TUESDAY, Jan. 10 (HealthDay News) -- Heart attack patients whose blood potassium levels are within a certain range are less likely to die than those with levels of the mineral below or above that range, says a new study that challenges current recommendations for potassium levels in heart attack patients.
Researchers looked at data from nearly 39,000 heart attack patients admitted to 67 U.S. hospitals between 2000 and 2008. Of those patients, nearly 7 percent died while they were hospitalized.
The death rate for patients with blood potassium levels of between 3.5 and less than 4 mEq/L (milliEquivalents per liter) was 4.8 percent, about the same as the 5 percent death rate among those with levels of 4 mEq/L to less than 4.5 mEq/L.
But mortality rose to 10 percent for those with levels of 4.5 to less than 5 mEq/L, and was even higher for those with levels greater than 5 mEq/L, the investigators found.
Patients with potassium levels of less than 3.5 mEq/L also had a higher death rate than those with levels of between 3.5 and less than 4.5 mEq/L, Dr. Abhinav Goyal, of the Emory Rollins School of Public Health in Atlanta, and colleagues, reported in the study published in the Jan. 11 issue of the Journal of the American Medical Association.
Currently, professional societies and experts recommend that potassium levels in heart attack patients should be maintained between 4.0 and 5.0 mEq/L or even 4.5 to 5.5 mEq/L, the researchers noted.
"In conclusion, our large study of patients with AMI [acute myocardial infarction, or heart attack] challenges current clinical practice guidelines that endorse maintaining serum potassium levels between 4.0 and 5.0 mEq/L," the study authors wrote.
The guidelines are based on small, older studies that focused only on ventricular arrhythmias and not mortality, and were conducted before the routine use of beta-blockers, treatments to quickly clear blockages and res
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