Can we predict postprocedural paravalvular leak after Edwards SAPIEN transcatheter aortic valve implantation?

A systematic review of contrast-enhanced computed tomography calcium scoring methodologies and impact of aortic valve calcium burden on TAVI clinical outcomes

Different methodologies have been used to assess the role of AV calcification (AVC) on TAVI outcomes. This systematic review aims to describe the burden of AVC, synthesize the different methods of calcium score quantification, and evaluate the impact of AVC on outcomes after TAVI. We included studies of TAVI patients who had reported AV calcium scoring by contrast-enhanced multidetector CT and the Agatston method. The impact of calcification on TAVI outcomes without restrictions on follow-up time or outcome type was evaluated. Results were reported descriptively, and a meta-analysis was conducted when feasible. Sixty-eight articles were included, with sample sizes ranging from 23 to 1425 patients. Contrast-enhanced calcium scoring was reported in 30 studies, calcium volume score in 28 studies, and unique scoring methods in two. All studies with calcium volume scores had variable protocols, but most utilized a modified Agatston method with variable attenuation threshold values of 300-850 HU. Eight studies used the Agatston method, with the overall mean AV calcium score in studies published from 2010 to 2012 of 3342.9 AU [95%CI: 3150.4; 3535.4, I2 ​= ​0%]. The overall mean score was lower and heterogenous in studies published from 2014 to 2020 (2658.9 AU [95% CI: 2517.3; 2800.5, I2 ​= ​79%]. Most studies reported a positive association between calcium burden and increased risk of adverse outcomes, including implantation of permanent pacemaker (7/8 studies), paravalvular leak (13/13 studies), and risk of aortic rupture (2/2 studies). AVC quantification methodology with contrast-enhanced CT is still variable. AVC negatively impacts TAVI outcomes independently of the quantification method.

Degree of valve calcification in patients undergoing transfemoral transcatheter aortic valve implantation with and without balloon aortic valvuloplasty: Findings from the multicenter EASE-IT TF registry

AIMS

We aimed to assess whether the level of aortic root calcification is associated with BAV performance/omission during transcatheter aortic valve implantation (TAVI), and to explore related outcomes.

METHODS AND RESULTS

EASE-IT TF was a prospective, observational, multicenter registry of patients undergoing TF-TAVI with the Edwards SAPIEN 3, with or without BAV predilation. Valvular calcification was quantified from pre-procedural multi-slice computed tomography images and compared between BAV and no BAV patients. Data for 178 patients (55 BAV; 123 no BAV) were analyzed. There were no significant differences between groups in terms of regional/leaflet sector calcification volumes, maximum asymmetry between the different leaflet sectors, or total calcification scores. Overall, a greater-than-average leaflet calcification volume was independently predictive of ≥mild PVL (OR: 5.116; 95% CI: 1.042-38.35) and the need for post-dilation (OR: 3.592; 95% CI: 1.173-12.14). The latter effect was abated in patients with BAV (OR: 1.837; 95% CI: 0.223-18.00) and intensified in those without BAV (OR: 5.575; 95% CI: 1.114-38.74). No other BAV-dependent effects of calcification on outcomes were observed.

CONCLUSIONS

In the majority of transfemoral valve implantations, calcification does not appear to be the main driving factor in the decision to perform/omit BAV. Predilation may be valuable for reducing post-dilation requirements in patients only with a greater degree of leaflet calcification.

CT support of cardiac structural interventions

Due to its high temporal and isotropic spatial resolution, CT has become firmly established for pre-procedural imaging in the context of structural heart disease interventions. CT allows to very exactly measure dimensions of the target structure, CT can provide information regarding the access route and, as a very valuable addition, volumetric CT data sets can be used to identify fluoroscopic projection angulations to optimally visualize the target structure and place devices. This review provides an overview of current methods and applications of pre-interventional CT to support adult cardiac interventions including transcatheter aortic valve implantation, percutaneous mitral valve intervention, left atrial appendage occlusion and paravalvular leak closure.

Clinical outcomes of the Lotus Valve in patients with bicuspid aortic valve stenosis: An analysis from the RESPOND study

AIMS

Patients with bicuspid valves represent a challenging anatomical subgroup for transcatheter aortic valve implantation (TAVI). This analysis evaluated the clinical outcomes of the fully repositionable and retrievable Lotus Valve System in patients with bicuspid aortic valves enrolled in the RESPOND post-market registry.

METHODS AND RESULTS

The prospective, open-label RESPOND study enrolled 1,014 patients at 41 centers in Europe, New Zealand, and Latin America, 31 (3.1%) of whom had bicuspid aortic valves. The mean age in the bicuspid patient cohort was 76.4 years, 64.5% were male, and the baseline STS score was 6.0 ± 10.2. Procedural success was 100%, with no cases of malpositioning, valve migration, embolization, or valve-in-valve. Repositioning was attempted in 10 cases (32.3%). There was one death (3.2%) and one stroke (3.2%) at 30-day follow-up. Mean AV gradient was reduced from 48.7 ± 17.0 mmHg at baseline to 11.8 ± 5.1 mmHg at hospital discharge (P < 0.001); mean effective orifice area (EOA) was increased from 0.6 ± 0.2 cm² to 1.7 ± 0.4 cm² (P < 0.001). There were no cases of moderate or severe paravalvular leak (PVL) adjudicated by the core laboratory; four subjects (13.8%) had mild PVL, 5 (17.2%) had trace PVL. The rate of pacemaker (PM) implantation for PM-naïve patients was 22.2% (6/27).

CONCLUSIONS

Data from the RESPOND registry demonstrate good clinical and echocardiographic outcomes up to 1 year postimplantation in patients with bicuspid aortic valves using the repositionable Lotus Valve.

Quantitative assessment of paravalvular leakage after transcatheter aortic valve replacement using a patient-specific pulsatile flow model

BACKGROUND

Quantitative assessment of post-transcatheter aortic valve replacement (TAVR) aortic regurgitation (AR) remains challenging. We developed patient-specific anatomical models with pulsatile flow circuit and investigated factors associated with AR after TAVR.

METHODS

Based on pre-procedural computed tomography (CT) data of the six patients who underwent transfemoral TAVR using a 23-mm SAPIEN XT, anatomically and mechanically equivalent aortic valve models were developed. Forward flow and heart rate of each patient in two days after TAVR were duplicated under mean aortic pressure of 80mmHg. Paravalvular leakage (PVL) volume in basal and additional conditions was measured for each model using an electromagnetic flow sensor. Incompletely apposed tract between the transcatheter and aortic valves was examined using a micro-CT.

RESULTS

PVL volume in each patient-specific model was consistent with each patient's PVL grade, and was affected by hemodynamic conditions. PVL and total regurgitation volume increased with the mean aortic pressure, whereas closing volume did not change. In contrast, closing volume increased proportionately with heart rate, but PVL did not change. The minimal cross-sectional gap had a positive correlation with the PVL volumes (r=0.89, P=0.02). The gap areas typically occurred in the vicinity of the bulky calcified nodules under the native commissure.

CONCLUSIONS

PVL volume, which could be affected by hemodynamic conditions, was significantly associated with the minimal cross-sectional gap area between the aortic annulus and the stent frame. These data may improve our understanding of the mechanism of the occurrence of post-TAVR PVL.

Transcatheter aortic valve implantation: where are we now?

Transcatheter aortic valve implantation (TAVI) was first used in clinical practice in 2002. Since 2002, there has been a rapid increase in TAVI activity in patients with symptomatic severe aortic stenosis. This has been supported by systematic randomized data comparing TAVI against the gold standard treatment for the last 50 years’ surgical aortic valve replacement. TAVI is now currently a recommended therapeutic intervention in the treatment of severe aortic stenosis patients who are deemed either high risk or inoperable. The indications for TAVI continue to expand. Within this review we will focus on the current guidelines for TAVI, the evidence for it, the complications of TAVI, postprocedure care, the technology available to clinicians now and finally the future perspectives for TAVI.

Predictors of Paravalvular Regurgitation After Implantation of the Fully Repositionable and Retrievable Lotus Transcatheter Aortic Valve (from the REPRISE II Trial Extended Cohort)

Paravalvular leak (PVL) after transcatheter aortic valve replacement is associated with worse long-term outcomes. The Lotus Valve incorporates an innovative Adaptive Seal designed to minimize PVL. This analysis evaluated the incidence and predictors of PVL after implantation of the Lotus transcatheter aortic valve. The REPRISE II (REpositionable Percutaneous Replacement of Stenotic Aortic Valve through Implantation of Lotus Valve System - Evaluation of Safety and Performance) Study With Extended Cohort enrolled 250 high-surgical risk patients with severe symptomatic aortic stenosis. Aortic regurgitation was assessed by echocardiography pre-procedure, at discharge and 30 days, by an independent core laboratory. Baseline and procedural predictors of mild or greater PVL at 30 days (or at discharge if 30-day data were not available) were determined using a multivariate regression model (n = 229). Of the 229 patients, 197 (86%) had no/trace PVL, 30 had mild, and 2 had moderate PVL; no patient had severe PVL. Significant predictors of mild/moderate PVL included device:annulus area ratio (odds ratio [OR] 0.87; 95% CI 0.83 to 0.92; p <0.001), left ventricular outflow tract calcium volume (OR 2.85; 95% CI 1.44 to 5.63; p = 0.003), and annulus area (OR 0.89; 95% CI 0.82 to 0.96; p = 0.002). When the device:annulus area ratio was <1, the rate of mild/moderate PVL was 53.1% (17 of 32). The rates of mild/moderate PVL with 0% to 5%, 5% to 10%, and >10% annular oversizing by area were 17.5% (11 of 63), 2.9% (2 of 70), and 3.2% (2 of 63), respectively. Significant independent predictors of PVL included device:annulus area ratio and left ventricular outflow tract calcium volume. When the prosthetic valve was oversized by ≥5%, the rate of mild or greater PVL was only 3%. In conclusion, the overall rates of PVL with the Lotus Valve are low and predominantly related to device/annulus areas and calcium; these findings have implications for optimal device sizing.

Assessment of Paravalvular Leak After Transcatheter Aortic Valve Replacement: Transesophageal Echocardiography Compared With Transthoracic Echocardiography

OBJECTIVES

Determine whether moderate or greater paravalvular leak (PVL) after transcatheter aortic valve replacement quantified using intraoperative transesophageal echocardiography (TEE) is associated with mortality and investigate the correlation between PVL grading using intraoperative TEE and postoperative transthoracic echocardiography (TTE).

DESIGN

Retrospective, observational study.

SETTING

Single academic institution.

PARTICIPANTS

The study comprised adult patients undergoing elective transcatheter aortic valve replacement between April 2011 and February 2014.

INTERVENTIONS

Patients were grouped by amount of PVL on intraoperative TEE into "significant" (moderate or greater) and "nonsignificant" (no, trivial, or mild) PVL groups. Demographics and patient characteristics were compared. Continuous variables were assessed with t-tests or Wilcoxon rank sum tests and categorical variables with the chi-square or Fisher exact test. A Cox proportional hazards model adjusted for EuroSCORE was used to test the independent association of PVL with late mortality, and covariate-adjusted survival curves were constructed. A Fleiss-Cohen-weighted kappa value was used to assess agreement between PVL grading using intraoperative TEE and postoperative TTE.

MEASUREMENTS AND MAIN RESULTS

One hundred ninety-six patients were grouped into the "significant" (n = 22) or "nonsignificant" (n = 174) PVL group. Twenty patients (10%) died during the follow-up period. Significant PVL on either TTE (p = 0.62, hazard ratio 1.68, 95% confidence interval [CI] 0.22-12.85) or TEE (p = 0.49, hazard ratio 0.49; 95% CI 0.06-3.68) was not associated with a survival difference. Modest agreement was found between PVL on intraoperative TEE and postoperative TTE (kappa = 0.47, CI 0.37-0.57, p < 0.0001).

CONCLUSIONS

Larger studies are needed to evaluate the association of PVL graded on intraoperative TEE with survival. There is modest agreement between the degree of PVL found on TEE and TTE.

Predilatation Prior to Transcatheter Aortic Valve Implantation: Is it Still a Prerequisite?

Predilatation has been historically considered a mandatory step before transcatheter aortic valve implantation (TAVI) since it facilitates valve crossing and prosthesis delivery, ensures optimal valve expansion and improves hemodynamic stability during valve deployment. However, as a result of procedural evolution over time, direct TAVI (without pre-implantation balloon aortic valvuloplasty) has emerged as an interesting option to simplify the procedure and to avoid potential valvuloplasty-related complications. Several real-world retrospective studies and one small randomised study have shown that direct TAVI (with both self-expanding and balloon-expandable prostheses) is feasible, safe and associated with outcomes similar to standard TAVI with pre-implantation balloon aortic valvuloplasty. In the absence of high-quality, robust evidence, the current review aims to discuss the advantages and disadvantages of omitting predilatation prior to TAVI.

Non-occlusive mesenteric ischemia accompanied by aortic regurgitation after transcatheter aortic valve implantation

An 81-year-old male with severe symptomatic aortic stenosis with ventricular tachycardia was referred for treatment. Balloon aortic valvuloplasty was performed under cardiopulmonary resuscitation. Though transcatheter aortic valve implantation (TAVI) was considered high risk for annulus rupture and aortic regurgitation due to annular calcification, TAVI was performed because of extremely high surgical risk. Moderate-to-severe aortic regurgitation (AR) remained and progression of acidosis could not be managed with continuous hemodiafiltration. His autopsy revealed the development of non-occlusive mesenteric ischemia (NOMI) as the cause of progressive acidosis. AR and hemodynamic instability might contribute to the development and progression of NOMI after TAVI.