Associated factors for renal insufficiency in patients with heart failure with preserved ejection fraction

  Background  Heart failure with preserved ejection fraction (HFpEF) is considered as one of the most serious health threats in patients with cardiovascular disease. While suffering from HFpEF, up to 36.5% of patients may be complicated with renal insufficiency (RI), and their hospitalization rate, cardiovascular mortality and all-cause mortality increase significantly. Finding the associated factors of RI in HFpEF patients will be helpful to improving the quality of life and prolonging the lifespan of patients with HFpEF-RI comorbidity.

  Objective  To analyze the clinical parameters and echocardiographic parameters of patients admitting to the department of cardiology, so as to determine the risk factors of patients with HFpEF complicated with RI.

  Methods  From January 2010 to December 2020, a total of 3 682 patients with heart failure who were treated in the Department of Cardiology of the Second Medical Center of Chinese PLA General Hospital were selected, and 3 064 cases met the diagnostic criteria of HFpEF. The glomerular filtration rate (GFR) was calculated according to the epidemiological cooperative research formula of chronic kidney disease, and the HFpEF patients were divided into the following four groups according to the grading standard of the kidney disease prognosis quality guideline: group A with GFR≥90 mL/(min·1.73 m²) and renal function in grade 1 (n=1595), group B with 60≤GFR<90 mL/(min·1.73 m²) and renal function in grade 2 (n=1188), group C with 30≤GFR<60 mL/(min·1.73 m²) and renal function in grade 3 (n=214), group D with GFR<30 mL/(min·1.73m²) and renal function grade in 4 or 5 (n=67). The basic clinical characteristics, blood biochemical and echocardiographic parameters of the patients were recorded and compared among the groups. With GFR<60 mL/(min·1.73 m²) as the standard of RI, the related factors of RI were analyzed.

  Results  There were 3 064 patients with HFpEF, including 2 179 males and 885 females, with an average age of (61.41±15.00) years. With the decline of renal function, the differences in age, serum creatinine, cystatin, uric acid, homocysteine, N-terminal pro-brain natriuretic peptide, lipoprotein A, plasma fibrinogen, troponin, ventricular septal thickness and left ventricular posterior wall thickness between groups A, B, C, and D were statistically significant (all P<0.01), showing an overall upward trend. Meanwhile, the proportion of hypertension, diabetes and hyperlipidemia among the four groups also showed an increasing trend (all P<0.01). On the contrary, the proportion of male showed a decreasing trend (P<0.05). There were 9.17% of HFpEF patients combined with RI. Multivariate logistic regression analysis found that age, cystatin, homocysteine, and N-terminal pro-brain natriuretic peptide were independent risk factors for renal insufficiency in patients with HFpEF. ROC analysis found that for the prediction of renal insufficiency in HFpEF patients, the ROC-AUC (0.95%CI) for age, cystatin, homocysteine, N-terminal probrain natriuretic peptide and their combination was 0.716 (0.490-0.940), 0.791 (0.644-0.941), 0.690 (0.434- 0.931), 0.772 (0.538-0.983), 0.839 (0.697-0.989). Among them, cystatin and combined application (joint application Log P model) had high predictive efficiency.

  Conclusion  In HFpEF patients, aging, high homocysteine, high homocysteine and high N-terminal pro-brain natriuretic peptide are closely related to RI. Cystatin higher than 1.50 mg/L can be used as an early warning indicator of RI in patients with HFpEF.