Detection of target lesion related ischemia in patients suffering from multivessel disease using Tc-99m sestamibi single photon emission computer tomography: A comparison with fractional flow reserve

Abstract

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Objectives: In patients with multivessel disease both the detection of the culprit lesion and the exact allocation are important preconditions for sufficient treatment and improved outcome. In a vessel based approach the combination of quantitative coronary angiography (QCA) and fractional flow reserve (FFR) measured by a pressure wire should be advantageous compared to myocardial SPECT (MS), as morphological and functional information is delivered simultaneously. Therefore our aim was to evaluate MS in the detection and allocation of hemodynamically significant stenoses obtained by the combined gold standard QCA plus FFR in patients with multivessel disease. Methods: FFR and QCA of 95 vessels in 80 patients (26 f, 54 m) have been evaluated. Hemodynamically significant target lesions were defined as intermediate stenoses between 50 and 75% with an FFR<0.75. Ergometry or pharmacological stress was performed when appropriate. MS data was acquired according to a single-day stress/rest protocol by use of Tc- 99m sestamibi. Detection of perfusion defects has been performed by semiquantitative analysis, calculating regional summed stress (SSSr) and summed difference scores (SDSr). Allocation of perfusion defects to specific vessels has been performed according to standard criteria. Results: In patients without (n=37) and with prior MI (n=43) sensitivity, specificity, negative and positive predictive value of MS in the detection of significant stenoses were 77%, 80%, 59%, 90% and 79% and 60%, 85%, 75%, 74% and 74%, respectively. In patients with prior MI 8/12 and in patients without prior MI 4/10 perfusion defects were allocated wrongly, compared to the defined gold standard (QCA plus FFR). Conclusions: MS of multivessel disease patients without prior MI showed a good correlation with QCA and FFR in the detection of hemodynamically significant coronary artery stenoses. However in patients with prior MI, sensitivity in the detection of residual ischemia was weak and allocation of perfusion defects was complicated.