LAUSR

Uremic toxins negatively affect the cardiovascular system resulting in significant morbidity and mortality. However, independent risk factors for chronic kidney disease (CKD) and that of worsening CKD have not been studied in patients with tricuspid regurgitation (TR), yet. Accordingly, in this study, we aimed to assess independent risk factors for the development of progressive CKD in patients with TR. Also, the impact of progressive CKD on long-term mortality was evaluated. This retrospective, single-center study comprised 444 consecutive patients with TR who were hospitalized between January 2010 and June 2017. We excluded patients with CKD stage 5. Demographic data, comorbidities, type of admission, medication, echocardiographic and laboratory parameters, and survival status were obtained from patient medical record from index hospital admission through discharge. For at least three years, serum creatinine concentrations and survival status were collected from outpatient medical record. We identified independent risk factors for CKD progression. Also, we assessed the impact of CKD progression and other variables on 3-year mortality using multivariable logistic regression analysis. For analysis of 3-year mortality, we grouped patients according to different combinations of their TR grade and presence or absence of CKD progression. Stage of CKD at hospital admission (odds ratio 0.34 [95% confidence interval 0.24-0.50], p < 0.001), baseline hemoglobin concentration (OR 0.72 [95% CI 0.57-0.92], p=0.006) and presence of diabetes type 2 (OR 1.81 [95% CI 1.08-3.03], p=0.024) were identified as independent risk factors for CKD progression. Progression of CKD during follow-up (OR 2.16 [95% CI 1.31-3.57], p=0.003), grade of TR and mitral regurgitation during index hospital stay and hemoglobin concentration at baseline were independent risk factors for 3-year mortality. Combination of TR grade and status of CKD progression showed a stepwise pattern for 3-year mortality (Figure 1). Patients with TR 1 and CKD progression had a similar 3-year mortality as patients with TR 2 or 3 but no CKD progression. In patients with TR 1, risk for 3-year mortality doubled if CKD progression occurred (OR 2.49 [95% CI 1.38-4.47], p=0.002). Although retrospective studies cannot imply causal relationship, based on study findings, kidney follow-up especially in patients with mild TR may be advisable. If CKD progression can be prevented in patients with TR and if such kidney protection may reduce long-term mortality may be objective of future studies.