality.

816-2 Risk stratification of diabetic patients with rest/stress ECG-gated Tc-99m sestamibi SPECT imaging: Significance of mild perfusion abnormalities

Background: The utility of screening asymptomatic diabetic patients for coronary artery disease (CAD) has not been defined. The objective of the current study was to evaluate the impact of a strategy employing screening stress myocardial perfusion imaging (MPI) on short-term prognosis in diabetic patients without symptoms or known CAD, who otherwise had no indication for stress MPI. Methods: Asymptomatic diabetic males were enrolled in a strategy of screening stress MPI. All patients underwent routine MPI after exercise or dipyridamole stress using standard protocols, and were followed clinically for cardiac events (cardiac death, myocardial infarction, coronary angiography and revascularization). The Framingham global risk assessment score was used to for comparison of risk factors and to estimate the pre-test likelihood of CAD among patients. Results: In 44 asymptomatic diabetic males (age 66±8 years) without known CAD, 20 (45%) had an abnormal stress MPI (9 mildly abnormal, 11 moderately/severely abnormal). During short-term follow-up (18+3 months), there were no major adverse cardiac events in 33 patients with a normal or mildly abnormal stress MPI. Of 11 patients with a moderately/ severely abnormal MPI, 7 were subsequently referred for coronary angiography. All 7 had significant CAD (6 with left main coronary artery and/or 3-vessel CAD), and 5 of these patients required revascularization (4 surgical). The Framingham global risk profile score for CAD in patients with a normal/ mildly abnormal MPI was similar to those with a moderate/severely abnormal stress MPI (9.7±2.6 vs. 9.8±2.2, respectively, p=NS). Conclusion: A strategy of screening asymptomatic diabetics for CAD with stress MPI may be justified for additional risk stratification beyond clinical assessment. Patients with a normal or mildly abnormal stress MPI have a favorable prognosis, while those with a moderately/severely abnormal study (25% in this population) have a high incidence of severe CAD that may warrant assessment with angiography.