Background: The coronary reperfusion in patients with ST-elevated myocardial infarction (STEMI) is often complicated by reperfusion-ischemic myocardial injury: microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH). Contrast-enhanced cardiac magnetic resonance imaging (MRI) is the best diagnostic method, which allows to assess these phenomena. It is known that in patients with STEMI and primary percutaneous coronary intervention (PCI), the prevalence rates of MVO and IMH are 50–60% and 40–50%, respectively. There is not enough knowledge about the prevalence of these phenomena in patients with pharmaco-invasive strategy.
Purpose: The aim of the study was to evaluate the prevalence of MVO and IMH in patients with primary STEMI and different reperfusion strategies.
Materials and methods: This observational cohort study included 47 patients with primary STEMI within the first 12 hours after the onset of disease. Exclusion criteria: pulmonary edema, cardiogenic shock, creatinine clearance <30 mL/min or dialysis, severe comorbidity, acute psychotic disorders, and inability to undergo or contra-indications for MRI. These patients were divided into 2 groups. Patients of group 1 (n=30) were treated with a pharmaco-invasive strategy. Fibrinolysis was performed in all patients in the pre-hospital setting. Patients of group 2 (n=17) were treated by primary PCI. MRI was performed at day 2 post-STEMI in all patients. Late gadolinium enhancement and T2-weighted IMH imaging for microvascular obstruction and IMH were used.
Results: Patients with primary PCI more often had MVO: 70.5% (n=12) vs. 40% (n=12) in the pharmaco-invasive group (p=0.05). The occurrence of IMH between the groups did not significantly differ: 40% (n=12) in group 1 vs. 64.7% (n=11) in group 2, respectively. The presence of combination of MVO with IMH was observed significantly more often in group of primary PCI: 47% (n=8) vs. 20% (n=6) (p=0.03). The left ventricular ejection fraction was significantly lower in patients with combination of IMH and MVO compared to those without it: 55% (34–66) vs. 62.5% (53–72) (p=0.01).
Conclusion: MVO and IMH were common findings in patients with primary STEMI and different reperfusion strategies and were present in 40% to 70% of patients. The MVO and combination of MVO with IMH occurred significantly more often in the group of primary PCI. The prevalence rates of IMH in patients with different reperfusion strategies did not significantly differ.
ClinicalTrials.gov, identification number is NCT03677466.