Impact of Ascending Aorta Dilation on Mid-Term Outcome After Transcatheter Aortic Valve Implantation

Abstract: Background. Severe aortic stenosis (AS) is often associated with ascending aorta dilation (AAD). AAD is amenable to surgical correction combined with aortic valve replacement. Transcatheter aortic valve implantation (TAVI) might represent a valid therapeutic option in these patients when AAD correction Is not indicated. The aim of the present study is to evaluate the impact of concomitant AAD on early and mid-term outcomes after TAVI for symptomatic severe AS. Methods. This is a single-center observational study including patients undergoing transfemoral TAVI. All patients with previous surgery on the left ventricular outflow tract, aortic valve, or ascending aorta (except coronary artery bypass graft surgery) were excluded from the analysis. Patients undergoing TAVI for congenital aortic valve defects or subjects in whom a computed tomography (CT) scan was not available were excluded from the analysis. Ascending aortas were measured on CT scans using appropriate multiplanar reconstructions. Ascending aortas were qualified as dilated if the measurement was >40 mm. Study outcomes were death from any cause, significant paravalvular leaks (PVLs), and new permanent pacemaker (PPM) implant. Results. The final population consisted of 680 subjects, 61% females, mean age 82 ± 7 years. One hundred subjects (15%) had AAD. No differences in terms of significant PVL or PPM implantation were found between subjects with or without AAD (P>.99 and P=.13, respectively). At a median follow-up of 498 ± 216 days, no significant difference in terms of mortality was found between subjects with or without AAD (P=.78). Conclusions. AAD does not appear to impact the mid-term outcomes in a cohort of subjects undergoing TAVI.

J INVASIVE CARDIOL 2019;31(10):278-281. (Epub 2019 September 15).

Key words: aortic stenosis, transcatheter aortic valve implantation

Ascending aorta dilation (AAD) is commonly associated with severe aortic stenosis (AS). Current European and American practice guidelines recommend concomitant ascending aorta (AA) replacement in subjects undergoing surgical aortic valve replacement (SAVR) with an AAD >45 mm in diameter in order to prevent aortic dissection or rupture.^1,2 Currently, transcatheter aortic valve implantation (TAVI) is increasingly employed to correct severe AS, and its indication is expanding to intermediate surgical risk patients.³ Earlier reports have suggested that up to 1 in 4 patients undergoing TAVI have AAD.⁴ Aortic diameter appeared to influence procedural success in subjects undergoing TAVI with self-expandable devices, but not with balloon-expandable valves.^4,5 Mid-term survival did not appear to be influenced by AAD in subjects undergoing TAVI with balloon-expandable valves.⁴ In contrast with SAVR, patients undergoing TAVI with AAD cannot undergo AA replacement. Afterload reduction after TAVI could theoretically expose patients with AAD to a greater risk of postprocedural aortic rupture. The aim of the present work is to evaluate the impact of AAD on significant paravalvular leaks (PVLs), need for permanent pacemaker (PPM) implantation, and mid-term survival in a contemporary cohort of subjects undergoing TAVI with self-expandable or balloon-expandable devices.

Methods

Patients undergoing TAVI at our institution between January 2008 and June 2017 were included in the present analysis. All patients with previous surgery on the left ventricular outflow tract (LVOT), aortic valve, or AA (except coronary artery bypass grafting) were excluded from the analysis. We also excluded subjects undergoing TAVI for congenital aortic valve defects or subjects in whom a computed tomography (CT) scan was not available. AAs were measured on CT scans using appropriate double oblique multiplanar reconstructions using the OsiriX DICOM viewer (Pixmeo). AAD was defined as AA diameter >40 mm. Relevant outcomes were significant PVL and need for new PPM implantation during the index admission, and all-cause mortality on follow-up. Procedural success was defined according to Valve Academic Research Consortium-2 (VARC-2) criteria.^6,7 Baseline, procedural, and hospitalization data were recorded manually from institutional electronic medical records and entered into a dedicated anonymized database. The last clinical or telephone follow-up was recorded for each patient.

Statistical analysis. All continuous variables were tested for normality using the Shapiro-Wilk test and are expressed as mean ± standard deviation or median (interquartile range [IQR]), as appropriate. Between-group differences were tested using student’s t-test or Mann-Whitney test, as appropriate. Categorical variables are expressed as number (percentage of the total), and their association was tested using Chi-square test. Cumulative rates of death-free survival endpoints were calculated using the Kaplan-Meier method, and the log-rank test was used for comparisons across the groups. P-values <.05 were considered significant. Statistical analysis was performed with SPSS software, version 20.0 (SPSS).

Results

Patient population. During the study period, a total of 924 patients underwent TAVI at our institution. Two hundred forty-four patients did not fulfill inclusion criteria for the study (62 patients underwent non-transfemoral access, 69 patients underwent valve-in-valve or previous aortic interventions, 34 patients had bicuspid aortic valves, and 79 patients had incomplete imaging data). A total of 680 patients were therefore included in the present study. Mean age was 82 ± 7 years, and 61% were females. Balloon-expandable prostheses (Sapien, Sapien XT, Sapien 3 [Edwards Lifesciences]), self-expanding prosthesis (CoreValve and CoreValve Evolut R [Medtronic]; Portico [St. Jude Medical]), mechanical-expandable prostheses (Lotus [Boston Scientific]), and polymer-based frame prostheses (Direct Flow [Direct Flow Medical]) were included in the present analysis. Median AA diameter was 34 mm (IQR, 31-37 mm). One hundred patients (15% of the total) were found to have AAD; among them, 14 patients had an AA diameter of 45-50 mm and 3 patients had an AA diameter ≥50 mm. Table 1 summarizes clinical characteristics of the study patients. Those with AAD were more likely to be male (P<.01) and to have previously undergone percutaneous coronary intervention (P=.02). Figures 1A and 1B show two representative CT scans of subjects with and without AAD, respectively.

Mid-term outcomes after TAVI. Periprocedural death occurred in 2 patients (1 with AAD and 1 without AAD; P=.16). Vascular complications occurred in 96 patients (14%), with 13 (13%) in the AAD group and 83 (14%) in the non-AAD group (P=.72). Significant postprocedural PVL was detected in 74 patients (11%), with 11 (11%) in the AAD group and 63 (11%) in the non-AAD group, with no difference between groups (P>.99). Procedural success according to VARC-2 criteria was obtained in 605 patients (89% of the total population). No significant difference was observed in terms of procedural success between AAD and non-AAD patients (P=.62). New PPM implantation occurred in 78 patients (12%), with 16 (16%) in the AAD group and 62 (11%) in the non-AAD group, again with no difference between groups (P=.13). Mean follow-up was 498 ± 216 days. No differences were observed in overall mortality (14.8% in the AAD group vs 15% in the non-AAD group; P=.78) and cardiovascular mortality (8% in the AAD group vs 7% in the non-AAD group; P=.82) at 2-year clinical follow-up. Consistently, when balloon-expandable or self-expandable prostheses were separately analyzed, no differences for overall mortality (P=.83 and P=.74, respectively) or cardiovascular mortality (P=.66 and P=.69, respectively) were observed between the AAD and non-AAD groups. Figure 1C shows the Kaplan-Meier survival curves for the overall population, and Figures 1D and 1E show Kaplan-Meier survival curves for self-expandable and balloon-expandable prostheses, respectively.

Discussion

The main findings of this analysis are as follows: (1) in this series, the prevalence of AAD of patients with symptomatic severe AS undergoing TAVI was 15%, which is a slightly lower proportion than previously reported⁴ for TAVI patients; (2) no differences were observed in overall mortality (14.8% vs 15.0%; P=.78) and cardiovascular mortality (8% vs 7%; P=.82) in patients with and without AAD, respectively; and (3) no differences were confirmed for overall mortality or cardiovascular mortality according to valve type.

While histological evidence of aortic wall degeneration exists in AAD in the context of AS,⁸ the extent to which the risk of aortic dissection and aortic rupture affects the prognosis of these patients is currently unknown. Furthermore, earlier reports on subjects treated with self-expandable prostheses showed lower rates of successful device implantation in subjects with larger AAs.⁵ On the other hand, in our cohort, no impact was evident in terms of procedural success or mid-term survival between subjects with and without AAD.

Study limitations. Caution may be taken in the interpretation of these data, since the proportion of subjects presenting with moderate (ie, ≥45 mm) or severe (ie, ≥50 mm) AAD was extremely low. Further studies including a larger proportion of patients with moderate-to-severe AAD and with longer follow-up are therefore needed to assess the impact of AAD on the outcomes of TAVI patients.

Conclusion

AAD does not to appear to impact early and mid-term outcomes in a contemporary cohort of subjects undergoing TAVI.

References

1. Erbel R, Aboyans V, Boileau C, et al. 2014 ESC guidelines on the diagnosis and treatment of aortic diseases: document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European. Eur Heart J. 2014;35:2873-2926.

2. Hiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis and management of patients with thoracic aortic disease. J Am Coll Cardiol. 2010;55:e27-e129.

3. Baumgartner H, Falk V, Bax JJ, et al. 2017 ESC/EACTS guidelines for the management of valvular heart disease. Eur Heart J. 2017;38:2739-2791.

4. Rylski B, Szeto WY, Bavaria JE, et al. Transcatheter aortic valve implantation in patients with ascending aortic dilatation: safety of the procedure and mid-term follow-up^†. Eur J Cardiothorac Surg. 2014;46:228-233.

5. Maeno Y, Yoon S-H, Abramowitz Y, et al. Effect of ascending aortic dimension on acute procedural success following self-expanding transcatheter aortic valve replacement: a multicenter retrospective analysis. Int J Cardiol. 2017;244:100-105.

6. Ancona MB, Giannini F, Mangieri A, et al. Impact of mitral annular calcium on outcomes after transcatheter aortic valve implantation. Am J Cardiol. 2017;120:2233-2240.

7. Kappetein AP, Head SJ, Généreux P, et al. Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 Consensus Document. J Am Coll Cardiol. 2012;60:1438-1454.

8. Della Corte A, Quarto C, Bancone C, et al. Spatiotemporal patterns of smooth muscle cell changes in ascending aortic dilatation with bicuspid and tricuspid aortic valve stenosis: focus on cell-matrix signaling. J Thorac Cardiovasc Surg. 2008;135:8-18; 18.e1-18.e2.

*Joint first authors.

From the ¹Interventional Cardiology Unit, ²Radiology Unit, ³Heart Surgery Unit,  and ⁴Echocardiography Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Montorfano reports proctor income from Edwards Lifesciences, Boston Scientific, and St. Jude Medical. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript submitted April 20, 2019 and accepted May 1, 2019.

Address for correspondence: Marco B. Ancona, MD, Interventional Cardiology Unit, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy. Email: ancona.marco@hsr.it