Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Jun;28(11):1334-43.
doi: 10.1093/eurheartj/ehm091.

A propensity-matched study of the association of low serum potassium levels and mortality in chronic heart failure

Ali Ahmed  1 , Faiez Zannad, Thomas E Love, Jose Tallaj, Mihai Gheorghiade, Olaniyi James Ekundayo, Bertram Pitt
Affiliations

A propensity-matched study of the association of low serum potassium levels and mortality in chronic heart failure

Ali Ahmed et al. Eur Heart J. 2007 Jun.

Abstract

Aims: Potassium homeostasis is essential for normal myocardial function, and low serum potassium may cause fatal arrhythmias. However, the association of low potassium and long-term mortality and morbidity in heart failure (HF) is largely unknown.

Methods and results: We studied 6845 HF patients in the Digitalis Investigation Group trial with serum potassium levels < or =5.5 mEq/L. Of these, 1189 had low potassium (<4 mEq/L). Propensity scores for low potassium were calculated for each patient and were used to match 1187 low-potassium patients with 1187 normal-potassium (4-5.5 mEq/L) patients. Effects of low potassium on outcomes were assessed using matched Cox regression analyses. All-cause mortality occurred in 379 (rate, 1103/10 000 person-years) normal-potassium and 441 (rate, 1330/10 000 person-years) low-potassium patients, respectively, during 3437 and 3315 years of follow-up [hazard ratio (HR), 1.25; 95% confidence interval (CI), 1.07-1.46; P = 0.006]. Cardiovascular mortality occurred in 297 (864/10 000 person-years) normal-potassium and 356 (1074/10 000 person-years) low-potassium patients (HR, 1.27; 95% CI, 1.06-1.51; P = 0.009). Cardiovascular hospitalization occurred in 610 (rate, 2553/10 000 person-years) normal-potassium and 637 (rate, 2855/10 000 person-years) low-potassium patients (HR, 1.13; 95% CI, 0.99-1.29; P = 0.082).

Conclusion: In a cohort of ambulatory chronic systolic and diastolic HF patients who were balanced in all measured baseline covariates, serum potassium <4 mEq/L was associated with increased mortality, with a trend towards increased hospitalization.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: None

Figures

Figure 1
Figure 1
Absolute standardized differences in covariates between patients with normal and low serum potassium, before and after propensity score matching
Figure 2
Figure 2
Kaplan-Meier plots for mortality due to (a) all-causes, (b) cardiovascular causes, and (c) worsening heart failure
Figure 3
Figure 3
Hazard ratio and 95% confidence interval (CI) for all-cause mortality associated with low serum potassium in subgroups of patients with chronic heart failure
See this image and copyright information in PMC

References

    1. Macdonald JE, Struthers AD. What is the optimal serum potassium level in cardiovascular patients? J Am Coll Cardiol. 2004;43:155–161. - PubMed
    1. Young DB. Potassium depletion and diastolic dysfunction. Hypertension. 2006;48:201–202. - PubMed
    1. Cooper HA, Dries DL, Davis CE, Shen YL, Domanski MJ. Diuretics and risk of arrhythmic death in patients with left ventricular dysfunction. Circulation. 1999;100:1311–1315. - PubMed
    1. Multiple Risk Factor Intervention Trial Research Group. Multiple risk factor intervention trial, risk factor changes and mortality results. JAMA. 1982;248:1465–1477. - PubMed
    1. Siscovick DS, Raghunathan TE, Psaty BM, Koepsell TD, Wicklund KG, Lin X, Cobb L, Rautaharju PM, Copass MK, Wagner EH. Diuretic therapy for hypertension and the risk of primary cardiac arrest. N Engl J Med. 1994;330:1852–1857. - PubMed

Publication types