European Studies Assess Factors Related to TAVI

December 27, 2009—Rodrigo Bagur, MD, et al published a study that sought to determine the incidence, predictive factors, and prognostic value of acute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI) and to compare the occurrence of AKI in TAVI versus surgical aortic valve replacement (SAVR) in patients with preprocedural chronic kidney disease (CKD). The investigators conducted the study because little data exist on the occurrence of AKI associated with TAVI. The study was published online ahead of print in the European Heart Journal.

As detailed in the European Heart Journal, 213 patients (mean age, 82 ± 8 years) undergoing TAVI to treat severe aortic stenosis were included in the study. AKI was defined as a reduction of > 25% in estimated glomerular filtration rate (eGFR) within 48 hours after the procedure or the need for hemodialysis during index hospitalization. Patients with preprocedural CKD (eGFR < 60 mL/min/1.73 m2; n = 119) were compared with 104 contemporary patients with CKD who underwent isolated SAVR. The incidence of AKI after TAVI was 11.7%, with 1.4% of the patients requiring hemodialysis. Predictive factors of AKI were hypertension (odds ratio [OR], 4.66; 95% confidence interval [CI], 1.04–20.87), chronic obstructive pulmonary disease (OR, 2.64; 95% CI, 1.1–6.36), and perioperative blood transfusion (OR, 3.47; 95% CI, 1.3–9.29).

The investigators reported that 21 patients (9.8%) died during index hospitalization, and the logistic EuroSCORE (OR, 1.03 for each increase of 1%; 95% CI, 1.01–1.06) and occurrence of AKI (OR, 4.14; 95% CI, 1.42–12.13) were identified as independent predictors of postoperative mortality. Patients with CKD who underwent TAVI were older, had a higher logistic EuroSCORE, and had lower preprocedural eGFR values compared with those who underwent SAVR (P < .0001 for all). The incidence of AKI was lower (P = .001; P = .014 after propensity score adjustment) in CKD patients who underwent TAVI (9.2%; need for hemodialysis, 2.5%) compared with those who underwent SAVR (25.9%; need for hemodialysis, 8.7%).

The findings demonstrated that acute kidney injury occurred in 11.7% of the patients after TAVI and was associated with a greater than fourfold increase in the risk of postoperative mortality. Hypertension, chronic obstructive pulmonary disease, and blood transfusion were predictive factors of AKI. In patients with preprocedural CKD, TAVI was associated with a significant reduction of AKI compared with SAVR, the investigators concluded.

Also online ahead of print in the European Heart Journal, Lutz Buellesfeld, MD, et al published an analysis that sought to identify predictors of procedural success in percutaneous TAVI. The investigators prospectively assessed in-hospital outcomes of patients undergoing TAVI at two institutions, the Helios Heart Center in Siegburg, Germany, and Bern University Hospital in Bern, Switzerland. They analyzed clinical, morphological, and procedural parameters using univariate and multivariate regression models. Between 2005 and 2008, a total of 168 consecutive patients with symptomatic aortic valve stenosis underwent TAVI using the self-expanding CoreValve Revalving prosthesis (CoreValve, Inc., Irvine, CA; acquired in 2009 by Medtronic, Inc., Minneapolis, MN).

As detailed in the European Heart Journal, 93% of the patients were highly symptomatic, with a New York Heart Association grade of III/IV and a mean aortic valve area of 0.66 ± 0.21 cm². Acute and in-hospital procedural success rates were 90.5% and 83.9%, respectively, with in-hospital mortality, myocardial infarction, and stroke rates of 11.9%, 1.8%, and 3.6%, respectively. Predictors of in-hospital procedural success were the type of access (OR, 0.33; 95% CI, 0.13–0.82; P = .017), previous coronary intervention (OR, 5.3; 95% CI, 1.2–23.41; P = .028), and preprocedural Karnofsky index using univariate regression, which emerged as the only independent predictor (OR, 1.04; 95% CI, 1–1.08; P = .032) in the multivariate analysis.

The investigators concluded that preprocedural functional performance status predicts the in-hospital outcome after TAVI. Patients with a good functional status are likely to benefit more from TAVI than previously reported high-risk patients.