Patency and Reinfarction in Late-Entry Myocardial Infarct Patients Treated with Reperfusion Therapy

Abstract

Patency of the infarct-related vessel is associated with a more favorable long-term prognosis after acute myocardial infarction (AMI). High infarct vessel patency is reported for early reperfusion therapy, but data on patency and its possible effect on clinical outcome are less abundant for patients presenting late after the acute event. The aim of this study was to investigate whether time to reperfusion is related to infarct-vessel patency and clinical outcome. This study compares 268 patients who presented with symptoms of AMI within six hours after the onset of symptoms (Early) with 33 patients who had reperfusion therapy for signs of ongoing ischemia more than six hours after the start of chest pain (Late). At follow-up coronary angiography, flow through the infarct-related vessel was assessed according to the thrombolysis in myocardial infarction (TIMI) classification. Vessels were considered occluded if TIMI flow grade 0 or 1 was present. Follow-up angiography was performed in 95% of patients after a mean of forty-eight days. The infarct-related vessel was occluded in 41% of the late-entry patients (13 of 32), and in 17% of those presenting early (44 of 252), (P = 0.01; relative risk [RR]: 2.50; 95% confidence interval [CI]: 1.26 to 6.83). This was associated with a higher rate of recurrent myocardial infarction in late-entry patients: 27% (9 of 33), compared with 9% (25 of 268) in the early group (P = 0.005; RR: 2.94; 95% CI: 1.50 to 5.81). Thus, in the present study, late reperfusion therapy (after six hours) was associated with a higher recurrent myocardial infarction rate and a lower infarct vessel patency rate, compared with early treatment of patients.

Aspiration Thrombectomy for Treatment of ST-segment Elevation Myocardial Infarction: a Meta-analysis of 26 Randomized Trials in 11 943 Patients

“…Procedural outcomes extracted included a surrogate marker of epicardial reperfusion, namely failure to reach TIMI flow grade 3 18 ; 2 surrogate markers of myocardial reperfusion, namely failure to reach MBG grade 3, 19 and incomplete ST-segment elevation resolution (iSTR, resolution of < 70% of the sum of the initial ST-segment elevation) 20 ; as well as absence of direct stenting, 21 and evidence of distal embolization. 7 Prespecified clinical endpoints included all-cause death, reinfarction, target vessel revascularization, definite stent thrombosis, and stroke.…”

Impact of Community Intervention to Reduce Patient Delay Time on Use of Reperfusion Therapy for Acute Myocardial Infarction Rapid Early Action for Coronary Treatment (REACT) Trial

“…Early coronary reperfusion therapy has been associated with better coronary patency rates, lower mortality, 1,2 and lower recurrent AMI rates. 11 We found no significant trend in reperfusion therapy outcomes when analyzed over the entire intervention. However, our secondary analyses (Figs.…”

Assessment of Coronary Artery Flow Velocity Pattern as a Long-Term Predictor of Left Ventricular Function and Cardiac Events after Percutaneous Coronary Intervention in Anterior Acute Myocardial Infarction

“…The success of PCI was defined as a residual stenosis of less than 30% with TIMI flow of grade 2 or 3 assessed as previously described (7). Myocardial blush grade (MBG) was assessed on the final angiogram during angioplasty and was confirmed independently and blindly on the same view of the follow-up angiogram by another experienced investigator, based on the visual assessment of contrast opacification of myocardial territory subtended by the infarct vessel as previously described (8). The criteria of MBG were as follows: 0=no myocardial blush or contrast density; 1=minimal myocardial blush or contrast density; 2= moderate myocardial blush or contrast density but less than that obtained during angiography of a contralateral or ipsilateral non-infarct-related coronary artery; and 3=normal myocardial blush or contrast density compared with that obtained during angiography of a contralateral or ipsilateral non-infarct-related coronary artery.…”