Comprehensive assessment of microcirculation after primary percutaneous intervention in ST-segment elevation myocardial infarction

Abstract

ObjectivesA pathophysiological mechanism of microvascular dysfunction in ST-segment elevation myocardial infarction (STEMI) is multifactorial; thus, multiple modalities were needed to precisely evaluate a microcirculation.MethodsWe complementarily assessed microcirculation in STEMI by the index of microcirculatory resistance (IMR) and coronary flow reserve (CFR) immediately after a primary percutaneous intervention in 89 STEMI patients. Cardiovascular and cerebrovascular events (MACCE) including cardiovascular death, target vessel failure, heart failure, and stroke were assessed during a mean follow-up period of 3.0 years.ResultsThe microcirculation of enrolled patients was classified into four groups using cutoff CFR and IMR values (CFR>2 and mean IMR): group-1 (n=23, CFR>2 and IMR≤27); group-2 (n=31, CFR≤2 and IMR≤27); group-3 (n=9, CFR>2 and IMR>27); and group-4 (n=26, CFR<2 and IMR>27). On echocardiography 3 months later, improvement in the wall motion score index was shown in group-1 (P<0.01), group-2 (P<0.01), and group-3 (P=0.04), whereas group-4 did not show improvement in wall motion score index (P=0.06). During clinical follow-up, there were no MACCE in group-1 and the patients in group-2 and group-3 showed significantly lower MACCE compared with group-4 (group-1=0%, group-2, and group-3=10%, group-4=23.1%, P=0.04).ConclusionComplimentary assessment of microcirculation by the IMR and CFR may be useful to evaluate myocardial viability and the long-term prognosis of STEMI patients.

Comparative Prognostic Utility of Indexes of Microvascular Function Alone or in Combination in Patients With an Acute ST-Segment–Elevation Myocardial Infarction

“…13 The combination of an increased IMR and reduced CFR has been associated with enhanced detection of microvascular obstruction 18 and viability and prognosis. 16 However, in that study, only 10 major adverse cardiac and cerebrovascular events occurred, of which 5 were revascularizations. Changes in IMR and CFR within 24 hours after reperfusion have been associated with LV ejection fraction (LVEF).…”

“…14 CFR is associated with composite cardiovascular outcomes, including revascularization, in patients with stable coronary disease 15 and after acute STEMI. 16 We have recently shown that IMR is more closely associated with severe microvascular pathology, LV remodeling, and health outcome than either the angiogram or CFR, 17 but whether the combination of IMR and CFR adds prognostic value is uncertain.…”

“…Changes in IMR and CFR within 24 hours after reperfusion have been associated with LV ejection fraction (LVEF). 19,20 However, prior studies are limited by sample size (n=27–45 subjects), 10,20–22 short follow-up (3–6 months), 10,18,20–22 lack of association with spontaneous hard outcomes, 16 and differences in cutoffs, 12,23 supporting the case for definitive research.…”

Physiological Lesion Assessment in STEMI and Other Acute Coronary Syndromes

“…In a meta-analysis of six studies, a median IMR > 40 was an independent predictor of death [20]. In some studies, the combination of a high IMR and reduced CFR enhances the detection of microvascular obstruction, but in other studies, the combination did not have any prognostic value [21,22].…”

Physiologic Evaluation of Microvascular Damage in Culprit Vessel After Successful Primary Percutaneous Coronary Intervention for ST-elevation Myocardial Infarction Patients

“…5,6 In this case report, we presented the results from the comprehensive physiologic assessment in culprit vessel after primary PCI in STEMI patients and validated the results using cardiac MR findings. There is acute and overt inflammatory change in myocardial cell and vasculature, especially in acute phase of myocardial infarction.…”