Impact of reperfusion timing and methods on myocardial structure and function in ST-segment elevation myocardial infarction

Aim. To compare the effectiveness of primary percutaneous coronary intervention (PPCI) and a pharmacoinvasive strategy (PIs) for revascularization, and to study the impact of their timing on the morphofunctional and electrophysiological myocardial characteristics in patients with ST-segment elevation myocardial infarction. Material and methods. A total of 185 patients aged 53±9 years were included. On days 7-10, patients underwent cardiac magnetic resonance imaging (MRI), speckletracking echocardiography, and Holter monitoring. Results. Subjects were divided into following groups: the early reperfusion (ER) group included 97 patients with an onset-to-revascularization time ≲180 minutes; and the delayed reperfusion (DR) group included 88 patients with an onset-to-revascularization time >180 minutes. According to MRI, scar tissue mass in the DR group was 24,7 (13,6; 42,9) g versus 15,9 (5,9; 30,7) g in the ER group (p=0,003). In the ER group, a more pronounced proportion of the heterogeneous area relative to the scar was observed compared to the DR group (p=0,018). The global contrast index in the ER group was 17,7 (10,3; 33,1)%, and in the DR group — 25 (16,2; 38,2)% (p=0,014). According to the echocardiography, lower values of global work efficiency with a simultaneous increase in global wasted work were revealed in the DR group (p<0,05). According to Holter monitoring data, the incidence of high-grade premature ventricular contractions in the ER group was 1% vs 9% in the DR group (p=0,011). At the next stage, 97 patients with a reperfusion time ≲180 min were divided into following groups: group 1-54 patients in whom PIs was used; group 2-43 patients with PPCI. No differences were found between the groups according to cardiac MRI, speckle-tracking echocardiography, and Holter monitoring. Conclusion. A reperfusion delay of >180 min is associated with the most unfavorable characteristics of ischemic injury according to MRI, myocardial work according to speckle-tracking echocardiography, and Holter monitoring data. A comparative analysis of patients with PPCI and PIs performed in the first 180 minutes did not demonstrate differences in morphofunctional and electrophysiological myocardial characteristics.