Relation of baseline serum potassium levels to angiographic findings in patients with known or suspected coronary artery disease.

Background: In experimental animal studies, potassium has been demonstrated to protect against the development of atherosclerosis through a variety of mechanisms. Data regarding the role of potassium in the development of human atherosclerosis are sparse. The objective of this study was to determine the association between plasma potassium levels and angiographically defined coronary artery disease (CAD).

Methods: In a cohort of 389 male patients undergoing coronary angiography for a variety of clinical indications, the association between baseline serum potassium levels and the extent of angiographically defined atherosclerosis was analyzed. Adjustments were made for clinical and laboratory variables (including inflammatory markers) known to be associated with atherosclerosis.

Results: By multivariate logistic regression analysis, baseline serum potassium levels were an independent predictor of the presence of multivessel disease (odds ratio (OR) 1.31, 95% confidence interval (CI) 1.01-1.69; P < 0.05). In addition, in the non-myocardial infarction subpopulation of patients, serum potassium was also an independent predictor of the presence of multivessel disease by multivariate logistic regression analysis (OR 1.34, 95% CI, 1.02-1.76; P < 0.05). In the myocardial infarction (MI) subpopulation, serum potassium was not a predictor of multivessel disease, possibly due to the confounding effect of hypokalemia known to be present during MI.

Conclusions: These data demonstrate that a simple baseline serum potassium level is independently associated with the presence of multivessel disease, even in the context of clinical CAD risk factors and other established inflammatory markers.