The influence of renal disease on outcomes and cardiac remodeling following surgical mitral valve replacement

Objectives: Chronic kidney disease (CKD) is increasingly prevalent in patients undergoing mitral valve replacement (MVR). While CKD is known to result in suboptimal outcomes for patients with mitral valve disease, there is limited literature evaluating the long-term outcomes and cardiac remodeling of patients with CKD undergoing MVR. We present the first analysis coupling long-term outcomes of combined morbidity, mortality, and cardiac remodeling post-MVR in patients with CKD.

Methods: Patients with varying degrees of CKD undergoing MVR from 2004 to 2018 were compared. Patients were grouped by estimated glomerular filtration rate (eGFR) > 90 mL/min/1.73m² (n = 109), 60-89 mL/min/1.73m² (450), 30-59 mL/min/1.73m² (449), < 30 mL/min/1.73m² (60). The primary outcome was mortality. Secondary outcomes included measures of postoperative morbidity and cardiac remodeling.

Results: One-year mortality was significantly increased in patients with eGFR < 30 (p = 0.023). Mortality at 7 years was significantly increased in patients with eGFR < 30 mL/min/1.73m² (p < 0.001). Multivariable regression analysis of 7-year all-cause mortality indicated an eGFR of 15 mL/min/1.73m² (HR 4.03, 95% CI 2.54-6.40) and 30 mL/min/1.73m² (HR 2.17 95% CI 1.55-3.05) were predictive of increased mortality. Reduced eGFR predicted the development of postoperative sepsis (p = 0.002), but not other morbidities. Positive cardiac remodeling of the left ventricle, left atrium, and valve gradients were identified postoperatively for patients with eGFR > 30 mL/min/1.73m² while patients with eGFR < 30 mL/min/1.73m² did not experience the same changes.

Conclusions: CKD is predictive of inferior clinical and echocardiographic outcomes in patients undergoing MVR and consequently requires careful preoperative consideration and planning. Further investigation into optimizing the postoperative outcomes of this patient population is necessary.