Role of biomarkers of myocardial injury and inflammation in predicting ischemia-reperfusion injury in patients with ST-segment elevation acute coronary syndrome undergoing endovascular revascularization

Aim. To evaluate the informative value of biomarkers (cardiac troponin l (cTnl), high-sensitivity C-reactive protein (hsCRP), N-terminal pro-brain natriuretic peptide (NTproBNP), stimulating growth factor (ST2)) as laboratory markers of myocardial ischemia-reperfusion injury in patients with ST-segment elevation acute coronary syndrome (STEACS) undergoing endovascular revascularization.Material and methods. The study included 115 patients with STEACS who underwent endovascular myocardial revascularization. To identify the informative value of biomarkers, the levels of cTnl, NTproBNP, hsCRP, sST2 were analyzed at baseline, as well as after reperfusion therapy on the 2nd (cTnl) and 5th (sST2, hsCRP, NTproBNP) days. Contrast-enhanced cardiac magnetic resonance imaging was performed 5 days after endovascular intervention.Results. Microvascular obstruction was detected in 54 patients (47%), of which 24 (44%) patients had a combination of microvascular obstruction and myocardial hemorrhage. ln 61 cases (53%), no microvascular damage was registered. lt was found that with an increase in the threshold initial NTproBNP levels >590 pg/ml, the odds ratio (OR) of myocardial reperfusion injury was 12,2 (95% confidence interval (CI), 4,81-30,92, p<0,001). In addition, we analyzed biomarker levels in the early period after myocardial infarction, at which threshold values of reperfusion injury parameters were established as follows: for cTnI >8,1 ng/ml, OR=7,17 (95% CI, 3,11-16,53, p=0,001); for hsCRP >14 mg/L, OR=12,71 (95% CI, 5,03-32,08, p=0,001); for NTproBNP >334 pg/ml, OR=11,8 (95% CI, 4,88-28,59, p=0,001); for sST2 >41 ng/ml, OR=7,17 (95% CI, 3,11-16,53, p=0,001). According to multivariate analysis, predictors of microvascular injury were the initial NTproBNP values, as well as the cTnI, hsCRP, and sST2 values in the early postinfarction period (sensitivity — 89,5%, specificity — 83,3%).Conclusion. Thus, the initial NTproBNP, as well as cTnI, hsCRP, sST2 values after percutaneous coronary intervention are more informative for assessing the risk of microvascular damage.

Effect of remote ischaemic conditioning on infarct size and remodelling in ST-segment elevation myocardial infarction patients: the CONDI-2/ERIC-PPCI CMR substudy

The effect of limb remote ischaemic conditioning (RIC) on myocardial infarct (MI) size and left ventricular ejection fraction (LVEF) was investigated in a pre-planned cardiovascular magnetic resonance (CMR) substudy of the CONDI-2/ERIC-PPCI trial. This single-blind multi-centre trial (7 sites in UK and Denmark) included 169 ST-segment elevation myocardial infarction (STEMI) patients who were already randomised to either control (n = 89) or limb RIC (n = 80) (4 × 5 min cycles of arm cuff inflations/deflations) prior to primary percutaneous coronary intervention. CMR was performed acutely and at 6 months. The primary endpoint was MI size on the 6 month CMR scan, expressed as median and interquartile range. In 110 patients with 6-month CMR data, limb RIC did not reduce MI size [RIC: 13.0 (5.1–17.1)% of LV mass; control: 11.1 (7.0–17.8)% of LV mass, P = 0.39], or LVEF, when compared to control. In 162 patients with acute CMR data, limb RIC had no effect on acute MI size, microvascular obstruction and LVEF when compared to control. In a subgroup of anterior STEMI patients, RIC was associated with lower incidence of microvascular obstruction and higher LVEF on the acute scan when compared with control, but this was not associated with an improvement in LVEF at 6 months. In summary, in this pre-planned CMR substudy of the CONDI-2/ERIC-PPCI trial, there was no evidence that limb RIC reduced MI size or improved LVEF at 6 months by CMR, findings which are consistent with the neutral effects of limb RIC on clinical outcomes reported in the main CONDI-2/ERIC-PPCI trial.

Combined protocol for remote ischemic conditioning as the method of cardioprotection in patients with acute ST-segment elevation myocardial infarction

Background. There is currently no commonly accepted strategy for limiting the reperfusion injury that occurs after revascularization in patients with myocardial infarction. This study aimed to investigate the efficacy of a promising cardioprotective method.Material and Methods. Patients with acute anterior ST-segment elevation myocardial infarction (STEMI) (n = 87) were included in an open-label prospective randomized controlled trial. Control group comprised patients with STEMI who underwent only primary percutaneous coronary intervention (PPCI) (n = 44). Patients of intervention group (n = 43) underwent PPCI and remote ischemic perconditioning combined with postconditioning (RIC). The efficacy of RIC was assessed based on cardiac magnetic resonance (CMR) imaging data.Results. The medians of left ventricular (LV) infarct size were significantly higher in patients of control group: 44.8 (33.6; 55.5) versus 52.7 (35.5; 73.9) mL (p = 0.039) at day 10 after STEMI and 34.0 (25.8; 39.8) mL versus 46.0 (32.8; 55.0) mL six months after STEMI in control and intervention groups, respectively (p = 0.004). The groups of patients did not differ in the sizes of area at risk relative to the total LV myocardial volume: 40 (35; 45) and 43 (34; 49)% in control and intervention groups, respectively (р = 0.232). The groups significantly differed in the ratios of infarct size to area at risk: 70.3 (65.1; 86.6)% in control group versus 63.5 (52.7; 72.0)% in intervention group (р = 0.014) as well as in the myocardial salvage indexes: 29.7 (13.5; 34.9)% in control group versus 36.5 (28.0; 47.3)% in intervention group (р = 0.014). The study showed the tendency to greater LV myocardial salvage in intervention group versus control group at six-months follow-up (р = 0.073). The groups significantly differed in the medians of microvascular obstruction volume: 1.9 (1.4; 2.9) mL in intervention group versus 2.5 (1.8; 8.1) mL in control group (p = 0.049) as well as in the proportions of microvascular obstruction in the LV myocardium: 0.94 (0.79; 1.37)% in intervention group versus 1.50 (0.89; 3.66)% in control group (р = 0.046).Conclusion. The RIC method combined with PPCI contributed to the limitation of infarct and microvascular obstruction sizes and was associated with an increase in the myocardial salvage index in STEMI patients.