Cardiorenal syndrome in patients with valvular heart disease

Abstract

Background: Few studies have examined cardiorenal syndrome in patients with significant valvular heart disease (VHD). Purpose: This study sought to evaluate the prevalence, factors associated with and the prognostic value of renal dysfunction and to determine whether surgery can affect the progression of renal dysfunction in patients with significant VHD. Methods: We evaluated 349 patients with significant VHD who were referred for valvular surgery. Patients were divided into those who underwent valvular surgery (n=286) and those who did not (n=63). Baseline renal function was assessed by estimated glomerular filtration rate (eGFR) and patients were consequently stratified as having stage 1, 2 or stage ≥3 chronic kidney disease (CKD). Mortality and change in eGFR were assessed after a median follow-up of 21 months. Results: The prevalence of CKD stage ≥3 was 25%. Impaired eGFR was associated with right atrial pressure (RAP) and pulmonary arterial systolic pressure (PASP). The presence of CKD stage ≥3 was associated with mortality, both in patients with and without surgery (Hazard ratio 4.39 and 9.34, P<0.01 and P=0.03, respectively). Importantly, patients with CKD stage ≥3 had a very high risk of mortality if surgery was not performed. Further, eGFR was preserved in patients who underwent valvular surgery but declined significantly in those who did not (68.4±16.7 to 62.1±19.6 mL/min/1.73m2, P<0.01). Conclusions: Renal dysfunction was common in patients with significant VHD and was associated with RAP and PASP. If left untreated surgically, these patients exhibited a rapid decline in renal function. Once renal dysfunction developed mortality became high.