Abstract
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Objectives: Myocardial SPECT (MS) has shown a high sensitivity of up to 90% in the detection of multivessel coronary artery disease. However, the detection of residual ischemia after MI, which is an important finding for risk stratification, as well as the allocation of ischemia related perfusion defects to target vessels, is complicated in these patients. Our aim was to evaluate MS in the detection of target vessel related ischemia in patients with multivessel disease with/without prior MI in comparison to FFR measurements, assumed as the reference method
Methods: 75 patients (25 women; mean age 67 ± 10 yrs) with multivessel disease were prospectively investigated. Ergometry or pharmacological stress (dipyridamole and dobutamine) was performed as appropriate, MS data was acquired as a single-day stress/rest protocol by use of Tc- 99m sestamibi. For image interpretation semiquantitative analysis was conducted by calculating regional summed stress (SSSr) and summed difference scores (SDSr) as described elsewhere [1]. Within 13 (± 43) days, coronary angiography was performed and FFR of 89 vessels was calculated by use of a pressure wire (normal FFR ≥0.75). For statistical analysis patients were divided into three groups: patients without prior MI (group 1, 44 measured vessels), patients with prior MI in the target vessel territory (group 2, 14 measured vessels) and patients with prior MI outside the target vessel territory (group 3, 31 measured vessels)
Results: A pathological FFR was measured in 29 vessels (13 with FFR values between 0.72 and 0.78), while 27 vessels have been considered causing ischemia in the MS (SDSr ≥1). Sensitivity, specificity, negative and positive predictive value of SDSr for the detection of pathological FFR values in the target region were 83%, 81%, 63%, and 93%, respectively, in group 1, 50%, 100%, 100%, and 73%, respectively, in group 2 and 64%, 95%, 88%, and 83%, respectively, in group 3
Conclusions: Good correlation was found between MS and FFR measurements for the detection of myocardial ischemia in patients with multivessel disease without prior myocardial infarction. However, sensitivity was weak in the detection of residual ischemia after prior myocardial infarction
- Society of Nuclear Medicine, Inc.