Patients with acute decompensation of heart failure and and low natriuretic peptide levels

Abstract

Abstract Funding Acknowledgements None. Background Nt-proBNP is frequently used in the diagnosis of acute decompensated heart failure (ADHF). However, there are some patients that although they have the clinical features of ADHF present with paradoxically low Nt-proBNP levels. Purpose To record the clinical and epidemiological characteristics of patients presenting with ADHF and low Nt-proBNP levels and compare them with those patients with high Nt-proBNP levels. Methods We retrospectively analyzed the data from the patients admitted with ADHF in our department, for a period of 2 years and divided them in 2 groups : low Nt-proBNP group (BNP<300 pg/ml) and high Nt-proBNP group (>300pg/ml). We recorded the clinical and epidemiological characteristics, the laboratory findings as well as the treatment they received. Results We recorded 636 patients admitted due to ADHF. 512 (80.5%) were in the high Nt-proBNP group and 124(19.5%) in the low Nt-proBNP group. Patients in the low Nt-proBNP group had more frequently BMI>25 (low Nt-proBNP vs high Nt-proBNP group) (65% vs 32%, p<0.01), and were more often females (71% vs 39%, p<0.05). In terms of heart failure classification, the low Nt-proBNP group had more often preserved ejection fraction (66% vs 42%, p<0.01) whereas in HFrEF (22% vs 39%) and HFmrEF (19% vs 12%) we did not notice any significant difference. Regarding age, less patients in the low Nt-proBNP group were older than 65 years old (62% vs 87%, p<0.05). The low Nt-proBNP group patients stayed longer in the hospital (9.2±2.4 days vs 6.6±3.7 days, p<0.01) needed smaller doses of furosemide (60±12,8 mg/d vs 180±24.2 mg/d, p<0.01) and more rare vasopressor (37% vs 42%) or inotropic (27% vs 56% , p<0.05) support. On the contrary, they needed more often non invasive ventilation (NIV) (73% vs 42%, p<0.05). As far as the laboratory findings is concerned, the low Nt-proBNP group presented with lower high sensitivity troponin I (hsTnI) levels (56±17.9 pg/ml vs 127±36.2 pg/ml, p<0.01) and higher GFR (96±12.2 mL/min/1.73 m² vs 45±23.7 mL/min/1.73 m², p<0.05). Conclusions Patients admitted with ADHF and low Nt-proBNP levels seem to be younger, females, with higher BMI and more often with preserved ejection fraction. It seems that they need more frequently non invasive ventilation , smaller doses of diuretics and require more days in the hospital. More studies are needed to identify the characteristics of this subset of patients that could lead to more effective management.