Postcardioplegia ventricular fibrillation: No impact on subsequent survival

OBJECTIVES: At aortic declamping after cardioplegic cardiac arrest, the initial rhythm can be broadly classified as ventricular fibrillation (VF) or non-VF. VF can be treated with potassium-induced conversion and direct-current countershock is only applied if potassium treatment fails. We aimed to investigate whether there are any differences between these groups of patients in regard to outcomes. DESIGN: From January 1999 through December 2010, 12,113 patients underwent various types of cardiac surgery. Data from every patient were consecutively registered. Survival was established through the Norwegian National Registry. Cox multivariable modeling with adjustment for clinical, biochemical, and medication baseline data was used for survival analysis. RESULTS: The mean follow-up time was 7.4 years and total patient-years were 89,268. The percentage of all-cause deaths was 24.9. Adjusted survival for patients with no postcardioplegia VF (n = 9723) and patients with successful potassium-induced conversion (n = 1877) was completely identical. Four hundred patients with electrical conversion after failed potassium treatment had a nonsignificant trend toward an increased mortality (hazard ratio, 95% confidence interval: 1.19 (0.99-1.4); p = 0.07). CONCLUSIONS: This is the first study reporting the association between postcardioplegia VF, its treatment with potassium and outcome. No impact was found on outcome as judged by all-cause mortality.