Effect of the Timing of Admission of Out of Hospital Cardiac Arrest Complicating Acute Myocardial Infarction on Management and Outcome.

ABSTRACT

There is limited data regarding the impact of time of admission on clinical outcomes of out of hospital cardiac arrest (OHCA) complicating acute myocardial infarction (AMI). We investigated the patient characteristics, management, and outcomes of OHCA complicating AMI according to the time of admission. Patients admitted with a diagnosis of AMI and OHCA between 2010 and 2017 from the Myocardial Ischemia National Audit Project (MINAP) were studied. All patients were stratified into out-of-hours (OOH) and working hours (WH) cohort according to the time of hospital admission. We used multivariable logistic regression models to evaluate the predictors of clinical outcomes and treatment strategy. 16,118 patients were admitted with AMI and OHCA. The WH cohort consisted of 5,780 patients (35.9%) and OOH cohort consisted of 10,338 patients (64.1%). The OOH cohort was younger (OOH 64 vs WH 66 years, p <0.001). A significantly higher proportion of patients had a final diagnosis of STEMI in OOH cohort (OOH 78.3% vs WH 76.6%, p = 0.012). Whilst the use of coronary angiography was lower in OOH (OOH 80.7% vs WH 82.5%, p = 0.005), PCI rates were similar (OOH 39.7% vs WH 40.5%, p = 0.4). Adjusted in-hospital mortality (OR 0.96, 95%CI 0.86 to 1.07), re-infarction (OR 0.90, 95% CI 0.72 to 1.12) and bleeding (OR 0.93, 95% CI 0.76 to 1.12) were similar in the 2 groups. In conclusion, the majority of OHCA occurred out of working hours. However, the time of hospital admission didn't affect the rate of revascularization by PCI or clinical outcomes.