Retrospective analysis of the influence of hyponatremia on prognosis in hospitalized patients with chronic heart failure / 中华老年医学杂志

ABSTRACT

Objective To analyze the influence of hyponatremia on hospitalization days and hospital mortality of hospitalized patients with chronic heart failure. Methods All data were collected from 2465 patients with chronic heart failure in our hospital between January 1980 and August 2007. According to the admission serum sodium, all the patients were divided into two groups low serum sodium group (Na+<135 mmol/L) and normal serum sodium group (Na+≥135retool/L). Clinical characteristics, therapeutic conditions and the influence of hyponatremia on prognosis were analyzed between the two groups. Results There were 618 patients in low serum sodium group among 2465 cases. Patients with hyponatremia were more likely to have lower systolic blood pressure and lower left ventricular ejection fraction. Lower admission serum sodium was related with higher concentration of serum angiotensin, aldosterone and higher activity of serum renin. Patients in low serum sodium group had significantly longer hospitalization days (Z=-4.026, P<0.01) and higher rate of hospital mortality (χ2=76.935, P<0.01) than patients in normal serum sodium group. Multivariate logistic regression indicated that lower admission serum sodium was an independent risk factor for hospitalization days (b= 0.928, P<0.01) and hospital mortality (OR=0.928, P<0.01). There was a negative correlation between admission serum sodium and hospitalization days (r=-0.132, P<0.01), and the rate of hospital mortality increased by 24.7for each 3 mmol/L decrease in admission serum sodium level. Conclusions Hyponatremia in hospitalized patients with chronic heart failure is relatively common and is associated with poorer heart function, higher activity of neural hormone and more severe prognosis. It is important to prevent hyponatremia for shortening hospitalization days and improving the prognosis of patients with chronic heart failure.