Predicting Device Success and Early Clinical Outcome after Transapical Aortic Valve Implantation

Abstract

Objective: Pre-procedural evaluation of aortic valve patients is based on the prediction of perioperative risk for a conventional aortic valve replacement (AVR) utilizing standardized risk scores. However, in in the era of transcatheter aortic valve implantation (TAVI) the specific prediction of procedural outcome of an interventional approach seems of growing importance. We aimed to isolate patient- and approach-related factors, predicting procedural outcome of transapical aortic valve implantation (TA-TAVI), especially focusing on parameters not included in standard risk scores (e.g. BMI, intracardiac anatomy, preoperative NT-proBNP). Methods: A cohort of 60 patients suffering from severe aortic stenosis and receiving TA-TAVI at our institution was analyzed (mean age was 77.7 ± 6.3 years, 50% male). All patients exhibited a high risk for conventional AVR (EuroScorelog ≥ 20 or porcelain aorta) and were scheduled for a TA approach using an Edwards Sapien valve following heart-team discussion. Prior the procedure, all patients underwent multi-slice computed tomography examination. In order to evaluate the procedural and clinical outcome after TA-TAVI, three endpoints were defined: More than mild postoperative paravalvular leak (PVL), postoperative mean transvalvular gradient > 14 mmHg and a composite endpoint of 30-day mortality, stroke and myocardial infarction. For isolation of outcome predictors, fourteen different potential predictors were included into primary univariate regression analyses, seven of which entered subsequent multivariate analyses. Results: A BMI ≥ 30 was found in multivariate logistic regression to double the risk for both more than mild PVL and higher postoperative transvalvular gradients, however without reaching statistical significance (OR 2.57 95% CI 0.69-9.52; p=0.157 and OR 2.32 95% CI 0.57-9.45; p=0.242, respectively). Male gender and COPD were both associated with a decreased risk for elevated postoperative gradients. Of the analyzed approach-related parameters, especially a LVOT-aorta angle <120° was associated with an increased risk of the composite end-point (OR 6.65 95% CI 0.93-47.4; p=0.059). Furthermore preoperative NT-proBNP levels <400 ng/ml were found to predict a trend towards higher postoperative transvalvular gradients (OR 5.15 95% CI 0.32-81.9; p=0.246). Conclusion: Standardized risk scores for conventional AVR are limited in terms of predicting the early outcome of TAVI procedures. The current study provides evidence that specific parameters such as the LVOT-aorta angle are likely to improve outcome prediction of patients undergoing TAVI procedures.