Valve replacement surgery in severe chronic kidney disease.

BACKGROUND: The impact of prosthetic choices in patients with severe chronic kidney disease (CKD) on long-term outcomes has not been well established.

METHODS: The study involved 152 adult patients (61.6±14.1yrs.; 64 females) undergoing heart valve surgery who had stage 4 (n=87) or 5 CKD (end-stage; n=65) based on Kidney Disease Outcomes Quality Initiative Guidelines. To reduce the impact of selection bias between mechanical (n=92) and bio-prostheses groups (n=60), propensity score analyses were conducted.

RESULTS: Patients undergoing bioprosthetic replacement were significantly older and had poorer left ventricular function compared with those undergoing mechanical valve replacements. Early mortality rates were 10.0% in the Bio-prostheses group and 9.8% in the Mechanical group (P>0.99). During a median duration of 22.1months (Quartile 1-3, 4.7-68.1months; 87.5% complete), 56 patients died and 12 patients experienced valve-related complications. The unadjusted outcomes showed no significant differences in survival (P=0.23) and freedom from valve-related events (P=0.17). After adjustment, there was no significant difference in survival (Hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.62-1.71; P=0.91), however the bio-prostheses group showed significant superior outcomes of freedom from valve-related event (HR, 4.49; 95% CI, 1.04-19.45; P=0.045).

CONCLUSIONS: Valve replacement in CKD patients showed very high mortality risks and limited life expectancy even in younger individuals. When compared with bioprosthetic replacement, mechanical valve replacement showed similar survival rate but with greater risks of developing major valve-related complications in these patients. Therefore, bioprosthetic replacement may be a more reasonable option over mechanical replacement in these high-risk patients.