Potassium Levels After Acute Myocardial Infarction—Reply

In Reply: Dr Robey highlights the challenges of interpreting population-based research and the need to individualize the treatment of hypokalemia or hyperkalemia based on the patient's underlying pathophysiology. Current practice guidelines¹ based on small, observational studies recommend maintenance of normal potassium levels, in particular among patients with significant ventricular ectopy. Despite a lack of compelling clinical data, many hospitals routinely implement automated algorithms for potassium supplementation that target potassium levels above 3.5 or 4.0 mEq/L in a broad range of hospitalized patients, including those presenting with AMI. Thus, the widespread assumption that routine potassium repletion is medically necessary persists, and achieving these targets requires significant resources. The report by Goyal et al² is one of the largest studies to evaluate the relationship between potassium level and outcomes in AMI. Despite the inherent limitations of any observational, population-based study, the findings from Goyal et al are a substantial step forward from the previous small reports and should remind clinicians of the value of reevaluating habitual clinical practices based on sparse data.