A model for predicting angiographically normal coronary arteries in survivors of out-of-hospital cardiac arrest.

Background: It has been recommended that all survivors of out-of-hospital cardiac arrest (OHCA) have immediate coronary angiography (CAG), even though it has been reported that half of the survivors have normal coronary arteries. Our aim was to develop a model which might identify those who have angiographically normal coronary arteries. Reliable prediction would reduce unnecessary CAG.

Methods: A retrospective, observational, cohort study was conducted on 47 consecutive adult survivors who received immediate CAG after resuscitation from OHCA, between June 1, 2006 and March 31, 2011. We analyzed the clinical and electrocardiographic characteristics of the survivors with and without normal coronary arteries.

Results: All subjects had CAG. Normal coronary arteries were found in 25/47. These persons did not have diabetes mellitus (p = 0.0069) or a history of acute coronary syndrome (ACS) (p = 0.0069). Any abnormality of the ST segment or ST segment elevation on electrocardiogram (ECG) was strongly related to abnormal coronary arteries (p = 0.0045 and p = 0.0200, respectively). The partitioning model for predicting angiographically normal coronary arteries showed that all patients (8/8) with no ST segment change on their ECG had normal coronary arteries. Eight out of ten patients with ST segment abnormalities also had normal coronary arteries with a history of arrhythmia without a history of ACS.

Conclusions: Survivors of OHCA who have no history of diabetes mellitus, who have no past history of ACS, and who present with no ST segment abnormalities may not require urgent/emergent CAG. Further studies are needed to guide clinicians in the determination of emergent cardiac catheterization following resuscitation of OHCA.