The Importance of Contrast Volume/Glomerular Filtration Rate Ratio in Contrast-Induced Nephropathy Patients after Transcatheter Aortic Valve Implantation

BACKGROUND/AIM: Transcatheter aortic valve implantation (TAVI) is a method which is increasingly applied in severe aortic stenosis treatment. The development of contrast-induced nephropathy (CIN) after TAVI increases morbidity and mortality rates. Within the scope of this study, the importance of the contrast medium volume to glomerular filtration rate (CV/GFR) ratio in determining the development of CIN and the amount of CV that could be applied was evaluated. METHODS: Seventy-two patients (aged 78.6 ± 11.6 years; 38 females) who underwent aortic valve replacement with the TAVI method between June 2013 and August 2014 were included in the study. CIN was defined as an absolute increase in serum creatinine of >0.5 mg/dl or a relative increase of >25% within 48-72 h after TAVI. CIN+ and CIN-patients were classified into two groups. The χ(2) test, t test, Mann-Whitney U test, ROC analysis, and univariate and multivariate regression analyses were applied for statistical analyses. RESULTS: CIN was detected in 16 patients (22%) in our study. Baseline creatinine, baseline GFR, the Mehran risk score, CV, and the CV/GFR ratio were determined as the predictive factors of CIN development. A CV/GFR ratio of 3.9 was specified to predict CIN development with 71% sensitivity and 80% specificity. CONCLUSION: After TAVI, CIN may develop due to various reasons. In patients to whom TAVI was applied, the CV/GFR ratio may be a guideline helping to prevent the development of renal pathologies. The amount of contrast medium that can be given to a patient can be calculated in terms of baseline GFR.