Sudden Cardiac Death Due to Ventricular Arrhythmia in Acute Coronary Occlusion: Potential Roles of the Sinoatrial Nodal Artery and Conus Artery.

Abstract

Background: Despite advances in the management of coronary disease, the incidence of sudden cardiac death (SCD) in the context of coronary artery disease (CAD) remains significant and unpredictable. We investigated the patient and angiographic characteristics, and predictors of long-term outcomes, of patients presenting with cardiac arrest in the context of acute coronary occlusion, to elucidate possible mechanisms of ventricular arrhythmia.

Methods: A total of 127 consecutive patients presenting to a tertiary cardiac centre with pulseless ventricular tachycardia or ventricular fibrillation during acute myocardial infarction (AMI) were compared to 100 patients with uncomplicated AMI (Cohort A). We also compared a separate group comprising 20 patients with acute RCA occlusion complicated by cardiac arrest and 24 patients with uncomplicated inferior STEMI (Cohort B).

Results: In Cohort A, there was a higher incidence of proximal lesions in the arrest group (55% vs. 41%, p < 0.05). There was an almost equivalent incidence of both LAD and non-LAD (RCA/Cx) infarcts presenting with cardiac arrest. In the non-LAD arrest patients, sinoatrial nodal artery (SANa) involvement was seen in 77%, compared with 33% in non-arrest patients (p < 0.005). In Cohort B, involvement of the SANa or conus artery (CA) was found in 74% of arrest versus 21% of non-arrest patients (p < 0.005). Cohort A patients were followed up for 3.8 to 8.7 years, and at the end of this period, 22% of arrest patients and 16% of non-arrest patients were deceased. Mortality <30 days was highest in the arrest group (43% vs. 7%, p < 0.05). Beyond 30 days, there were no differences in all-cause mortality between arrest and non-arrest patients. There were more cardiac causes of death in the arrest group (54% vs. 20%, p < 0.05).

Conclusions: VT/VF arrest due to acute coronary occlusion was more common in those with proximal disease and there was an increased incidence of SANa and/or CA involvement in non-LAD infarcts. Short-term mortality was higher in patients with cardiac arrest post-AMI, but beyond 30 days there was no significant difference.