MedWire News: Heart failure patients with low blood levels of potassium have a greater risk of dying in the long term than those with normal blood levels of the mineral, study results show.

The findings indicate that heart failure patients should be tested for their levels of potassium, and receive supplements if their blood contains low levels of the mineral.

Researchers from the University of Alabama in Birmingham, USA, studied potassium levels in 6845 patients with heart failure.

In total, 1189 patients had low levels of the mineral, defined as being below 4 mEq/l. Over a 10-year period, the researchers compared death rates in these patients with those among an equal number of patients with normal levels of potassium, defined as 4 mEq/l or higher.

They found that 379 patients with normal potassium levels died during this time compared with 441 of those with low potassium levels.

“Our findings showed that heart failure patients with low to low-normal (less than 4 mEq/l) potassium levels were more likely to die than those with higher levels (4 to 5.5 mEq/l) of potassium,” said lead research Dr Ali Ahmed.

“These patients were not significantly more likely to be hospitalised than the higher potassium group, suggesting that most low potassium associated deaths were sudden deaths due to ventricular arrhythmias [heart rhythm problems].”

He concluded: “Our findings suggest that low potassium levels in patients with chronic heart failure should be corrected and potassium should be maintained above 4 mEq/l.”

The research is published in the European Heart Journal.