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.

Radiation exposure during transcatheter aortic valve implantation (TAVI): comparison of balloon-expandable versus self-expandable prostheses

 

Transcatheter aortoc valve implantation (TAVI) is performed under fluoroscopic control and can be associated with the need for long fluoroscopy times and repeated cine acquisitions in angulated projections. The procedural steps for TAVI with balloon-expandable and self-expanding prostheses differ and may be associated with significant differences in radiation exposure. Published data regarding patient or operator radiation exposure in TAVI are limited to small series. We therefore analyzed the influence of prosthesis type on radiation exposure in a consecutive series of 1185 patients who underwent TAVI between 2016 and 2021.

A cohort of 1185 consecutive patients undergoing TAVI between 2016 and 2021 was analyzed. Radiation exposure was determined by evaluating overall fluoroscopy time, the number of acquired cine sequences, and total dose-area product (DAP). After eliminating patients treated via a non-transfemoral approach, data between patients underging TAVI with self-expanding prostheses and patients undergoing TAVI with balloon-expandable prostheses were compared.

Out of the total patient cohort, 46 patients were excluded due to treatment via a non-transfemoral approach. Of the remaining 1139 patients, 437 (38%) were treated with self-expandable prostheses and 702 (62%) were treated with balloon-expandable prostheses. Median age was 81 years, 45% of patients were female. Body weight was slightly but significantly higher in patients treated by balloon-expandable prostheses (median 73 kg vs. 79 kg, p<0.001). Median fluoroscopy time was 453 s (IQR 365–603 s) for self-expandable prostheses vs. 414 s (IQR 341–540 s) for balloon-expandable prostheses (p=0.002). Also, the number of cine acqusitions was significantly higher (median 12 vs. 7; p<0.001), and total DAP was 6442 mGy cm2 (IQR 4452–9669 mGy cm2) for self-expandable vs. 4798 (IQR 3353–6981 mGy cm2) for balloon-expandable prostheses (p<0.001, see Fig. 1). In multivariable analysis, male sex, higher body weight and use of a self-expandable prosthesis were independently associated with higher total DAP.

Transcatheter aortic valve implantation using balloon-expandable prostheses is associated with significantly lower total dose-area product than treatment with self-expandable prostheses. This may be particularly relevant for operators who perform the procedure frequently.

Funding Acknowledgement

Type of funding sources: None.

High-degree atrioventricular block after valve-in-valve transcatheter aortic valve implantation: incidence and predictors

Background

High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Data on the incidence of AV block for patients undergoing valve-in-valve (ViV) TAVI are scarce. We examined the incidence and predictors of periinterventional AV conduction disturbances in a cohort of subjects undergoing ViV TAVI compared to subjects undergoing TAVI of native aortic valves.

Methods

In 50 consecutive patients who underwent ViV TAVI, clinical characteristics, incidence and predictors for AV conduction disturbances as well as intrahospital outcome were assessed. Applying a matched pair approach for age, gender, type and size of transcatheter valve, these subjects were compared to 50 patients undergoing TAVI of native tricuspid aortic valves.

Results

Mean age in both groups was 80±6 years and 50% of subjects were male. In the ViV group, 22 patients (44%) had a stented bioprosthesis, 10 patients (20%) a stentless bioprosthesis and 18 patients (36%) a previous TAVI prosthesis (balloon-expandable: n=15, self-expandable n=3). The majority of subjects (92% in each group) were treated using balloon-expandable valves (ViV group: Sapien XT, n=20 or Sapien 3, n=26, control group: Sapien XT, n=19 or Sapien 3, n=27).

Periinterventional, non-reversible 3rd degree AV-block occurred in 6 patients within each group (12%), and all of the affected patients underwent PPM implantation. Among the 32 patients who underwent ViV-TAVI of a surgically placed bioprosthesis, only 2 (6%) developed a high-degree AV block (1/22 with a stented bioprosthesis and 1/10 with a stentless bioprosthesis). In contrast, high-degree AV block occurred in 4/18 patients (22%) who underwent ViV TAVI of a prior TAVI prosthesis. There was a significant difference in the occurrence of total high-degree AV blocks requiring postinterventional PPM implantation (p=0.033) between subjects who received TAVI of stented bioprostheses and those who received re-TAVI.

In logistic regression analysis, pre-existing RBBB represented a significant predictor for periinterventional 3rd degree AV block across the whole cohort (p=0.001, Exp(B)=10.667), both in ViV subjects (p=0.016, Exp(B)=12.0) and in the control group (p=0.018, Exp(B)=10.0).

Conclusion

Periinterventional AV block occurs infrequently in subjects undergoing ViV TAVI for treatment of degenerated surgical bioprostheses. However, patients undergoing ViV TAVI for degenerated transcatheter prostheses as well as subjects with pre-existing RBBB are at substantial risk for the occurence of AV block and require close peri-interventional monitoring.

Funding Acknowledgement

Type of funding sources: None.

The bad ventricle--revascularization versus transplantation

BACKGROUND

The proportion of patients with left-ventricular dysfunction (LVD) undergoing high risk revascularization is increasing. In this patient group, the perioperative risk is elevated because of the pre-existing pathophysiology. Detailed evaluation and interdisciplinary differential therapeutic considerations on the basis of the comparative benefit rationale, with cardiac transplantation alternative, is mandatory.

METHODS

Among 7275 patients who underwent coronary artery bypass grafting between 1990 and 1998 in our institution, we found 51 patients who had had an ejection fraction <20%, and thus were candidates for transplantation (group CABG); these were compared with 163 patients who were listed for cardiac transplantation because of ischemic cardiomyopathy (group HTX). The survival analysis was performed on the basis of the intention-to-treat principle independent of subsequent transplantation.

RESULTS

Both groups were comparable with regard to left-ventricular ejection fraction; pulmonary capillary wedge pressure and serum creatinine, but patients in the CAGB group were older (63+/-11 vs 56+/-8; p = 0.001) and included a higher percentage of women (m/f: 42/9 vs 152/11; p = 0.03). Nevertheless, there was a similar 1-year survival in both groups (group BP 71.9% vs group HTX 66.3%; p = ns). Looking at the CABG group, the internal thoracic artery was used in 36/51 patients, an intra-aortic balloon pump was used preoperatively in 26 patients, and intraoperatively in 6. Left-ventricular assist devices had to be inserted in three patients, extracorporeal membrane oxygenation once. Perioperative (30 day) survival was 88.2 %. An elevated preoperative serum creatinine and the nonusage of the internal thoracic artery predicted an adverse outcome. In the long-term course, the NYHA functional class improved in most cases from III preoperatively to I after 26 (2-66) months.

CONCLUSION

We conclude that patients with ischemic cardiomyopathy, viable myocardium, and graftable vessels can be revascularized with acceptable risk. Since for these patients a standby of mechanical circulatory support must be anticipated perioperatively, this infrastructure should be established within the center.