Post-PCI corrected TIMI Frame Count predicts left ventricular global longitudinal strain at 90 days post-STEMI in thrombolysis-treated patients: A pre-specified analysis of the MIRTOS study.

Introduction: Ticagrelor has been established as the P2Y-inhibitor of choice in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI); however, its use has not been adequately studied in the context of thrombolysis. In the present study, we sought to investigate whether the administration of ticagrelor together with thrombolysis could result in a greater degree of left ventricular systolic function recovery compared to clopidogrel, at 90 days post-STEMI, as well as to evaluate post-PCI corrected TIMI Frame Count (CTFC) as a predictive marker of myocardial recovery in thrombolysis-treated patients.

Material And Methods: In this pre-specified analysis of the MIRTOS trial, the degree of change in left ventricular ejection fraction (ΔLVEF) and left ventricular longitudinal strain (ΔLV-GLS) from baseline to 90 days post-randomization in all patients who underwent conventional and speckle-tracking echocardiography at both timepoints was compared between the ticagrelor and clopidogrel groups. In addition, speckle-tracking echocardiographic measurements were evaluated for any correlations to post-PCI CTFC.

Results: No statistically significant differences were detected between the ticagrelor and clopidogrel groups for ΔLVEF (+3.61 ± 5.08 % versus +2.21 ± 4.78 %; P = 0.18) and ΔLV-GLS (-1.53 ± 2.7 % versus -1.21 ± 3.05 %; P = 0.73). A strong negative correlation was found between post-PCI CTFC and the absolute value of LV-GLS at 90 days post-randomization (r = -0.33, P = 0.014).

Conclusions: Our work suggests that both P2Y12-inhibitors are accompanied with a similar degree of myocardial recovery in the context of lytic therapy. Importantly, post-PCI microvascular integrity is a predictor of 3-month left ventricular systolic function in STEMI patients initially treated with thrombolysis.