Risk factors for acute kidney injury following TA-TAVI or minimally invasive aortic valve replacement: which procedure is less kidney damaging in elderly patients?

BACKGROUND: Acute kidney injury (AKI) represents a major complication following aortic valve replacement in elderly patients. The aim of this study was to determine possible risk factors for AKI and to find the ideal strategy, minimally invasive valve replacement (MIS-AVR) or transapical valve implantation (TA-TAVI), regarding the postoperative renal outcome.

METHODS: A total of 133 patients (age ≥ 75 years, 67 male) with severe aortic stenosis were included over 2 years: 42% were treated with MIS-AVR, 58% underwent TA-TAVI procedure. AKI was considered as a postprocedural 1.5× increase in creatinine or an increase of > 0.3 mg/dL/48 hours. Group differences were tested with chi-square or t-test. AKI risk assumption was analyzed in multiple multivariate logistic regression models.

RESULTS: EuroSCORE II-related risk assumption was 8.7 ± 6.9 for TA-TAVI and 4.5 ± 5.7 for MIS-AVR (p < 0.001). The overall 30-day survival rate was 93%. Fifty-eight patients developed a risk for AKI and 13 developed a manifest renal injury/failure. Logistic regression analysis revealed a higher AKI risk for TA-TAVI (odds ratio, OR = 2.58; 95% confidence interval, CI = 1.18, 5.63; p = 0.017). EuroSCORE II (OR = 0.98; 95% CI = 0.92, 1.04; p = 0.433); preoperative creatinine (OR = 1.78; 95% CI = 0.67, 4.77; p = 0.249) and estimated glomerular filtration rate (OR = 1.00; 95% CI = 0.97, 1.02; p = 0.655) had no impact on AKI. A regression model adjusting for the variables age, gender, body mass index (BMI), diabetes, and procedure type revealed a higher AKI rate for male gender (OR = 2.41; 95% CI = 1.13, 5.11; p =  0.022). Operation time and radio-contrast media volume had no influence on the AKI-occurrence. There was no correlation between AKI and early mortality.

CONCLUSION: A higher risk for AKI after TA-TAVI should be considered in the therapy decision, especially in elderly male patients because MIS-AVR still yields excellent results.