CT analysis of left ventricular function predicts short term survival in patients following transcatheter aortic valve implantation: 1-year outcome data

Introduction

Contrast-enhanced cardiac CT routinely performed prior to transcatheter aortic valve implantation (TAVI), allows assessment of cardiac morphology and function. We assessed left ventricular function in CT as a predictor of survival following TAVI.

Methods

500 consecutive patients referred for CT assessment of aortic root anatomy prior to TAVI were screened for inclusion in this analysis. All CT data sets were acquired using a third-generation dual source system. For assessment of aortic root anatomy, acquisitions were acquired using ECG-gated retrospective spiral acquisition and multiphase reconstructions in 10% increments of the cardiac cycle were rendered (slice thickness 0.75, increment 0.4 mm). left ventricular endocardial contours were automatically traced by a dedicated software (syngo. via, Siemens Healthineers, Forchheim, Germany) throughout the cardiac cycle and manually adjusted if required. Global left ventricular function parameters (end-diastolic and end-systolic volumes, stroke volume, cardiac output and ejection fraction) were derived by volumetric assessment.

Results

Out of 500 patients, 439 patients (mean age 80±6 years, 56% males, and Log EuroScore 23±14%) were included in this analysis (61 patients were excluded due to poor CT image quality or missing outcome data). Previous cardiac surgery had been performed in 15% of the patients, 50% had obstructive CAD with previous interventional or surgical revascularisation and 18% had a previous acute coronary syndrome. One-year survival was 83% (366/439 patients). Parameters of left ventricular function were as follows: mean LVEDV 172±56 ml, mean LVESV 78±62 ml, mean LV ejection fraction 59±18%, mean LV stroke volume index 51±22 ml/m2, mean LV cardiac output 6.6±3.3 L/min and LV cardiac index 3.5±1.7 l/min/m2. Cluster analysis of multiple LV-function surrogate parameters identified a group of patients with higher 1-year mortality, with LVEF identified as a predictor of 1-year survival with a cut-0ff of ≥37% associated with an OR 0f 0.52 (95% CI 0.27 to 0.98).

Conclusion

Assessment of left ventricular function using functional CT data sets is feasible and allows risk stratification of patients following TAVI. Among LV functional parameters, CT derived LV-ejection fraction with a cut-off ≥37% identifies patients with better short-term outcome.

Funding Acknowledgement

Type of funding sources: None.