Introduction:

Infarct healing and fibrotic turnover are characteristic sequelae after acute myocardial infarction impacting on structural changes and leading to the development of chronic heart failure (CHF). Cardiac Magnetic Resonance Imaging (cMRI) is the gold standard to assess cardiac volumes and function. Biomarkers are routinely assessed to describe the clinical severity of heart failure. However, it remains unclear which biomarker best mirrors CHF-related MR-morphologic changes after acute ST-Elevation Myocardial Infarction (STEMI).

Purpose:

To evaluate the correlation and prognostic value of circulating biomarkers at baseline with MR-morphologic changes at 12 months in patients after the first STEMI.

Methods:

Patients with a first STEMI recruited at a single center from the ETICS cohort with available serum samples for measurement of biomarkers at baseline (day 1-9), 6 months and 12 months and available cardiac MRI 3 Tesla scans performed at baseline (day 1-4), short-term (day 7-9) and long-term (12 months) follow-up were included in the current analysis. Biomarkers comprised hsTnT, NTproBNP, ST2 (soluble interleukin 1 receptor-like 1) and CCN1 (Cysteine-rich angiogenic inducer 61 (Cyr61)). Intergroup comparisons over time were performed for each biomarker for all three time-points using Kruskal-Wallis and Wilcoxon tests. Correlations between individual biomarkers and MR-morphologic parameters comprising left ventricular ejection fraction (LVEF), microvascular obstruction (MVO), left ventricular end-systolic volume (LVESV) and left ventricular mass (LVM) were analyzed using Spearman rank analysis. Multiple regression analysis was performed to evaluate associations of biomarkers with dichotomized MR-parameters based on the median. Adjustments were performed for age, renal function (eGFR MDRD formula) and biomarkers NTproBNP and hsTnT to delineate an odds ratio (OR) with confidence interval (CI) for a change in biomarker concentration in the magnitude of a standard deviation (SD) (z-score) to predict categorization above or below the median of MR-parameters.

Results:

Among 49 patients with STEMI (mean age 55.9 ± 11.4 years) with 1-2-3 vessel disease (27 (55.1%) – 16 (32.7%) - 6 (12.2%), respectively; n (%)), prevalent risk factors comprised hypertension (20; 40.8%), diabetes (8; 16.3%), hypercholesterolemia (9, 18.4%). PCI was successful in 48 patients (98.0%) with stent implantation in 46 patients (93.9%) at a pain-to-balloon time of 210 min (150-510) (median; IQR). Baseline levels of hsTnT, NTproBNP and ST2 were significantly higher at baseline compared to the values at 6 and 12 months, whereas CCN1 levels were increased at baseline compared to the values at 6 and 12 months (Figure 1). A consistent pattern of strong correlations (p<0.001) was found for baseline hsTnT with MR parameters at 12 months: LVEF (rho=-0.61), MVO (rho=0.54). LVESV (rho=0.51) and LVM (rho=0.54). Multivariable analysis identified baseline hsTnT as the only independent predictor of MR-parameters at 12 months (above or below the median) for LVEF: OR 0.18 (CI 0.06, 0.56) p=0.003; MVO: OR 2.65 (CI 1.1, 6.43) p=0.031; LVESV OR 3.59 (CI 1.39,  9.25) p=0.008; LVM OR 2.65 (CI 1.1, 6.43)  p=0.031.

Conclusions: 

After STEMI, baseline hsTnT is the only one of four analyzed biomarkers, which was strongly correlated with CHF-related structural left ventricular pathology at 12 months suggesting a simple biomarker-related strategy to inform treatment decisions.

Figure 1: