Evolution of myocardial perfusion during primary angioplasty in spontaneously reperfused infarct-related artery: impact on long-term clinical outcomes and left ventricular function recovery

Abstract

Background: TIMI myocardial perfusion grade (TMPG) reflects the integrity of microvasculature in ST-elevation myocardial infarction (STEMI). We sought to investigate whether TMPG evolution during primary angioplasty (pPCI) in spontaneously reperfused STEMI patients might predict long-term outcomes.

Methods: 392 patients with TIMI-3 flow before pPCI were analyzed. According to pre- and post-pPCI TMPG four reperfusion patterns were created: A. TMPG deterioration from grade 2/3 to 0/1 after pPCI (n = 55, 14.0%), B. TMPG-0/1 before and after pPCI (n = 111, 28.3%), C. TMPG improvement from grade 0/1 to 2/3 (n = 52, 13.3%), D. TMPG-2/3 before and after pPCI (n = 174, 44.4%). 30-day and 1-year mortality and heart failure requiring hospitalization (HF-hosp) were recorded. Left ventricular ejection fraction (LVEF) was measured at first day (1D) and after 6 months (6M).

Results: 1D-LVEF was similar in A-D groups. After 6M, LVEF improved in pattern D (7.5 ± 5.4%, p<0.01) and C (3.7 ± 3.4%, p < 0.05), deteriorated in pattern A (5.2 ± 3.9%, p<0.01) and did not change in pattern B. 6M-LVEF increased (p < 0.001) and frequency of 1-year HF-hosp decreased (p < 0.001) in stepwise fashion among A-D patterns. A 30-day mortality rate for A-D patterns was 9.1%, 2.7%, 1.9% and 0%, respectively (p < 0.001). 1-year mortality was 16.3%, 7.2%, 5.8% and 0.6%, respectively (p < 0.001). By multivariate analysis (c-index = 0.79), TMPG evolution was independent predictor of 1-year mortality (HR = 2.5, 95%CI 1.3-4.0, p = 0.006).

Conclusions: Maintaining TMPG-2/3 or improving TMPG-0/1 through pPCI in STEMI implies LV function recovery and good long-term survival. In contrast, substantial deterioration of TMPG is associated with lack of LV function recovery, and the highest mortality rate.