P329Residual platelet reactivity after pre-treatment with ticagrelor prior to primary percutaneous coronary intervention is associated with suboptimal myocardial reperfusion

Abstract

Abstract Background The evidence of a clinical benefit of P2Y12 inhibitor pre-treatment in primary percutaneous coronary intervention (PCI) and the relation between the level of platelet inhibition and myocardial reperfusion with newer potent P2Y12 inhibitors remain unclear. Objectives We aimed to assess the relationship between platelet reactivity at the time of primary PCI after pre-treatment with aspirin and ticagrelor and the post-PCI myocardial blush grade (MBG). Methods We prospectively included 61 patients. Platelet reaction units for ticagrelor (PRU) and aspirin reaction units (ARU) were measured using the point-of-care test VerifyNow before PCI. The high on-ticagrelor (PRU >208) and on-aspirin (ARU ≥550) platelet reactivity (HPR and HaPR) were assessed. Patients were divided into two groups according to MBG 3 or <3. Results MBG 3 was identified in 28 (46%) patients. Mean PRU was lower in such patients as compared to those with MBG <3 (155.82±90.91 vs 227.42±65.18; p=0.001) while mean ARU was similar between groups. HPR and HaPR were observed in 30 (49.2%) and 11 patients (18%), respectively. HPR but not HaPR was more frequent in the group with impaired MBG (66.7 vs 28.6%; p=0.003 and 21.2 vs 14.3%; p=0.48 respectively). Table 1. Platelet reactivity results Verify Now at admission All Final Blush <3 Final Blush 3 p n=61 (100%) n=33 (54%) n=28 (46%) PRU P2Y12 194.56±85.32 227.42±65.18 155.82±90.91 0.001 Base 193.54±49.01 194.79±45.68 192.07±53.48 0.83 Inhibition of platelet aggregation (%) 15.61±29.85 5.7±17.55 27.29±36.79 0.007 ARU 463.97±76.45 472.58±72.5 453.82±81 0.34 PRU >208 30 (49.1%) 22 (66.7%) 8 (28.6%) 0.003 ARU ≥550 11 (18%) 7 (21.2%) 4 (14.3%) 0.48 Verify Now at day 1 n=57 n=30 n=27 p PRU P2Y12 40.86±41.43 47.27±45.87 33.74±35.35 0.21 Base 196.98±36.19 193.67±30.67 200.81±41.97 0.47 Inhibition of platelet aggregation (%) 79.8±17.96 76.37±20.54 83.77±13.78 0.11 ARU = Aspirin reaction units; PRU = P2Y12 reaction units. Conclusion In conclusion, our study shows that higher PRU and the subsequent HPR at the time of primary PCI, after pretreatment with ticagrelor, are the only correlates of post PCI MBG. These findings support the earliest possible loading with ticagrelor prior to primary PCI. Acknowledgement/Funding The study was supported by grants from Terumo. The funder has no role in any step of the study.