Surgical Explantation of Transcatheter Aortic Bioprostheses: Balloon vs Self-Expandable Devices

Transcatheter Aortic Valve Replacement is Ready for Most Low-risk Patients: A Systematic Review of the Literature

Transcatheter aortic valve replacement (TAVR) has undergone rapid expansion, emerging as a viable therapeutic option for low-risk patients in lieu of surgical aortic valve replacement. This paper aims to provide a review of the scientific evidence concerning TAVR in low-risk patients, encompassing both observational and clinical trial data. Furthermore, a substantial proportion of low-risk patients possesses a bicuspid aortic valve, necessitating careful examination of the pertinent anatomic and clinical considerations to TAVR that is highlighted in this review. Additionally, the review expands upon some of the unique challenges associated with alternate access in low-risk patients evaluated for TAVR. Last, this review outlines the pivotal role of a multidisciplinary heart team approach in the execution of all TAVR procedures and the authors' vision of 'minimalist TAVR' as a new era in low-risk TAVR.

Lifetime Management for Aortic Stenosis: Strategy and Decision-Making in the Current Era

Aortic stenosis, the most common valvular disease in the Western world, has traditionally been treated with surgical aortic valve replacement (SAVR) but is increasingly treated by transcatheter aortic valve replacement (TAVR). Whereas patients older than 65 years are preferably treated with bioprosthetic tissue valves, there is considerable uncertainty in the choice between TAVR and SAVR. We present various considerations for optimizing the lifelong management of patients receiving bioprosthetic valves (SAVR or TAVR). To maximize life expectancy and to minimize cumulative lifetime risk, we suggest decision-making individualized for patient anatomy and overall (current and future) risk.

Transcatheter heart valve explant with infective endocarditis-associated prosthesis failure and outcomes: the EXPLANT-TAVR international registry

BACKGROUND AND AIMS

Surgical explantation of transcatheter heart valves (THVs) is rapidly increasing, but there are limited data on patients with THV-associated infective endocarditis (IE). This study aims to assess the outcomes of patients undergoing THV explant for IE.

METHODS

All patients who underwent THV explant between 2011 and 2022 from 44 sites in the EXPLANT-TAVR registry were identified. Patients with IE as the reason for THV explant were compared to those with other mechanisms of bioprosthetic valve dysfunction (BVD).

RESULTS

A total of 372 patients from the EXPLANT-TAVR registry were included. Among them, 184 (49.5%) patients underwent THV explant due to IE and 188 (50.5%) patients due to BVD. At the index transcatheter aortic valve replacement, patients undergoing THV explant for IE were older (74.3 ± 8.6 vs. 71 ± 10.6 years) and had a lower Society of Thoracic Surgeons risk score [2.6% (1.8-5.0) vs. 3.3% (2.1-5.6), P = .029] compared to patients with BVD. Compared to BVD, IE patients had longer intensive care unit and hospital stays (P < .05) and higher stroke rates at 30 days (8.6% vs. 2.9%, P = .032) and 1 year (16.2% vs. 5.2%, P = .010). Adjusted in-hospital, 30-day, and 1-year mortality was 12.1%, 16.1%, and 33.8%, respectively, for the entire cohort, with no significant differences between groups. Although mortality was numerically higher in IE patients 3 years postsurgery (29.6% for BVD vs. 43.9% for IE), Kaplan-Meier analysis showed no significant differences between groups (P = .16).

CONCLUSIONS

In the EXPLANT-TAVR registry, patients undergoing THV explant for IE had higher 30-day and 1-year stroke rates and longer intensive care unit and hospital stays. Moreover, patients undergoing THV explant for IE had a higher 3-year mortality rate, which did not reach statistical significance given the relatively small sample size of this unique cohort and the reduced number of events.

Valve Type and Operative Risks in Surgical Explantation of Transcatheter Aortic Valves: A Systematic Review and Meta-Analysis

Indication to perform surgical explantation of TAVR is becoming increasingly more frequent, due to the higher number of transcatheter procedures performed in patients with longer life expectancy. We proposed to perform a systematic review and meta-analysis with metaregression to identify potential factors that can determine an increase in the high mortality and morbidity that characterize these surgical procedures. MEDLINE and Embase were searched for relevant studies. Twelve studies were eligible according to our inclusion criteria. TAVR explantation was confirmed as a procedure with high 30-day mortality (0.17; 95% CI, 0.14-0.21) and morbidity (stroke incidence 5%; 95% CI, 0.04-0.07; kidney injury incidence 16%; 95% CI, 0.11-0.24). The type of transcatheter valve implanted during the index procedure did not influence the outcomes after surgical explantation. The role of these high-risk operations is growing, and it will likely expand in the coming years. Specific tools for risk stratification are required.

A Case of CABG in a Patient with High Risk of Coronary Obstruction during TAV-in-TAV

A 94-year-old man who underwent transcatheter aortic valve (TAV) replacement 6 years ago was admitted because of exertional dyspnea. Transthoracic echocardiography revealed severe aortic regurgitation owing to TAV dysfunction. The patient was considered to have a high risk of occlusion of the sinus of Valsalva during TAV-in-TAV. Therefore, we performed TAV-in-TAV concomitant with coronary artery bypass grafting (CABG). The postoperative course was uneventful, and computed tomography 9 months later revealed patency of both the grafts. Concomitant CABG could be considered as one of the options in patients with a high risk of coronary occlusion during TAV-in-TAV.

Impact of transcatheter heart valve type on outcomes of surgical explantation after failed transcatheter aortic valve replacement: the EXPLANT-TAVR international registry

BACKGROUND

There are limited data on the impact of transcatheter heart valve (THV) type on the outcomes of surgical explantation after THV failure.

AIMS

We sought to determine the outcomes of transcatheter aortic valve replacement (TAVR) explantation for failed balloon-expandable valves (BEV) versus self-expanding valves (SEV).

METHODS

From November 2009 to February 2022, 401 patients across 42 centres in the EXPLANT-TAVR registry underwent TAVR explantation during a separate admission from the initial TAVR. Mechanically expandable valves (N=10, 2.5%) were excluded. The outcomes of TAVR explantation were compared for 202 (51.7%) failed BEV and 189 (48.3%) failed SEV.

RESULTS

Among 391 patients analysed (mean age: 73.0±9.8 years; 33.8% female), the median time from index TAVR to TAVR explantation was 13.3 months (interquartile range 5.1-34.8), with no differences between groups. Indications for TAVR explantation included endocarditis (36.0% failed SEV vs 55.4% failed BEV; p<0.001), paravalvular leak (21.2% vs 11.9%; p=0.014), structural valve deterioration (30.2% vs 21.8%; p=0.065) and prosthesis-patient mismatch (8.5% vs 10.4%; p=0.61). The SEV group trended fewer urgent/emergency surgeries (52.0% vs 62.3%; p=0.057) and more root replacement (15.3% vs 7.4%; p=0.016). Concomitant cardiac procedures were performed in 57.8% of patients, including coronary artery bypass graft (24.8%), and mitral (38.9%) and tricuspid (14.6%) valve surgery, with no differences between groups. In-hospital, 30-day, and 1-year mortality and stroke rates were similar between groups (allp>0.05), with no differences in cumulative mortality at 3 years (log-rank p=0.95). On multivariable analysis, concomitant mitral surgery was an independent predictor of 1-year mortality after BEV explant (hazard ratio [HR] 2.00, 95% confidence interval [CI]: 1.07-3.72) and SEV explant (HR 2.00, 95% CI: 1.08-3.69).

CONCLUSIONS

In the EXPLANT-TAVR global registry, BEV and SEV groups had different indications for surgical explantation, with more root replacements in SEV failure, but no differences in midterm mortality and morbidities. Further refinement of TAVR explantation techniques are important to improving outcomes.

Redo-TAVR: Essential Concepts, Updated Data and Current Gaps in Evidence

Within the last two decades, transcatheter aortic valve replacement (TAVR) has transformed the treatment strategy for symptomatic severe aortic stenosis (AS), representing a less invasive alternative to traditional open-chest surgery. With time, advances in device features, imaging planning, and implantation techniques have contributed to an improvement in safety as well as a reduction in procedural complications. This has led to the expansion of TAVR to lower-risk patients, where TAVR has shown favorable outcomes compared to surgical aortic valve replacement (SAVR). As TAVR expands to younger and lower-risk patients with longer life expectancies, the need for reintervention for failing transcatheter heart valves is expected to increase. Redo-TAVR has gained increasing relevance in the lifetime management of AS as one of the treatment strategies available for structural valve dysfunction (SVD). However, some issues are associated with this approach, including coronary re-access and the risk of coronary obstruction. In this review, we provide essential concepts to properly select candidates for Redo-TAVR, updated data on clinical outcomes and complication rates, and current gaps in evidence.

Explant vs Redo-TAVR After Transcatheter Valve Failure: Mid-Term Outcomes From the EXPLANTORREDO-TAVR International Registry

BACKGROUND

Valve reintervention after transcatheter aortic valve replacement (TAVR) failure has not been studied in detail.

OBJECTIVES

The authors sought to determine outcomes of TAVR surgical explantation (TAVR-explant) vs redo-TAVR because they are largely unknown.

METHODS

From May 2009 to February 2022, 396 patients in the international EXPLANTORREDO-TAVR registry underwent TAVR-explant (181, 46.4%) or redo-TAVR (215, 54.3%) for transcatheter heart valve (THV) failure during a separate admission from the initial TAVR. Outcomes were reported at 30 days and 1 year.

RESULTS

The incidence of reintervention after THV failure was 0.59% with increasing volume during the study period. Median time from index-TAVR to reintervention was shorter in TAVR-explant vs redo-TAVR (17.6 months [IQR: 5.0-40.7 months] vs 45.7 months [IQR: 10.6-75.6 months]; P < 0.001], respectively. TAVR-explant had more prosthesis-patient mismatch (17.1% vs 0.5%; P < 0.001) as the indication for reintervention, whereas redo-TAVR had more structural valve degeneration (63.7% vs 51.9%; P = 0.023), with a similar incidence of ≥moderate paravalvular leak between groups (28.7% vs 32.8% in redo-TAVR; P = 0.44). There was a similar proportion of balloon-expandable THV failures (39.8% TAVR-explant vs 40.5% redo-TAVR; P = 0.92). Median follow-up was 11.3 (IQR: 1.6-27.1 months) after reintervention. Compared with redo-TAVR, TAVR-explant had higher mortality at 30 days (13.6% vs 3.4%; P < 0.001) and 1 year (32.4% vs 15.4%; P = 0.001), with similar stroke rates between groups. On landmark analysis, mortality was similar between groups after 30 days (P = 0.91).

CONCLUSIONS

In this first report of the EXPLANTORREDO-TAVR global registry, TAVR-explant had a shorter median time to reintervention, with less structural valve degeneration, more prosthesis-patient mismatch, and similar paravalvular leak rates compared with redo-TAVR. TAVR-explant had higher mortality at 30 days and 1 year, but similar rates on landmark analysis after 30 days.

Lifetime management of patients with symptomatic severe aortic stenosis: a computed tomography simulation study

BACKGROUND

Given enough time, transcatheter heart valves (THVs) will degenerate and may require reintervention. Redo transcatheter aortic valve implantation (TAVI) is an attractive strategy but carries a risk of coronary obstruction.

AIMS

We sought to predict how many TAVIs patients could undergo in their lifetime using computed tomography (CT) simulation.

METHODS

We analysed paired CT scans (baseline and 30 days post-TAVI) from patients in the LRT trial and EPROMPT registry. We implanted virtual THVs on baseline CTs, comparing predicted valve-to-coronary (VTC) distances to 30-day CT VTC distances to evaluate the accuracy of CT simulation. We then simulated implantation of a second virtual THV within the first to estimate the risk of coronary obstruction due to sinus sequestration and the need for leaflet modification.

RESULTS

We included 213 patients with evaluable paired CTs. There was good agreement between virtual (baseline) and actual (30 days) CT measurements. CT simulation of TAVI followed by redo TAVI predicted low coronary obstruction risk in 25.4% of patients and high risk, likely necessitating leaflet modification, in 27.7%, regardless of THV type. The remaining 46.9% could undergo redo TAVI so long as the first THV was balloon-expandable but would likely require leaflet modification if the first THV was self-expanding.

CONCLUSIONS

Using cardiac CT simulation, it is possible to predict whether a patient can undergo multiple TAVI procedures in their lifetime. Those who cannot may prefer to undergo surgery first. CT simulation could provide a personalised lifetime management strategy for younger patients with symptomatic severe aortic stenosis and inform decision-making.

CLINICALTRIALS

gov: NCT02628899; ClinicalTrials.gov: NCT03557242; ClinicalTrials.gov: NCT03423459.