Prognostic significance of serum potassium level for major adverse cardiac events and death in patients with coronary atherosclerotic disease

Introduction: Serum potassium levels have been shown in some animal studies to be associated with the process of atherosclerosis. We decided to assess the correlation of serum potassium level in ischemic heart disease patients with disease severity and its relationship with prognosis in terms of major acute cardiac events (MACE). Material and methods: This was a cross-sectional cohort study carried out at cardiology department of Rehman Medical Institute, from July 2016 to 31st Aug. 2018 a period of 26 months. 622 patients were included in the study. Clinical and angiographic characteristics were assessed based on the serum potassium level. Correlation of serum potassium level with Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) and Gensini scores was also evaluated. Follow up for MACE was carried out after one year. Results: Mean serum potassium level was 3.93 ± 0.95 (mEq/l) in coronary artery disease patients. Serum potassium level showed negative correlation with SYNTAX score (r = –0.60, p < 0.05) and Gensini score (r = –0.64, p < 0.05). There was also a significant difference between low and high potassium level in relation to the multi-vessel disease on coronary angiography (p < 0.05). Low potassium level was a good predictor of adverse outcomes as shown by Kaplan-Meier analysis. Multivariate Cox regression analysis showed that serum potassium level and diabetes were independent predictors of MACE (p < 0.05). Conclusion: Low serum potassium level is correlated with more severe coronary atherosclerosis. Low potassium levels are associated with significantly poor outcomes.