Incident Hyperkalemia, Hypokalemia, and Clinical Outcomes During Spironolactone Treatment of Heart Failure With Preserved Ejection Fraction: Analysis of the TOPCAT Trial

Both hyperkalemia and hypokalemia are associated with heightened risk for mortality in HF-PEF. Use of spironolactone in this population requires careful laboratory surveillance of K+ and creatinine, particularly in high-risk groups.