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

Abstract

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 5 minutes, VF was induced and left untreated for 8 minutes. If return of spontaneous circulation (ROSC) was achieved within 15 minutes (21/27 animals) of cardiopulmonary resuscitation (CPR), animals were randomized to a total of either 45 minutes (group A) or 4 hours (group B) of LAD occlusion. Animals without ROSC after 15 minutes of CPR were classified as refractory VF (group C). In those pigs, CPR was continued up to 45 minutes of total LAD occlusion at which point reperfusion was achieved. CPR was continued until ROSC or another 10 minutes of CPR had been performed. Primary endpoints for groups A and B were 24-hour 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-hr 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.

Synchronized Pulsatile Flow With Low Systolic Output From Veno‐Arterial Extracorporeal Membrane Oxygenation Improves Myocardial Recovery After Experimental Cardiac Arrest in Pigs

“…Due to the short vaECMO treatment in our study, this complication could not be evaluated. Our study included animals with “healthy” hearts and artificially induced CA which does not reproduce the exact conditions of human CA, usually associated with myocardial infarction or chronic ischemic and nonischemic heart disease . Our model investigated the issue of myocardial stunning after CA avoiding complex models including myocardial infarction to avoid difficulties in measuring LVEF due to regional wall motion abnormalities and individual variability in infarct size between pigs.…”

Role of Epinephrine and Extracorporeal Membrane Oxygenation in the Management of Ischemic Refractory Ventricular Fibrillation

“…Further, presence of arterial occlusion influences ROSC rate (19) . Timing of coronary reperfusion and resulting degree of myocardial damage also potentially influence subsequent left ventricular functional recovery 19 , 20 .…”

“…Prolonged CPR (45 min) was associated with a very low ROSC rate in the ECMO− group. Prolonged CPR combined with coronary ischemia decreases the probability of ROSC in humans 20 , 21 . The significant ROSC rate and subsequent survival advantage in the ECMO+ group seen in our study supports the use of ECMO-facilitated PCI compared with CPR-facilitated PCI.…”

Contemporary Management of Out-of-hospital Cardiac Arrest in the Cardiac Catheterisation Laboratory: Current Status and Future Directions

“…The benefits of restoration of coronary flow in this setting have been indicated in large animal studies. [126] Current guidelines recommend emergency PCI for an acute occlusion, the presence of thrombus or abnormal flow, and these findings should, where appropriate, be correlated with ECG and echocardiography. [28] The relative effects of acute plaque rupture and associated ischaemia in the pathophysiology of OHCA remain unclear.…”