Short-term prognosis of normalising serum potassium following an episode of hypokalaemia in patients with chronic heart failure

It is well known that patients with chronic heart failure and hypokalaemia have increased mortality risk. We investigated the impact of normalising serum potassium following an episode of hypokalaemia on short-term mortality among patients with chronic heart failure. We identified 1673 patients diagnosed with chronic heart failure who had a serum potassium measurement under 3.5 mmol/l within 14 days and one year after initiated medical treatment with both loop diuretics and angiotensin-converting enzyme inhibitors or angiotensin-II receptor blockers. A second serum potassium measurement was required 8-30 days after the episode of hypokalaemia. All-cause mortality and cardiovascular mortality was examined within 90 days from the second serum potassium measurement. Mortality was examined according to six predefined potassium groups derived from the second measurement: