AIMS - The aim of the current study was to investigate the impact of a chronic total occlusion (CTO) in a non-infarct-related coronary artery (non-IRA) on one-year mortality and occurrence of cardiac arrhythmia in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI).

METHODS AND RESULTS - In a retrospective sub-analysis of the Intraaortic Balloon Pump in Cardiogenic Shock II trial (IABP-SHOCK II) and its accompanying registry, 201 (26%) of 761 patients had a CTO in a non-IR major coronary artery. Mortality was significantly higher in the CTO group at day of admission (19% vs. 11%; p=0.005), 30 days (53% vs. 41%, p=0.002), and 12 months (63% vs. 51%, p=0.002). In the adjusted multivariate Cox regression analysis, a CTO in a non-IRA was an independent predictor of mortality at 12 months (hazard ratio 1.30, 95% confidence interval [CI]: 1.02-1.67, p=0.03). At 30-day follow-up, ventricular arrhythmias requiring defibrillation occurred more frequently in patients with non-IRA CTO in the univariate analysis (33% vs. 21%, odds ratio 1.83, 95% CI: 1.28-2.62, p=0.002).

CONCLUSIONS - In patients with CS complicating AMI, the presence of CTO in a non-IRA is associated with a higher incidence of ventricular arrhythmias and is an independent predictor of mortality at 12-month follow-up.