Background:
Immediate percutaneous coronary intervention (PCI) is increasingly performed in comatose survivors of out-of-hospital cardiac arrest (OHCA) undergoing therapeutic hypothermia (TH). Since reported incidence of stent thrombosis (ST) varies significantly from 2.5% to 31%, we investigated definite ST using systematic coronary angiography (CAG) and autopsy.
Methods:
Consecutive comatose survivors of OHCA undergoing immediate PCI and TH admitted between August 2016 and May 2018 were investigated. CAG was performed if ST was suspected and systematically between day 10-14. Patients who died underwent autopsy with analysis of stented segments.
Results:
Among 147 consecutive patients, immediate CAG was performed 103 (70%) and 52 (50%) underwent PCI. Since 5 patients refused to participate or had no follow-up, 47 patients were included. Definite ST, which was confirmed 8 patients (17%), was diagnosed either by clinically-driven CAG (n = 6), routine CAG (n = 1) or autopsy (n = 1). Patients with ST had more often diabetes (38% vs. 5%; p = 0.008), longer interval of prehospital resuscitation (12.6 ± 10.7 minutes vs. 25.0 ± 10.6 minutes; p = 0.005), higher admission lactate (6.8 ± 6.3 mmol/L vs. 3.2 ± 2.9 mmol/L; p = 0.013), lower arterial pH (7.13 + 0.19 vs. 7.27 ± 0.11; p = 0.005) and less favorable survival with good neurological outcome - Cerebral Performance Category score 1 - 2 (13% vs. 62%; p = 0.03). There was no difference in left ventricular ejection fraction (40 ± 12% vs. 39 ± 13%; p = 0.85), periprocedural dose of unfractioned heparin (8944 ± 2504 IU/kg vs. 8188 ± 2764 IU/kg; p = 0.45), use of GP llb/llla (16 % vs. 25 %; p = 0.59) and of novel P2Y12 inhibitor ticagrelor (79% vs. 63%; p = 0.33). There was no significant difference in total length of stented segment (32.7 ± 24.4 mm vs. 36.6 ± 20.7 mm; p = 0.68) nor in average stent diameter (3.1 ± 0.5 mm vs. 3.2 ± 0.4 mm; p = 0.62).
Conclusions:
Incidence of definite ST in comatose survivors of OHCA undergoing immediate PCI and TH is significant (17%) and is associated with worse outcome. Prolonged prehospital resuscitation and diabetes rather than PCI characteristics represent the risk factors for development of ST.
Ticagrelor effectively inhibits platelet aggregation in comatose survivors of cardiac arrest undergoing primary percutaneous coronary intervention treated with mild therapeutic hypothermia
