Dyskalemias and adverse events associated with discharge potassium in acute myocardial infarction

Abstract Background The incidence of dyskalemias and associated outcomes in acute myocardial infarction (AMI) are unknown in real-world settings and likely differ from the controlled environment of randomized controlled trials. Methods We examined consecutive survivors of an AMI during 2006-2011 in SWEDEHEART registry and with plasma potassium at discharge (exposure). Study outcomes were 1-year risk of hyperkalemia (potassium >5.0 mmol/L), hypokalemia (potassium Results We included 4,861 patients (65% male, age 71.4 ± 12.6 years) with mean discharge potassium of 4.0 ± 0.4 mmol/L. Within 1 year, 784 (16.1%) new hyperkalemic and 991 (20.4%) new hypokalemic events occurred. Discharge potassium and kidney dysfunction were independent predictors of their occurrence. Compared with discharge potassium of 4.0 to  5.0 mmol/L; the adjusted risk of incident hypokalemia was 1.43 for potassium of 3.5 to 4.5 mmol/L. No association was found between discharge potassium and the risk of new myocardial infarction, heart failure, or de novo atrial fibrillation. Conclusions Among real-world AMI survivors, both hyperkalemia and hypokalemia are frequent. Discharge potassium and kidney function strongly predicted their occurrence, as well as the 1-year risk of death.