A comparison of precipitants and mortality when acute decompensated heart failure occurs in the community and hospital settings

Aim: We aimed to compare the precipitants of acute decompensated heart failure (ADHF) among patients admitted with diagnoses inclusive of ADHF (community patients) and patients admitted without ADHF but who developed it during their stay (hospital patients).

Methods: This was a prospective, analytical, observational study undertaken in the Austin Hospital, a major metropolitan teaching hospital (September 2008-February 2010). Consecutive patients admitted to a general medicine unit, and diagnosed and treated for ADHF were enrolled. The unit medical staff completed a specifically designed data collection document.

Results: Three hundred and fifty-nine patients were enrolled (42.9% male, mean age 81.9 years). The community (n=312) and hospital (n=47) patient groups did not differ in age, gender, risk variables (living alone, cognitive impairment, multiple medications, compliance), cardiac failure medication use or cause of known heart failure (ischaemia, hypertension, valve dysfunction, 'other') (p>0.05). The ADHF precipitants comprised infection (39.8% patients), myocardial ischaemia (17.3%), tachyarrhythmia (16.2%), non-compliance with fluid and salt restriction (9.2%), non-compliance with medication (6.7%), renal failure (5.8%), medication reduction (5.0%), intravenous fluid complication (3.9%) and 'other' causes (13.9%). Significantly more hospital patients had their ADHF precipitated by intravenous fluid complications (25.5% versus 0.6%, p<0.001). Hospital patients also had a significantly greater death rate (25.5% versus 9.3%, p<0.01).

Conclusion: Acute decompensated heart failure precipitated in hospital is a dangerous condition with a high mortality. While infection and myocardial ischaemia are the common precipitants, complications of intravenous fluid use, an iatrogenic condition, may be considerable and are potentially avoidable.