Background and aims The mode of death of patients with heart failure (HF) and potassium (K+) disorders remain speculative. To identify the risk factors for development of K+ disorders and recurrence in CHF, and the mode of death associated with K+ disorders.
Methods A retrospective cohort of 10378 outpatients with CHF was studied in a mean follow-up of 3.28±2.5 years. We used the Kaplan Meier method stratified by potassium disorder status; the Cox proportional hazards regression models, adjusting for confouders; the Poisson regression models adjusting for the same covariates; and the e-value determination on the observed associations between and outcomes (e-value >1.6).
Results Chagas etiology (p<0.01) and triple HF therapy (p<0.01) were associated with hyperkalemia. Atrial fibrillation with hypopotassemia (p<0.01). Chronic kidney disease (p<0.01), and diabetes (p=0.03), with both. Hypertension was inversely related to hyperkalemia (p<0.01) while age was inversely related to hypokalemia. Association with mortality was obtained for Chagas etiology (p<0.01, e-value 2.16), stroke (p<0.01, e-value 1.85), hypokalemia (p=0.02, e-value 1.94), and CKD (p<0.01, e-value 1.63 – 4.83). Decompensated HF or cardiogenic shock were causes of death in 54%, 67.8%, 44.9%, 57.8% and 69% of patients with normokalemia, hypokalemia, mild, moderate, and severe hyperkalemia, respectively. Most patients with hypokalemia and severe hyperkalemia died from decompensated HF (p=0.007).
Conclusion Chagas etiology is a new factor associated with hyperkalemia. Unexpectedly progressive HF was the most frequent mode of death in potassium disorders rather that death caused by arrhythmias. Our findings suggest that patients with potassium disorders should be closely monitored and managed to prevent death from cardiogenic shock or decompensated heart failure. Further studies are needed to confirm these findings and to explore the underlying mechanisms involved in the association between potassium disorders and mode of death.
