Narrow Window for Optimal Potassium Levels
The difference in potassium levels between the tight-control group and the relaxed-control group were modest in this study, said Subodh Verma, MD, a cardiac surgeon at St Michael’s Hospital and professor at the University of Toronto, Ontario, Canada.
However, this is unavoidable and central to the question being posed, Dr. O’Brien pointed out. Because of the risks for both hypokalemia and hyperkalemia, the window for safe supplementation is short. Current practice is to achieve high-normal levels to reduce atrial fibrillation, but TIGHT-K demonstrates this has no benefit.
The conclusion of TIGHT-K is appropriate, said Faiez Zannad, MD, PhD, professor of therapeutics in the Division of Cardiology at the University of Lorraine in Nancy, France, who praised the design and conduct of the study.
He acknowledged an unmet need for effective methods to reduce the risk for atrial fibrillation after cardiac surgery, but the ESC invited discussant said it is now necessary to look at other strategies. Several are under current evaluation, such as supplementary magnesium and the use of sodium-glucose transporter-2 inhibitors.
Although Dr. Zannad encouraged more studies of methods to reduce atrial fibrillation risk after cardiac surgery, he said that TIGHT-K has answered the question of whether potassium supplementation is beneficial.
Potassium supplementation should no longer be offered, he said, which will “reduce healthcare costs and decrease patient risk from an unnecessary intervention.”
A version of this article first appeared on Medscape.com.