The impact of infections on critically ill acute heart failure patients: an observational study.

BACKGROUND: Hospitalised patients with acute heart failure (AHF) suffer from a high morbidity and mortality, which might, at least partly, be influenced by concomitant infections. The aim of this observational study was to investigate the impact of infections on the clinical course of critically ill patients with AHF, both present on intensive care unit (ICU) admission and acquired during the ICU stay. METHODS: From 178 consecutive AHF patients, 76 were treated medically and 21 required emergency cardiac surgery. The remaining 81 patients, who underwent elective cardiac surgery, were excluded from the assessment of infections on ICU admission, but were included in the analysis of nosocomial infections during the ICU stay. RESULTS: A total of 16% of patients (16/97) had infections on ICU admission. These patients had longer ICU (6 vs. 3 days, p = 0.04) and hospital (19 vs. 11 days, p = 0.04) stays than patients without infections. Although not statistically significant, there was a trend for increased mortality at 30 days (44% vs. 24%, p = 0.13) and 6 months (57% vs. 31%, p = 0.13) in AHF patients with infections on ICU admission. Infection complications during the ICU stay occurred in 17% (30/178) of AHF patients and significantly increased their mortality at 30 days (33% vs. 14%, p = 0.02) and 6 months (41% vs. 18%, p = 0.02). CONCLUSIONS: In this observational study, infections present on ICU admission or occurring during the ICU stay had a negative impact on the morbidity and mortality of critically ill patients with AHF. Future studies are needed to gain a better understanding of the interactions between heart failure and infections, as a better knowledge of this field may have an important therapeutic potential.

Presentation and outcome of critically ill medical and cardiac-surgery patients with acute heart failure.

BACKGROUND: The aim of the study was to investigate presentation and outcome of consecutive acute heart failure (AHF) patients admitted to the intensive care unit (ICU) including also patients undergoing cardiac surgery, thereby providing comparative information on all critically ill AHF subgroups. METHODS: The prospective observational study with 6-month follow up was performed in the cardio-thoracic and the medical ICU of a university hospital. AHF was defined according to the European Society of Cardiology guidelines. Univariate Cox regression was used to calculate hazard ratio (HR) and 95% confidence intervals (CI) for risk factors. RESULTS: A total of 192 patients fulfilled the AHF criteria, of whom 86 and 24 underwent elective and emergency cardiac surgery, respectively. The remaining 82 medical patients had no surgical interventions. Cardiogenic shock was diagnosed in 32% of all patients and was the most common AHF presentation. Medical, elective surgery and emergency surgery AHF patients had a mortality at 30 days of 31%, 4.7% and 22% (<0.05) and at 180 days of 42%, 6.1% and 23% (<0.05), respectively. While the presence of cardiogenic shock was associated with a poor outcome (HR 1.8, CI 1.0-3.0; p=0.04), post-operative cardiac stunning had a good prognosis (HR 0.06, CI 0.01-0.47; p<0.01). Mortality worsened when infections (HR 2.8, CI 1.5-5.7; p<0.01) or renal dysfunction (HR 4.4, CI 2.2-8.4, p<0.01) were present on ICU admission. CONCLUSIONS: Medical patients, patients undergoing elective cardiac surgery and patients requiring emergency cardiac surgery are three distinct AHF-subpopulations. Co-morbidities and surgical treatment options affect long-term outcome.