Data from the 2012 European Cardiovascular Disease Statistics show that 20% of all deaths are caused by coronary artery disease (CAD), with cardiac arrest (CA) as the most common scenario.1 Historic angiography data have shown that CAD was present in approximately 70% of unselected out-of-hospital CA (OHCA) patients.2 As registry and retrospective data are prone to bias, it remains unknown whether an early invasive strategy translates into improved outcome; therefore, the authors present their experience from a large urban region of Denmark.
The purpose of the study was to describe a consecutive OHCA-cohort with regards to incidence of CAD, comorbidity, and survival rate. The authors consecutively included patients from an unselected cohort with OHCA in the capital region of Denmark (N=1,003) from 2007 to 2011. After successful resuscitation, patients were admitted for post-resuscitation care at 1 of 8 hospitals, including coronary angiography and percutaneous coronary interventions (PCI), when indicated.
Patients were found to be 65±15 years of age, 71% were male, 52% had shockable primary rhythm, and the median time to return of spontaneous circulation was 22 minutes (Q1–Q3: 13–37 minutes). Furthermore, the majority was unconscious at hospital admission (89%), and no previous comorbidity was noted in 38% of the patients. The majority of the cohort had OHCA due to a cardiac cause (n=806; 80%). According to angiography evaluation, 75% of the cohort had CAD, and acute coronary syndrome (ACS) was diagnosed in 39% of the total cohort (n=389). In 48% of patients with cardiac cause with ST-segment elevation, myocardial infarction was more frequent (n=236; 60% of ACS).
The authors found 30-day mortality rates in 59% of the total cohort and 46% in patients with ACS (plogrank<0.001). A favourable neurological outcome (Cerebral Performance Category of 1 or 2) was noted in 84% of all patients discharged alive (n=347), and in 85% of patients with ACS (n=178).
In the total cohort, ACS was independently associated with a lower 30-day mortality rate (hazard ratio [HR]: 0.62; 95% confidence interval [CI]: 0.51–0.75; p<0.001) after adjustment for age, pre-hospital OHCA circumstances (bystander cardiopulmonary resuscitation, public arrest, and witnessed arrest), time to return of spontaneous circulation, primary admission to a tertiary heart centre, and degree of comorbidity. In OHCA-patients with ACS only, successful PCI was independently associated with a lower 30-day mortality after adjustment for the mentioned prognostic factors (HRall ACS:0.46; 95% CI: 0.31–0.67; p<0.001, HRSTEMI:0.43; 95% CI: 0.27–0.69; p<0.001, HRNSTEMI:0.12; 95% CI: 0.03–0.51; p=0.004).
This data showed that in an unselected clinical cohort of OHCA survivors, CAD was common, and less than half of the patients were diagnosed with ACS. Furthermore, ACS was associated with a better prognosis even after adjustment for prognostic factors. Likewise, successful PCI was an independent prognostic factor; however, this may be attributable to selection bias and a direct support of early invasive strategy in all OHCA-survivors, which was not supported by clinical data. Due to the high grade of CAD, all OHCA-survivors without an obvious non-cardiac cause should have an angiography performed prior to hospital discharge.