Introduction: The adverse prognosis in heart failure (HF) correlates with both NT-proBNP and high-sensitivity CRP levels. The latter indicates a greater underlying inflammatory process in more severe heart failure. This inflammatory response is also evidenced by elevated ferritin (acute phase reactant) and reduced haemoglobin (bone marrow suppression) amongst these patients. It is unclear if there is a linear relationship between NT-pro BNP with ferritin and haemoglobin levels.
Methods: We conducted a retrospective, cross-sectional study evaluating ferritin and haemoglobin values amongst patients with very high NT-proBNP levels (greater than 10,000 pg/ml).
Results: From October to December 2020, 150 patients were identified with very high NT-proBNP levels at a district hospital serving a local population of 500,000. 45 patients had a measured haemoglobin and ferritin level. We noted a direct correlation between NT-proBNP with ferritin and an indirect correlation between NT-proBNP and haemoglobin. With NTproBNP on the x-axis and haemoglobin on the y-axis, the trend line equated y = -0.0003x + 124.88. With NTproBNP on the x-axis and ferritin on the y-axis, the trend line equated y = 0.0043x + 311.6.
Conclusion: At very high NT-proBNP levels, haemoglobin levels decrease, and ferritin levels increase in a linear manner (small sample size did not allow for statistical significance). This is corroborated by data showing a direct relationship between high-sensitivity CRP and worsening heart failure. It is unclear if either ferritin or haemoglobin (or their temporal trend) can be utilised as a surrogate for measuring the underlying inflammatory process or in determining the prognosis in heart failure.