Tools and Techniques - Clinical: Fluoroscopic balloon sizing of the aortic annulus before transcatheter aortic valve replacement (TAVR) - follow the "right cusp rule"

Evaluation of a Low-Dose Radiation Protocol During Transcatheter Aortic Valve Implantation

We aimed to evaluate the efficacy and safety of a low-dose imaging protocol to reduce intraprocedural radiation during transcatheter aortic valve implantation (TAVI). Observational analysis: 802 transfemoral TAVI patients receiving balloon-expandable devices ≥23 mm at a high-volume centre. After propensity score matching, a standard-dose group (SD, n = 333) treated between January 2014 and February 2016 was compared with a low-dose group (LD, n = 333) treated between August 2017 and March 2019 after departmental uptake of a low-dose imaging protocol (reduced field size, high table height, use of "fluoro save," 3.75 frames/second acquisition, increased filtering). Primary end point was dose-area product (DAP). Secondary safety end points were VARC-2 device success and a composite of in-hospital complications. The LD protocol was associated with lower DAP (4.64 [2.93, 8.42] vs 22.73 [12.31, 34.58] Gy⋅cm², p <0.001) and fluoroscopy time (10.4 [8.1, 13.9] vs 11.5 [9.1, 15.3] minutes, p = 0.001). Contrast use was higher in the LD group (LD 110 [94, 130] vs SD 100 [80, 135] milliliters, p = 0.042). Device success (LD 88.3% vs SD 91.3%, p = 0.25), and the composite end point (LD 8.1% vs SD 11.4%, p = 0.19) were similar. In multivariate analysis, the low-dose protocol was associated with a 19.8 Gy⋅cm² reduction in procedural DAP (p <0.001). In conclusion, compared with standard imaging, a low-dose protocol for TAVI significantly reduced radiation dose without compromising outcomes.

Asymptomatic severe aortic stenosis, bicuspid aortic valves and moderate aortic stenosis in heart failure: New indications for transcatheter aortic valve implantation

Aortic stenosis (AS) remains one of the most common valvular heart diseases, with enormous impact on patient survival. Over the past years, transcatheter aortic valve implantation (TAVI) has become a reality worldwide, offering a less invasive method to treat AS. Apart from the classical indications for aortic valve disease, recent studies tried to address unanswered questions for TAVI - asymptomatic severe AS, bicuspid aortic valves and moderate AS in patients with heart failure. This review discusses the rationale of those possible indications, pitfalls and current evidence in the medical literature.

Novel predictors of mild paravalvular aortic regurgitation in SAPIEN 3 transcatheter aortic valve implantation

AIMS

Paravalvular leak (PVL) remains an important issue in TAVI. The Edwards SAPIEN 3 (S3) valve has reduced PVL but in up to one third of patients mild leak remains. Our study aimed to identify predictors of mild PVL after TAVI with the S3 valve.

METHODS AND RESULTS

From October 2015 to May 2017, 122 consecutive patients underwent S3 TAVI for symptomatic severe aortic stenosis. Thirty-three patients with mild PVL on transthoracic echocardiography at 30-day follow-up were compared to 89 with none/trace PVL. Thirty-day mortality was 2.5% (n=3), with zero stroke and major vascular complications. There were no differences between the two groups in patient characteristics, annular and left ventricular outflow tract (LVOT) sizing, distribution and severity of annular calcification, valve implantation technique, post-dilatation and implant depth. Mild PVL was associated with higher annular eccentricity (p=0.04) and moderate-severe LVOT calcification (p=0.03). Independent predictors of mild PVL were LVOT eccentricity (OR 1.05 per % ellipticity, 95% CI: 1.02-1.09, p=0.005), discordant sizing (OR 3.08, 95% CI: 1.20-7.90, p=0.02) and three-leaflet calcification (OR 13.3, 95% CI: 2.66-66.7, p=0.002).

CONCLUSIONS

LVOT eccentricity and discordant sizing predict PVL after S3 TAVI. Further studies are needed to understand their mechanism and significance.

Transcatheter Treatment of Bicuspid Aortic Valve Disease: Imaging and Interventional Considerations

Patients with bicuspid aortic valve disease have systematically been excluded from large randomized clinical trials investigating transcatheter aortic valve implantation (TAVI) due to their younger age, lower surgical risk and complex aortic anatomy. The asymmetric nature of the bicuspid valve orifice often accompanied by heavy regional calcification has led to concerns regarding valve positioning and expansion. Bicuspid aortic valve disease patients are at heightened risk of TAVI-related complications including coronary occlusion, aortic dissection and annular rupture, as well as the known risks of progressive aortopathy in these patients. These unique anatomical characteristics pose challenges for TAVI operators. However, with recent and ongoing refinements in implantation technique, improvements in pre-procedural imaging and iterations in device design, TAVI is emerging as a safe and feasible treatment option in this population. Paravalvular aortic regurgitation and high pacemaker rates have been the Achilles Heel for TAVI in bicuspid valve patients, yet newer generation devices are yielding promising results. Further studies are required before TAVI ultimately emerges as a viable option in low and intermediate surgical-risk patients with bicuspid valve disease. This review comprehensively summarizes the epidemiology, pathology and current evidence for TAVI in patients with bicuspid aortic valve disease. We also outline some practical tips for performing TAVI in these patients.

Supra-annular structure assessment for self-expanding transcatheter heart valve size selection in patients with bicuspid aortic valve

Objectives

To explore assessment of supra‐annular structure for self‐expanding transcatheter heart valve (THV) size selection in patients with bicuspid aortic stenosis (AS).

Background

Annulus‐based device selection from CT measurement is the standard sizing strategy for tricuspid aortic valve before transcatheter aortic valve replacement (TAVR). Because of supra‐annular deformity, device selection for bicuspid AS has not been systemically studied.

Methods

Twelve patients with bicuspid AS who underwent TAVR with self‐expanding THVs were included in this study. To assess supra‐annular structure, sequential balloon aortic valvuloplasty was performed in every 2 mm increments until waist sign occurred with less than mild regurgitation. Procedural results and 30 day follow‐up outcomes were analyzed.

Results

Seven patients (58.3%) with 18 mm; three patients (25%) with sequential 18 mm, 20 mm; and only two patients (16.7%) with sequential 18 mm, 20 mm, and 22 mm balloon sizing were performed, respectively. According to the results of supra‐annular assessment, a smaller device size (91.7%) was selected in all but one patient compared with annulus based sizing strategy, and the outcomes were satisfactory with 100% procedural success. No mortality and 1 minor stroke were observed at 30 d follow‐up. The percentage of NYHA III/IV decreased from 83.3% (9/12) to 16.7% (2/12). No new permanent pacemaker implantation and no moderate or severe paravalvular leakage were found.

Conclusions

A supra‐annular structure based sizing strategy is feasible for TAVR in patients with bicuspid AS.

Left Ventricular Outflow Tract Migration of a Balloon-Expandable Prosthesis During Transcatheter Aortic Valve Implantation

Valve migration into the left ventricular outflow tract (LVOT) during transcatheter aortic valve implantation (TAVI) is a life-threatening complication. An 89-year-old female patient was admitted for TAVI due to severe symptomatic aortic stenosis. After deployment of a balloon-expandable prosthesis, the prosthesis had migrated into the LVOT. The prosthesis was reimpacted to the aortic annulus by a balloon-assisted recapture procedure. Immediately after recapturing the prosthesis with an oversized balloon, the patient's vital signs deteriorated due to acute aortic regurgitation (AR), and a prompt valve-in-valve (V-in-V) procedure allowed us to stabilize the patient's condition. This is the first reported case of a V-in-V procedure using an oversized balloon and a larger prosthesis to treat migration of the initial prosthesis into the LVOT. Balloon recapture and V-in-V procedure using an oversized balloon and larger prosthesis for a migrated balloonexpandable prosthesis into the LVOT is feasible, but hemodynamic support should be prepared before recapture and Vin-V because overdilatation of the first prosthesis might cause hemodynamic collapse due to severe AR.