Prognostic value at 5 years of microvascular obstruction after acute myocardial infarction assessed by cardiovascular magnetic resonance

Abstract

BackgroundEarly and late microvascular obstruction (MVO) assessed by cardiovascular magnetic resonance (CMR) are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI). However, there is a lack of studies with long-term follow-up periods (>24 months).MethodsSTEMI patients reperfused by primary angioplasty (n = 129) underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %), left ventricular myocardial mass (LVMM) and total infarct size (% of LVMM) were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization.ResultsFollow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002) and a lower EF (mean: 39% vs. 46%, p = 0.006). The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p < 0.05). The presence of early MVO was associated with a reduced event-free survival (log-rank p < 0.05). Early MVO was identified as the strongest independent predictor for the occurrence of the primary endpoint in the multivariable Cox regression analysis adjusting for age, ejection fraction and infarct size (hazard ratio: 2.79, 95%-CI 1.25-6.25, p = 0.012).ConclusionEarly MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI.

The role of circulating microRNAs in acute coronary syndromes: ready for prime time?

“…In this study miR-133a levels were associated with decreased myocardial salvage, larger infarct size and microvascular obstruction (19) as determined by cardiac magnetic resonance in a clearly defined study population of n=216 consecutive STEMI patients. Although miR133a was a univariate predictor of mortality and MACE (HR: 1.28) the use of cardiac magnetic resonance for infarct characterisation (20) allowed the authors to demonstrate, that this association is not independent of infarct characteristics (18).…”

Protective Effect of Pre-Infarction Angina on Microvascular Obstruction After Primary Percutaneous Coronary Intervention Is Blunted in Humans by Cardiovascular Risk Factors

“…62, 63 Therefore, in order to fully exploit the favorable effect of PIA on MVO, careful treatment of CRFs is strongly recommended.…”

Novel MRI and CT Approaches for the Characterization of Myocardial Infarct

“…They concluded that not all infarcts with[50 % transmurality were nonviable, and MO detected with first pass assessment could help to stratify these cases better. Early MO, assessed by first-pass cardiac MR, has also been found to be an independent long-term prognostic indicator after acute MI [34].…”