A NEW study presented at the ESC Congress 2024 has revealed that relaxed potassium control, rather than routine supplementation to maintain high-normal levels, is just as effective in preventing atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. The TIGHT-K trial, suggests that the common practice of tight potassium control is unnecessary and costly.
AF occurs in about one in three patients after CABG surgery, leading many centres to supplement potassium to maintain serum levels at the upper limit of normal. However, the TIGHT-K trial, led by Professor Benjamin O’Brien from the Deutsches Herzzentrum der Charité in Berlin, Germany, found that supplementing potassium only when levels dropped below the lower limit of normal was non-inferior to tight control for preventing AF.
The study involved 1,690 patients across 23 centres in the UK and Germany, who were randomly assigned to tight potassium control (supplementation if levels fell below 4.5 mEq/L) or relaxed control (supplementation only if levels fell below 3.6 mEq/L). The primary endpoint was the occurrence of new-onset AF within 120 hours post-surgery or until hospital discharge. The study found no significant difference in AF rates between the groups, with AF occurring in 27.8% of the relaxed control group and 26.2% of the tight control group.
Moreover, relaxed potassium control reduced the number of potassium administrations and associated costs, highlighting the inefficiency of tight control. The study also reported no significant differences in other dysrhythmias, in-hospital and six-month mortality rates, or hospital stay length between the two groups.
The authors concluded by mentioning that their findings indicate that routinely supplementing potassium for tight control offers no benefits but only increases costs and patient discomfort. The TIGHT-K trial shows that we can safely relax potassium control post-CABG, improving patient experience and saving resources.
Aleksandra Zurowska, EMJ
Reference
Campbell NG et al. Impact of maintaining serum potassium concentration ≥3.6mEq/L versus ≥4.5mEq/L for 120 hours after isolated coronary artery bypass graft surgery on incidence of new onset atrial fibrillation: protocol for a randomized non-inferiority trial. PLoS ONE. 2024;19:e0296525.
