Objectives: This observational study was done to describe the long term prognosis of patients presenting to an emergency room with decompensated heart failure and to determine the factors that influence their survival.
Design: The routine clinical and laboratory characteristics of consecutive patients presenting to an emergency room with decompensated heart failure were documented and the patients followed for an average of 44 months (range 41 to 47).
Setting: One teaching hospital and one community-based hospital in Montreal, Quebec.
Patients: A prospective cohort of 153 consecutive patients presenting to the emergency room with decompensated heart failure.
Outcome measures: Total mortality was the main outcome. Survival status was validated by the government health insurance board.
Results: Survival was poor, with 61% dying within the 47-month follow-up. Univariate analysis revealed the following variables to be associated with decreased survival; low sodium (P < 0.001), decreased renal function (P < 0.001), prior hospitalization for decompensated heart failure (P < 0.001), intraventricular conduction defect (P < 0.002), failure despite prior use of angiotensin-converting enzyme (ACE) inhibitors (P < 0.005) and increased cardiac dimensions as determined by increased left ventricular end systolic diameter (P < 0.04). The multivariate analysis using the Cox proportional hazards model showed a prior admission for heart failure (relative risk [RR] 1.9 [P = 0.005], 95% confidence interval [CI] 1.2 to 2.9), hyponatremia (RR 2.1 [P = 0.005], 95% CI 1.2 to 3.5), presence of an intraventricular conduction delay (RR 1.9 [P = 0.003], 95% CI 1.2 to 2.9), and the cumulative required dose of intravenous furosemide (RR 1.7 [P = 0.03], 95% CI 1.1 to 2.8) to be associated with increased mortality. Patients with hyponatremia despite the use of ACE inhibitors were at greatest risk (RR 11.5 [P < 0.001], 95% CI 5.3 to 24.9).
Conclusions: This prospective observational study confirms that the long term prognosis of patients needing hospitalization for congestive heart failure remains poor. Readily available acute-phase clinical variables may assist in predicting prognosis.