We sought to assess the impact of different oral P2Y12 receptor inhibitors on residual thrombus and reperfusion indexes in ST-segment elevation myocardial infarction patients enrolled in the COCTAIL II trial, which included 128 primary percutaneous coronary interventions randomized to intracoronary vs. intralesion abciximab bolus with or without thrombectomy.
Patients were divided into three groups: clopidogrel (n = 44), prasugrel (n = 45) and ticagrelor (n = 39). Residual intra-stent thrombus was quantified by optical coherence tomography using both the number of cross-sections with thrombus area more than 10% and thrombus volume. Reperfusion indexes included thrombolysis in myocardial infarction (TIMI) flow, corrected TIMI frame count, myocardial blush grade (MBG) and complete ST-segment resolution (≥70%).
In the prasugrel group, optical coherence tomography depicted a lower percentage of cross-sections with residual thrombus area more than 10% [4.0 (1.0–8.5)], as compared with clopidogrel [8.0 (1.0–15.0), P = 0.011] and ticagrelor [7.0 (3.0–13.5), P = 0.026].A higher thrombus volume was found in the clopidogrel group 4.0 mm3(2.7–6.2) as compared with the prasugrel group [2.8 mm3(1.8–4.4), P = 0.023], whereas the other between-group comparisons yield no significant differences. The frequency of MBG 3 was higher in the prasugrel group (73.3%) as compared with clopidogrel (45.5%) and ticagrelor [(56.4%), P = 0.027]. Final TIMI flow, TIMI frame count and ST resolution were not significantly different across the three groups (P = 0.423, 0.179 and 0.848, respectively). At multivariate analysis, pretreatment with prasugrel was independently associated with MBG 3 (odds ratio = 3.93; 95% confidence interval = 1.01–15.39).
Prasugrel loading dose was associated with a lower percentage of cross-sections with residual thrombus area more than 10% as compared with both clopidogrel and ticagrelor, although intrastent thrombus volume was not significantly different between prasugrel and ticagrelor.
The frequency of MBG 3 was the only reperfusion index that was significantly more prevalent in prasugrel treated group as compared with clopidogrel and ticagrelor groups.