Early coronary revascularization improves 24h survival and neurological function after ischemic cardiac arrest. A randomized animal study.

Background: Survival after out-of-hospital cardiac arrest (OHCA) remains poor. Acute coronary obstruction is a major cause of OHCA. We hypothesize that early coronary reperfusion will improve 24h-survival and neurological outcomes.

Methods: Total occlusion of the mid LAD was induced by balloon inflation in 27 pigs. After 5min, VF was induced and left untreated for 8min. If return of spontaneous circulation (ROSC) was achieved within 15min (21/27 animals) of cardiopulmonary resuscitation (CPR), animals were randomized to a total of either 45min (group A) or 4h (group B) of LAD occlusion. Animals without ROSC after 15min of CPR were classified as refractory VF (group C). In those pigs, CPR was continued up to 45min of total LAD occlusion at which point reperfusion was achieved. CPR was continued until ROSC or another 10min of CPR had been performed. Primary endpoints for groups A and B were 24-h survival and cerebral performance category (CPC). Primary endpoint for group C was ROSC before or after reperfusion.

Results: Early compared to late reperfusion improved survival (10/11 versus 4/10, p=0.02), mean CPC (1.4±0.7 versus 2.5±0.6, p=0.017), LVEF (43±13 versus 32±9%, p=0.01), troponin I (37±28 versus 99±12, p=0.005) and CK-MB (11±4 versus 20.1±5, p=0.031) at 24-h after ROSC. ROSC was achieved in 4/6 animals only after reperfusion in group C.

Conclusions: Early reperfusion after ischemic cardiac arrest improved 24h survival rate and neurological function. In animals with refractory VF, reperfusion was necessary to achieve ROSC.