Purpose: To compare the long-term prognostic value of dobutamine stress echocardiography and dobutamine stress single photon emission computed tomography (SPECT) in patients unable to perform an exercise test.
Methods: We assessed the prognostic value of dobutamine stress technetium 99m ((99m)Tc)-sestamibi SPECT and dobutamine stress echocardiography in 301 patients who were unable to perform exercise tests. Outcomes during a mean (+/- SD) follow-up of 7.3 +/- 2.8 years were overall death, cardiac death, nonfatal myocardial infarction, and late (>60 days) coronary revascularization.
Results: Abnormal myocardial perfusion was detected in 66% of patients (n = 198), while 60% (n = 182) had an abnormal stress echocardiogram; agreement was 82% (kappa = 0.62). During the follow-up period, 100 deaths (33%) occurred, of which 43% were due to cardiac causes. Nonfatal myocardial infarction occurred in 23 patients (8%), and 29 (10%) underwent late revascularization. With stress SPECT, annual event rates were 0.7% for cardiac death and 3.6% for all cardiac events after a normal scan, and 2.6% for cardiac death and 6.5% for all cardiac events after an abnormal scan (P <0.0001). For stress echocardiography, annual event rates were 0.6% for cardiac death and 3.3% for all cardiac events after a normal test, and 2.8% for cardiac death and 6.9% for all cardiac events after an abnormal test (P <0.0001).
Conclusion: Dobutamine stress (99m)Tc-sestamibi SPECT and dobutamine stress echocardiography provide comparable long-term prognostic information in addition to that afforded by clinical data.