Can Serum Cystatin C predict long-term survival in cardiac surgery patients?

Valentina Rovella,Nicola Toschi,Antonio Pellegrino,Maurizio Casasco,Michele Ferrannini,Mariarita Dessì,Nicola Di Daniele,Annalisa Noce,Giulia Marrone

doi:10.18632/aging.101403

Abstract

Renal dysfunction is a risk factor for morbidity and mortality in cardiac surgery patients. Serum Cystatin C (sCysC) is a well-recognized marker of early renal dysfunction but few reports evaluate its prognostic cardio-vascular role. The aim of the study is to consider the prognostic value of sCysC for cardiovascular mortality. Four hundred twenty-four cardiac-surgery patients (264 men and 160 women) were enrolled. At admission, all patients were tested for renal function and inflammatory status. Patients were subdivided in subgroups according to the values of the following variables: sCysC, serum Creatinine (sCrea), age, high sensitivity-C Reactive Protein, fibrinogen, surgical procedures and Kaplan-Meier cumulative survival curves were plotted. The primary end-point was cardiovascular mortality. In order to evaluate the simultaneous independent impact of all measured variables on survival we fitted a multivariate Cox-Proportional Hazard Model (CPHM). In Kaplan-Meier analysis 124 patients (29.4%) reached the end-point. In multivariate CPHM, the only significant predictors of mortality were sCysC (p<0.00001, risk ratio: 1.529, CI: 1.29-1.80) and age (p=0.039, risk ratio: 1.019, CI: 1.001-1.037). When replacing sCysC with sCrea, the only significant predictor of mortality was sCrea (p=0.0026; risk ratio 1.20; CI: 1.06-1.36). Increased levels of sCysC can be considered a useful biomarker of cardiovascular mortality in cardiac-surgery patients.

Highlights

End-stage renal disease requiring dialysis and severe renal disease represent a major risk factor in cardiacsurgery [1].there is another group of patients, showing no obvious clinical and laboratory signs of renal impairment, but who may have already an impaired renal function, such as patients older than 70 years
We divided the population studied in four subgroups, with respect to both the values of Serum Cystatin C (sCysC) and serum Creatinine (sCrea), since there is collinearity between these two filter markers
In our study we analyzed cardiac-surgery patients which during the surgical procedure are subjected to extracorporeal circulation which creates an inflammatory response with production of pro- and anti-inflammatory cytokines [12, 13]

Summary

Introduction

End-stage renal disease requiring dialysis and severe renal disease represent a major risk factor in cardiacsurgery [1]. There is another group of patients, showing no obvious clinical and laboratory signs of renal impairment, but who may have already an impaired renal function, such as patients older than 70 years. These patients, representing a significant proportion of www.aging‐us.com those requiring cardiac surgery, have a higher risk of worsening renal function degenerating into a dialysisdependent renal failure [2]. SCrea levels may be influenced by several factors, such as sex, age, race, metabolism, drugs, protein intake [3, 4] and may be inaccurate in several situations, such as in patients with low muscle mass or with fluid overload [5]

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