Value of microalbuminuria in the diagnosis of heart failure with preserved ejection fraction.

Objective: Elevated microalbuminuria (MAU) levels have been demonstrated in patients with heart failure with reduced ejection fraction (HFrEF). However, nothing is known about MAU levels in patients with heart failure with preserved ejection fraction (HFpEF). Therefore, the aim of our study was to explore the relationship between MAU levels and HFpEF.

Methods: The MAU and N‑terminal B‑type natriuretic peptide (NT-proBNP) concentrations were examined in 260 participants, including 160 patients with HFpEF and 100 control subjects without HF. Echocardiography was performed on all study participants. The patients with HFpEF were divided into class II, III, or IV according to the New York Heart Association (NYHA) classification.

Results: The MAU levels in the HFpEF group were significantly higher than those in the non-HF group (58.97 ± 89.84 vs. 19.56 ± 29.34, p > 0.05). However, there was no significant difference in the levels of MAU among NYHA class II-IV patients in the HFpEF group (p > 0.05). In Pearson linear correlation analysis, MAU levels in the HFpEF group were positively correlated with left atrial diameter (LAD; r = 0.344, p < 0.05), but negatively correlated with hemoglobin (r = - 0.233, p < 0.05). The area under the ROC curve (AUC) of MAU for the diagnosis of HFpEF was 0.83 (95% CI [0.76, 0.90], p < 0.05), the sensitivity was 72.50%, and the specificity was 82.0%. The AUC of NT-proBNP was 0.88 (95% CI [0.83, 0.94], p < 0.05), the sensitivity was 82%, and the specificity was 73.8%. The AUC of MAU combined with NT-proBNP was 0.91 (95% CI [0.86, 0.96], p < 0.05).

Conclusion: Our results show that MAU can be used as a biomarker for the diagnosis of HFpEF. Combined detection of MAU with NT-proBNP has clinical value in improving the accuracy of diagnosis of HFpEF. However, there is no significant correlation between MAU levels and the severity of HFpEF.