Comparison of myocardial perfusion study and invasive hemodynamic measurement of the significance of non-infarct-related residual stenoses in ST elevation myocardial infarction patients.

BACKGROUND: Nearly 50% of ST elevation myocardial infarction (STEMI) patients have multivessel coronary artery disease. The optimal selection of non-culprit lesions for complete revascularization is a matter of current debate. Little is known about the predictive value of myocardial perfusion study (MPS) in this scenario. METHODS: We enrolled 49 STEMI patients (61.5 ± 10.3 years) with at least one major non-culprit lesion (50-90%) other than left main coronary artery lesions. Overall 63 non-infarct- related artery (IRA) stenoses (65.2 ± 11.9%) were recommended for further evaluation using Fractional Flow Reserve (FFR) measurement as is standard in our institution. Prior to FFR, all patients were scheduled for non-invasive MPS using single-photon emission computed tomography (SPECT). Both FFR and MPS were performed 4-8 weeks after STEMI with MPS preceding FFR within no more than 48 hours. An FFR value of ≤0.80 was considered significant and guided the final revascularization strategy. The results of MPS were correlated to FFR as well as to the clinical and angiographic characteristics of both culprit and non-infarct-related lesions. RESULTS: Based on FFR, 30 out of 63 stenoses (47.6%) in 27 patients were considered hemodynamically significant (FFR 0.69 ± 0.08, range 0.51-0.79) compared to residual 33 stenoses considered negative (FFR 0.87 ± 0.04, range 0.81-0.96). The MPS revealed abnormal myocardium (23.6% average, range 5-56%) in 21 patients (42.8%). Among those patients, only 9 showed the evidence of ischemic myocardium (average 10.8%, range 4-18%) with low sensitivity of MPS in predicting positive FFR. Besides that, higher proportion of patients (71.4% vs. 42.9%, P=0.047) with overall lower FFR values (0.73 vs. 0.80, P=0.014, resp.) in non-IRAs as well as higher proportion of patients with more severely compromised flow in IRAs (P=0.048) during STEMI had MPS-detected abnormal myocardium. CONCLUSION: In STEMI patients with multivessel coronary artery disease, we observed rather weak correlation between MPS using SPECT and invasive hemodynamic measurement using FFR in ischemia detection.

Complete revascularization of multivessel coronary artery disease in patients with ST elevation acute coronary syndrome - for whom and when? A comprehensive review.

Atherosclerosis is the most common cause of coronary steno-occlusive disease and acute myocardial infarction is the leading cause of death in industrialized countries. In patients with acute ST elevation myocardial infarction (STEMI), there is unquestionable evidence that primary percutaneous coronary intervention providing recanalization of the infarct related artery (IRA) is the preferred reperfusion strategy. Nevertheless, up to 50% of patients with STEMI have multivessel coronary artery disease defined as at least 50% stenosis exclusive of IRA. There is conflicting data regarding the optimal treatment strategy and timing in such patients. Currently, it is assumed that stable patients might benefit from complete revascularization particularly in reducing the need for future unplanned procedures but only culprit lesion should be treated during index procedure in unstable patients. In this article, we provide a comprehensive overview of this important and currently highly debated topic.

Comparison of angiographic estimation and invasive hemodynamic measurement of the significance of non-infarct-related residual stenoses in ST-elevation myocardial infarction patients.

Introduction: Up to 50% of patients with ST elevation myocardial infarction (STEMI) have ≥ 50% stenosis in a major non-infarct-related artery. Several studies have evaluated the prognostic value of the completion of revascularization with overall inconclusive results. Selection of the stenoses was based on the angiographic evaluation, invasive hemodynamic measurement or the combined approach. It is unknown whether such a selection provides correlation of comparable patient groups. Material and methods: We enrolled 51 patients (62.7 ±10.2 years) with acute STEMI and at least one residual (50-90%) stenosis in a non-infarct-related major coronary artery (excluding left main coronary artery). Overall 65 stenoses (67.9 ±10.7%) were evaluated angiographically following primary percutaneous coronary intervention and the hemodynamic significance was estimated with respect to the stenosis severity, caliber of the arterial segment, localization of the stenosis (proximity) as well as the estimated size of the supplied vascular territory. During subsequent hospitalization, invasive measurement of the hemodynamic significance using fractional flow reserve (FFR) was performed to guide the final revascularization strategy (FFR value of ≤ 0.80 considered significant). Results: Based on angiographic evaluation, a total of 44 stenoses would be recommended for treatment, whereas only 31 stenoses were revascularized based on FFR measurement. Moreover, visual evaluation and hemodynamic measurement were discrepant in 27 of 65 (41.5%) stenoses. Conclusions: We observed a weak correlation between visual angiographic evaluation and invasive hemodynamic measurement. More stents would be implanted based on angiographic evaluation compared to FFR measurement.