Acute Heart Failure and Coronary Blood Flow in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: An Observational Cohort Study

Background and objective The Global Registry of Acute Coronary Events (GRACE) study showed poor outcomes in ST-elevation myocardial infarction (STEMI) patients with acute heart failure (AHF) at hospital admission in terms of increased in-hospital and six-month mortality and readmission rates. In this study, we aimed to examine the effects of AHF at the time of admission on the coronary thrombus burden and post-primary percutaneous coronary intervention (PPCI) coronary flow among STEMI patients. Methods We conducted a cohort study involving 210 consecutive STEMI patients who presented to a single PPCI centre between June 2016 and January 2017. We classified them into two groups based on their Killip class at the time of presentation to the emergency department: no heart failure (NHF) and AHF groups. The primary outcome was the incidence of Thrombolysis In Myocardial Infarction (TIMI) flow grade of less than 3 in the stented coronary artery in the absence of mechanical obstruction or dissection (also known as no-reflow). The secondary outcome was the presence of a heavy thrombus burden (TIMI grade 4 or 5) at the time of angiography. Results The AHF group had a significantly higher incidence of no-reflow than the NHF group (25% vs. 8.4%, p=0.019). However, the prevalence of heavy thrombus burden did not differ significantly between the two groups (50% in the AHF group vs. 43.16% in the NHF group, p=0.557). The multivariable logistic regression analysis showed that AHF was an independent predictor of no-reflow in STEMI patients post-PPCI Odds ratio (OR): 3.59, 95% confidence interval (CI): 1.09-11.83, p=0.035. Conclusion Based on our findings, AHF is associated with an increased risk of no-reflow in STEMI patients post-PPCI, irrespective of the coronary thrombus load.