OBJECTIVE: Exercise tolerance in patients with diabetes is frequently
impaired due to noncardiac disease such as claudication and
polyneuropathy. This study assesses the prognostic value of dobutamine
stress myocardial perfusion imaging in patients with diabetes. RESEARCH
DESIGN AND METHODS: A total of 207 consecutive diabetic patients who were
unable to undergo exercise stress testing underwent dobutamine-atropine
stress myocardial perfusion imaging. Follow-up was successful in 206 of
207 (99.5%) patients. A total of 12 patients underwent early (<60 days)
revascularization and were excluded from the analysis. End points during
follow-up were hard cardiac events, defined as cardiac death and nonfatal
myocardial infarction. RESULTS: Abnormal myocardial perfusion was detected
in 125 (64%) patients. During 4.1 +/- 2.4 years of follow-up, 73 (38%)
deaths occurred, 36 (49%) of which were due to cardiac causes. Nonfatal
myocardial infarction occurred in 7 (4%) patients, and 45 (23%) patients
underwent late coronary revascularization. Cardiac death occurred in 2 of
69 (3%) patients with normal myocardial perfusion and in 34 of 125 (27%)
patients with perfusion abnormalities (P < 0.0001). A multivariable Cox
proportional hazard model demonstrated that, in addition to clinical and
stress test data, an abnormal scan had an incremental prognostic value for
prediction of cardiac death (hazard ratio 7.2, 95% CI 1.7-30). The summed
stress score was an important predictor of cardiac death; the hazard ratio
was 1.2 (95% CI 1.07-1.34) per one-unit increment. CONCLUSIONS:
Dobutamine-atropine stress myocardial perfusion imaging provides
additional prognostic information incremental to clinical data in patients
with diabetes who are unable to undergo exercise stress testing
