Acute precipitants of congestive heart failure exacerbations

Background: Few studies have prospectively and systematically explored the factors that acutely precipitate exacerbation of congestive heart failure ( CHF) in patients with left ventricular dysfunction. Knowledge of such facto rs is important in designing measures to prevent deterioration of clinical status. The objective of this study was to prospectively describe the preci pitants associated with exacerbation of CHF status in patients enrolled in the Randomized Evaluation of Strategies for Left Ventricular Dysfunction Pi lot Study. Methods: We conducted a 2-stage, multicenter, randomized trial in 768 patie nts with CHF who had an ejection fraction of less than 40%. Patients were r andomly assigned to receive enalapril maleate, candesartan cilexetil, or bo th for 17 weeks, followed by randomization to receive metoprolol succinate or placebo for 26 weeks. Investigators systematically documented informatio n on clinical presentation, management, and factors associated with the exa cerbation for any episode of acute CHF during follow-up. Results: A total of 323 episodes of worsening of CHF occurred in 180 patien ts during 43 weeks of follow-up; 143 patients required hospitalization, and 5 died. Factors implicated in worsening of CHF status included noncomplian ce with salt restriction (22%); other noncardiac causes (20%), notably pulm onary infectious processes; study medications (15%); use of antiarrhythmic agents in the past 48 hours (15%); arrhythmias (13%); calcium channel block ers (13%); and inappropriate reductions in CHF therapy (10%). Conclusions: A variety of factors, many of which are avoidable, are associa ted with exacerbation of CHF. Attention to these factors and patient educat ion are important in the prevention of CHF deterioration.