Serum magnesium aberrations in furosemide (frusemide) treated patients with congestive heart failure: pathophysiological correlates and prognostic evaluation
Open Access
- 1 April 2003
- Vol. 89 (4), 411-416
- https://doi.org/10.1136/heart.89.4.411
Abstract
Objectives: To determine the prevalence of hypomagnesaemia and hypermagnesaemia, to discern various factors associated with abnormal serum magnesium, and to estimate prognostic significance of serum magnesium aberrations in patients with congestive heart failure. Design: Observational study. Setting: Medical department of a university hospital (tertiary referral centre). Patients: 404 consecutive patients admitted with congestive heart failure as one of the diagnoses and previously treated with furosemide (frusemide) for at least three months. Main outcome measures: Clinical, biochemical, and electrocardiographic variables were analysed with respect to serum magnesium aberrations. Following discharge, mortality rates, including sudden death, were registered. Results: Hypomagnesaemia was found in 50 patients (12.3%) and 20 (4.9%) were hypermagnesaemic. Female sex (p < 0.04), diabetes mellitus (p < 0.006), hypocalcaemia (p = 0.03), hyponatraemia (p < 0.05), malignant disease (p = 0.05), and high fever (p = 0.05) were statistically associated with hypomagnesaemia. Renal failure, severe congestive heart failure, and high dose furosemide treatment (> 80 mg/day) were associated with hypermagnesaemia (p < 0.001, p = 0.05, and p < 0.03, respectively). Hypermagnesaemic patients were older and weighed less. On follow up (median duration 43 months), 169 (41.8%) died, with 22 (13%) sudden deaths. Mortality was highest with hypermagnesaemia, lowest with normomagnesaemia, and intermediate with hypomagnesaemia. After adjustment for renal failure, old age, and severity of congestive heart failure, hypomagnesaemia but not hypermagnesaemia emerged as being significantly associated with shorter survival (p = 0.009). No statistical association was found between sudden death and magnesium concentrations. Conclusions: While hypermagnesaemia seems to represent a prognostic marker only, hypomagnesaemia appears to have an adverse pathophysiological effect. The subgroup of patients at risk for hypomagnesaemia requires frequent serum magnesium determinations and magnesium replacement for as long as hypomagnesaemia persists.Keywords
This publication has 32 references indexed in Scilit:
- The Effect of Spironolactone on Morbidity and Mortality in Patients with Severe Heart FailureNew England Journal of Medicine, 1999
- Significance of magnesium in congestive heart failureAmerican Heart Journal, 1996
- Clinical relevance and management of the major electrolyte abnormalities in congestive heart failure: Hyponatremia, hypokalemia, and hypomagnesemiaAmerican Heart Journal, 1994
- Female gender as a risk factor for torsades de pointes associated with cardiovascular drugsJAMA, 1993
- Effects of long-term oral magnesium chloride replacement in congestive heart failure secondary to coronary artery diseaseThe American Journal of Cardiology, 1993
- Electrolyte balance in heart failure and the role for magnesium ionsThe American Journal of Cardiology, 1992
- Importance of magnesium in congestive heart failureThe American Journal of Cardiology, 1989
- Magnesium metabolism. A review with special reference to the relationship between intracellular content and serum levelsArchives of Internal Medicine, 1988
- Plasma and Skeletal Muscle Electrolytes in Patients on Long‐term Diuretic Therapy for Arterial Hypertension and/or Congestive Heart FailureActa Medica Scandinavica, 1987
- Effects of magnesium sulfate on cardiac conduction and refractoriness in humansJournal of the American College of Cardiology, 1986