Clinical characteristics and predictors of in−hospital mortality in 270 consecutive patients hospitalised due to acute heart failure in a single cardiology centre during one year

Abstract

Background: Acute heart failure (HF) is an emerging problem in clinical practice, associated with high in-hospital mortality and a high short-term readmission rate.
Aim: To describe the clinical characteristics and define predictors of in-hospital mortality in patients with acute HF.
Methods: We conducted a prospective registry of all consecutive patients hospitalised due to acute HF from October 2008 to November 2009 in a single cardiology centre. Clinical status and laboratory parameters were analysed on admission and after 48 h. Results: We examined 270 patients (age 68 ± 13 years, 71% men, 27% with de novo acute HF, 55% with ischaemic aetiology, 56% with decompensated chronic HF, 80% with warm-wet haemodynamic profile). In-hospital mortality was 8.5% (n = 23). There were no differences between survivors vs non-survivors regarding age, gender, HF aetiology, prevalence of de novo acute HF, and baseline heart rate and body weight values and changes of these parameters during hospitalisation (p > 0.2 for all comparisons). Cardiogenic shock and isolated right-sided HF were more common in patients who died as compared to survivors (17% vs 1% and 22% vs 2%, respectively; p < 0.001), as were the cold-wet and cold-dry haemodynamic profiles (22% vs 2% and 17% vs 1%, respectively; p < 0.001). The most common factor precipitating decompensation in non-survivors was an acute coronary syndrome (17% vs 7%), while elevation of blood pressure and inadequate diuretic therapy were the most common causes of acute HF in survivors (26% vs 4% and 45% vs 22%, respectively; p < 0.05). Baseline mean blood pressure and serum Na⁺ level were higher in survivors than in non-survivors (94 ± 20 vs 79 ± 19 mm Hg and 140 ± 4 vs 136 ± 5 mmol/L, respectively; p < 0.001) and both remained higher during follow-up. There were no differences in baseline haemoglobin and serum K⁺ levels between these groups. Haemoglobin level decreased after 48 h of therapy only in patients who died (11.1 ± 2.4 vs 12.5 ± 2.1 g/dL; p < 0.01), whereas a reduction in serum K⁺ level after 48 h was observed only in survivors (4.2 ± 0.6 vs 3.9 ± 0.5 mmol/L; p < 0.05), probably reflecting effective diuretic therapy. Baseline renal function was more impared in non-survivors (serum creatinine 1.7 [1, 2.5] vs 1.2 [1, 1.6] mg/dL, and blood urea nitrogen 40 [24, 65] vs 24 [19, 33] mg/dL; p < 0.05) and deteriorated further during hospitalisation (serum creatinine 2.0 [1.2, 2.5] vs 1.2 [0.9, 1.5] mg/dL, blood urea nitrogen 64 [45, 77] vs 27 [19, 36] mg/dL; p < 0.01). Baseline plasma N-terminal proB-type natriuretic peptide (NT-proBNP) level did not differentiate these two groups, but plasma NT-proBNP level measured after 48 h was lower in survivors compared to non- -survivors (3560 [1711, 6738] vs 11780 [5371, 18912] pg/mL; p < 0.01); data are shown as medians [lower, upper quartile].
Conclusions: In our registry, in-hospital mortality in patients admitted due to acute HF was slightly higher compared to other reports. Baseline values of some parameters (e.g. blood pressure, serum Na⁺, renal function) as well as their changes during hospitalisation (e.g. serum K⁺, renal function, plasma NT-proBNP) can help identify acute HF patients at a higher risk of in-hospital mortality.
Kardiol Pol 2011; 69, 10: 997–1005