A new trial investigating high-normal serum potassium levels for people at high risk of ventricular arrhythmias delivered promising results.
Compared to a control group, people with these elevated potassium levels fared better over the approximately 3 years of the trial.
Too little potassium is bad for the heart, and so is too much. The trial suggested a new sweet spot for at-risk heart patients.
The study, conducted at three sites in Denmark, was called the POTCAST trial, for “Targeted Potassium Levels to Decrease Arrhythmia Burden in High-Risk Patients with Cardiovascular Diseases.”
The trial tracked for 3.3 years the cardiovascular health of participants maintaining high-normal potassium levels compared to a control group whose potassium levels were not being treated.
This was done by measuring the incidence of specific cardiovascular events: sustained ventricular tachycardia, necessary life-saving ICD therapy, unplanned hospitalization of greater than 24 hours for arrhythmia or heart failure, or death from any cause.
By the end of the trial, just 22.7% of study participants with high-normal potassium levels had experienced one of these events, compared to 29.2% of individuals in the untreated group.
Specifically, just 15.3% of high-normal potassium individuals experienced a ventricular tachycardia event or required ICD therapy, compared to 20.3% of the normal potassium participants, while for the untreated group, 10.7% required hospitalization for arrhythmia, compared to 6.7% of those in the high-normal group.
The target potassium level for the high-normal group in the study was 4.5-5.0 mmol/L (millimoles per liter). The average potassium level of participants at the baseline was 4.01 mmol/L.
The trial aimed to identify an increased level of potassium that was high enough to aid heart function without being so high as to cause damage.
