Assessment of myocardial salvage in patients with STEMI undergoing thrombolysis: ticagrelor versus clopidogrel

Background In the setting of ST-segment elevation myocardial infarction (STEMI), the faster and stronger antiplatelet action of ticagrelor compared to clopidogrel, as well as its pleiotropic effects, could result in a greater degree of cardioprotection and final infarct size (FIS) limitation. The aim of our study was to comparatively evaluate the effect of ticagrelor and clopidogrel on myocardial salvage index (MSI) in STEMI patients undergoing thrombolysis. Methods Forty-two STEMI patients treated with thrombolysis were randomized to receive clopidogrel (n = 21) or ticagrelor (n = 21), along with aspirin. Myocardial area at risk (AAR) was calculated according to the BARI and the APPROACH jeopardy scores. FIS was quantified by cardiac magnetic resonance imaging (CMR) performed 5-6 months post-randomization. MSI was calculated as (AAR-FIS)/AAR x 100%. Primary endpoint of our study was MSI. Secondary endpoints were FIS and CMR-derived left ventricular ejection fraction (LVEF) at 5 -6 months post-randomization. Results By using the BARI score for AAR calculation, mean MSI was 52.25 [+ or -] 30.5 for the clopidogrel group and 54.29 [+ or -] 31.08 for the ticagrelor group (p = 0.83), while mean MSI using the APPROACH score was calculated at 51.94 [+ or -] 30 and 53.09 [+ or -] 32.39 (p = 0.9), respectively. Median CMR-derived FIS--as a percentage of LV--was 10.7% [+ or -] 8.25 in the clopidogrel group and 12.09% [+ or -] 8.72 in the ticagrelor group (p = 0.6). Mean LVEF at 5-6 months post-randomization did not differ significantly between randomization groups. Conclusions Our results suggest that the administration of ticagrelor in STEMI patients undergoing thrombolysis offer a similar degree of myocardial salvage, compared to clopidogrel. Keywords: STEMI, Thrombolysis, Clopidogrel, Ticagrelor, Myocardial salvage