Risk factors and short-term prognosis of preoperative renal insufficiency in infective endocarditis

The incidence of postoperative complications and the in-hospital mortality rate of infective endocarditis (IE) complicated with renal insufficiency are relatively high. This study aimed to analyze the clinical features, etiological characteristics, diagnosis and treatment, and prognosis of IE with renal insufficiency and to explore the risk factors for renal damage.

IE patients undergoing valvular surgery between 2008 and 2017 in two cardiac centers were retrospectively analyzed. They were divided into renal insufficiency (RI) [endogenous creatinine clearance rate (Ccr) <60 mL/min/1.73 m²] and normal renal function (NRF) (Ccr ≥60 mL/min/1.73 m²) groups. The disease conditions at admission, etiology, treatment, and prognosis were compared between the two groups. Multivariate regression analysis was performed for the related factors.

A total of 8,055 cases of valvular surgery was performed during the study period. We analyzed 401 IE patients [average age 43.9±15 years; RI, n=56 (14%); NRF, n=345 (86%)], after the exclusion of 2 patients with primary glomerulonephritis. RI patients showed higher perioperative mortality (14.3% vs. 4.5%, P=0.042) and streptococcal infection (71.4% vs. 43.8%, P=0.001) rates. The RI group was also older and had worse heart function, greater decreases in hemoglobin and platelet levels, a higher rate of prosthetic valve involvement, more cases of postoperative dialysis, and worse prognosis (all P<0.05). Binary logistic multivariate regression analysis showed that the incidence of streptococcal infection [odds ratio (OR) =4.271, 95% confidence interval (CI), 1.846-9.884; P=0.001], age ≥51 years (OR =5.138, 95% CI, 2.258-11.694; P<0.001), and New York Heart Association (NYHA) functional class III-IV (OR =10.768, 95% CI, 2.417-47.972; P=0.002) were independent risk factors for preoperative renal insufficiency.

IE patients with preoperative renal insufficiency had a high mortality rate and poor prognosis, with streptococcal infection predisposing to a higher risk of renal insufficiency. Moreover, older the age and worse heart function in IE resulted in a greater risk for renal insufficiency.