Prognostic value of myocardial perfusion SPECT versus exercise electrocardiography in patients with ST-segment depression on resting electrocardiography
✍ Scribed by Andrea De Lorenzo; Rory Hachamovitch; Xingping Kang; Heidi Gransar; Maria G. Sciammarella; Sean W. Hayes; John D. Friedman; Ishac Cohen; Guido Germano; Daniel S. Berman
- Publisher
- Springer
- Year
- 2005
- Tongue
- English
- Weight
- 137 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1071-3581
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✦ Synopsis
Background:
The value of exercise-induced st-segment depression for the prognostic evaluation of patients with 1 mm of st depression or greater on the resting electrocardiogram is controversial.
Methods and results:
Patients who underwent exercise myocardial perfusion single photon emission computed tomography (mps) and had resting st depression of 1 mm or greater with a nondiagnostic exercise electrocardiographic response (n = 1122) were followed up for 3.4 +/- 2.3 years. those with paced rhythm, pre-excitation, left bundle branch block, or myocardial revascularization within the first 60 days after mps were excluded. additional exercise-induced st-segment depression was considered significant if > or = 2 mm mps was scored semiquantitatively by use of a 20-segment model of the left ventricle; the percentage of myocardium involved with stress defects (% myo) was derived by normalizing to the maximal possible score of 80. hard events were defined as nonfatal myocardial infarction or cardiac death. a cox analysis was used to determine independent predictors of hard events among clinical, exercise, and nuclear variables. hard event rates increased as a function of % myo for either patients with exercise-induced st depression (1.4%/y for normal mps vs 4.1%/y for % myo >10%, p < .03) or those without it (0.7%/y for normal mps vs 3.0%/y for % myo >10%, p = .0001). age, diabetes mellitus, shortness of breath as the presenting symptom, and % myo were independent predictors of hard events. exercise-induced st depression was predictive of hard events only when it was 3 mm or greater. the presence and extent of perfusion defects, reflected in the % myo, had incremental prognostic value over clinical variables and also over all degrees of exercise-induced st depression.
Conclusions:
Although mps effectively risk-stratifies patients with resting st depression of 1 mm or greater, the prognostic value of exercise-induced st depression is limited in these patients, with a small added risk when severe (> or = 3 mm).