Ten-year experience of an invasive cardiology centre with out-of-hospital cardiac arrest patients admitted for urgent coronary angiography.

Background And Aim: The aim of the study was to evaluate survival and neurological function of out-of-hospital cardiac arrest (OHCA) patients admitted for urgent coronary angiography (UCA) with a view to percutaneous coronary intervention (PCI).

Methods: Hospital records of OHCA patients admitted to an invasive cardiology centre (providing 24 h a day/7 days a week service) in 2000-2010 were reviewed retrospectively, and similar data collected in 2011 were reviewed prospectively. Reports from the pre-hospital phase from emergency medical services (EMS) in Krakow were also analysed. Long-term follow-up data were collected by retrieving records from other hospitals (for patients transferred after UCA/PCI) and by phone calls to patients or their relatives.

Results: In 2000-2011, 405 OHCA patients were admitted for UCA/PCI. Most (78%) had ventricular fibrillation (VF) or ventricular tachycardia (VT) as the primary mechanism of cardiac arrest (asystole: 13%, pulseless electrical activity: 3%, unknown: 6%). The mean patient age was 61 (range 20-85) years, and 81% were males. On admission, about 70% of patients were unconscious and 11% were in cardiogenic shock. The mean resuscitation time (time to return of spontaneous circulation [ROSC]) was 26.7 (range 1-126) min. ST-T changes seen in an electrocardiogram recorded after ROSC included ST elevation and depression in 52% of cases, only ST depression in 21% of cases, only ST elevation in 17% of cases, unspecific changes (due to intraventricular conduction disturbances) in 7% of cases, negative T waves in 3% of cases, and no changes in 0.5% of cases. Coronary angiography revealed acute coronary occlusion in 48% of cases, critical coronary stenosis (> 90%) in 26% of cases, other significant coronary lesions (> 50% stenosis) in 15% of cases, and non-significant lesions in 11% of cases. An acute coronary syndrome (ACS) was diagnosed in 82% of patients (75% STEMI, 25% NSTEMI), and other cardiac cause (mostly ischaemic cardiomyopathy) was identified in 13% of patients. Among OHCA patients diagnosed with ACS, PCI was performed in 90% and additional 4% underwent coronary artery bypass grafting. Overall success rate of PCI, defined as TIMI 3 flow plus residual stenosis < 50% and resolution of ST elevation after PCI by > 30%, was 70%. Survival to hospital discharge in the entire group of OHCA patients was 63% and 30-day survival with good neurological outcomes (defined as Cerebral Performance Category 1 or 2) was 49%. Among patients who were initially unconscious, those figures were 52% and 33%, respectively. During long-term follow-up (up to 12 years), 49% of patients were alive and 42% had good neurological function (87% of those who survived). In multivariate analysis, independent predictors of survival with good neurological outcomes were preserved consciousness on admission, absence of shock, cardiac arrest witnessed by medical personnel, VF/VT as a primary mechanism of cardiac arrest, and preserved renal function. Successful PCI predicted survival until hospital discharge only when the neurological status of the patients was not taken into account.

Conclusions: The most important cause of OHCA is coronary artery disease, in particular ACS. UCA and PCI seem to be important elements of appropriate post-resuscitation care because such treatment could improve survival but it is still unclear whether PCI might influence neurological outcomes as well.