Learning curves for transapical transcatheter aortic valve replacement in the PARTNER-I trial: Technical performance, success, and safety

Redefining "low risk": Outcomes of surgical aortic valve replacement in low-risk patients in the transcatheter aortic valve replacement era

OBJECTIVES

Guidelines suggest aortic valve replacement (AVR) for low-risk asymptomatic patients. Indications for transcatheter AVR now include low-risk patients, making it imperative to understand state-of-the-art surgical AVR (SAVR) in this population. Therefore, we compared SAVR outcomes in low-risk patients with those expected from Society of Thoracic Surgeons (STS) models and assessed their intermediate-term survival.

METHODS

From January 2005 to January 2017, 3493 isolated SAVRs were performed in 3474 patients with STS predicted risk of mortality <4%. Observed operative mortality and composite major morbidity or mortality were compared with STS-expected outcomes according to calendar year of surgery. Logistic regression analysis was used to identify risk factors for these outcomes. Patients were followed for time-related mortality.

RESULTS

With 15 observed operative deaths (0.43%) compared with 55 expected (1.6%), the observed:expected ratio was 0.27 for mortality (95% confidence interval [CI], 0.14-0.42), stroke 0.65 (95% CI, 0.41-0.89), and reoperation 0.50 (95% CI, 0.42-0.60). Major morbidity or mortality steadily declined, with probabilities of 8.6%, 6.7%, and 5.2% in 2006, 2011, and 2016, respectively, while STS-expected risk remained at approximately 12%. Mitral valve regurgitation, ventricular hypertrophy, pulmonary, renal, and hepatic failure, coronary artery disease, and earlier surgery date were residual risk factors. Survival was 98%, 91%, and 82% at 1, 5, and 9 years, respectively, superior to that predicted for the US age-race-sex-matched population.

CONCLUSIONS

STS risk models overestimate contemporary SAVR risk at a high-volume center, supporting efforts to create a more agile quality assessment program. SAVR in low-risk patients provides durable survival benefit, supporting early surgery and providing a benchmark for transcatheter AVR.

Access options for transcatheter mitral valve implantation in patients with prior surgical bioprosthesis

Background

Transcatheter mitral valve-in-valve (TMVIV) procedure, either transapical (TA) or trans-septal (TS) has become a valuable alternative to conventional redo surgery in case of failing mitral bioprosthesis with good clinical outcomes. Here we present our fourteen-year institutional experience.

Methods

All consecutive patients treated with TMVIV with either TA or TS access at our centre between July 2007 and July 2020 were included. Periprocedural and 30-day follow-up (FU) results are reported and TA and TS data are compared.

Results

Eighty-two patients were included, of those 60 (73.2%) were TA while 22 (26.8%) were TS. Men represented 51.2% of the population with a mean age of 77.3±9.0 years. STS score and EuroSCORE II were 11.4%±6.2% and 11.5%±6.5% respectively. Baseline characteristics of TA and TS groups were comparable. TMVIV was performed at a median time of 9.3 years [interquartile range (IQR), 7.9-12.0 days] from the initial mitral valve surgery. Balloon expandable transcatheter heart valve (THV) prostheses (Edwards LifeSciences Corp., Irvine, CA, USA) were used exclusively. Technical success was 97.6% (96.7% and 100.0% for TA and TS respectively) with two (2.4%) periprocedural death, both in the TA group (P=0.533). We observed four (4.9%) left ventricular outflow tract (LVOT) obstructions with one being hemodynamically significant. Six (7.3%) major bleeding occurred in the TA group, not significantly different from TS group (P=0.279). The median length of stay was 6 days (IQR, 4-12 days, 1.5 vs. 7.0 days for TS and TA groups respectively, P=0.001). The overall 30-day mortality rate was 3.7%. We also observed three (3.7%) structural valve deteriorations and in one (1.2%) case the patient required redo mitral surgery at two months. Eighty-seven-point-eight percent of patients were I-II New York Heart Association (NYHA) class. At 30-day FU mean transmitral valve gradient was 7.3±2.7 mmHg and one patient (1.2%) had mitral regurgitation greater than mild. TA and TS groups were comparable.

Conclusions

Our 14-year single-center experience with TMVIV confirms procedural safety and is an effective alternative to redo surgery with comparable results with both TA and TS. With device, technical improvements and increasing operators' experience, TS is the preferred option for TMVIV. However, in some highly selected patient, TA may still play an important role.

Transcatheter Aortic Valve Implantation in Patients Who Cannot Undergo Transfemoral Access

INTRODUCTION

 Though transfemoral (TF) access has emerged as a gold standard access for patients with aortic stenosis who undergo transcatheter aortic valve implantation (TAVI), there has been no study that has characterized patients who cannot undergo TF access in detail. We aim to evaluate the contraindications for TF access, their incidence, classify them, and provide the outcomes of patients who failed to be TF candidates.

METHODS

 From 925 patients who underwent TAVI between February 2014 and May 2020 at our heart center, 130 patients failed to be TF candidates and underwent transapical-transcatheter aortic valve implantation (TA-TAVI). In this study, we included all those patients who failed to be TF candidates and underwent TA-TAVI using the third-generation balloon expandable valve (Edwards SAPIEN 3 valve [S3]) (116 patients; STS score 6.07 ± 4.4; age 79.4 ± 7).

RESULTS

 The incidence of patients unsuitable for TF access at our heart center was 14%. We classified this TAVI population into absolute contraindication for TF access n = 84 (72.5%) and increased interventional risk for TF access n = 32 (27.5%). After TA-TAVI of this specific population using S3, the in-hospital mortality and stroke were 1.7 and 1.7%, respectively. The vascular injury rate was 1.7%. We registered no paravalvular leakage ≥2. The pacemaker rate was 7.4%. The mean transvalvular pressure gradient was 8.7 mm Hg.

CONCLUSION

 The incidence of patients who cannot undergo TF access or who are at high interventional risk is considerably high. TA-TAVI, supported with sufficient interventional experience and appropriate valve system, represents an excellent alternative for patients with distinct vasculopathy.

Short- and Long-Term Outcome after Emergent Cardiac Surgery during Transcatheter Aortic Valve Implantation

Objective: Our study aimed to evaluate short- and long-term outcomes of patients who required emergent conversion from transcatheter aortic valve implantation (TAVI) to open surgery. Besides, the reasons and procedural settings of emergent cardiac surgery (ECS) were also reported.

Methods: We retrospectively reviewed the patients who underwent TAVI in our institution between 2012 and 2019 and collected the clinical data of cases who converted from TAVI to bail-out surgery. Telephone and outpatient follow-ups were performed.

Results: Of 516 TAVI patients, 20 required ECS, and the bail-out surgery occurred less frequently with the increase in TAVI volume. The most common reason for conversion was left ventricular perforation (7/20, 35.0%). Thirty-day mortality was 35.0% in ECS patients. Kaplan–Meier survival curves showed that the cumulative survival rate was 65.0% at 1 year, 50.1% at 5 years in all ECS patients, and 77.1% at 5 years in patients who survived over 30 days after conversion.

Conclusion: Although the bail-out operation was performed immediately after TAVI abortion, ECS still associated with high 30-day mortality. The long-term survival benefit was seen in patients surviving from bail-out surgery. An experienced TAVI team is of crucial importance in avoiding ECS-related life-threatening complications and providing effective salvage surgery.

The effect of transcatheter aortic valve implantation approaches on mortality

OBJECTIVES

We aimed to evaluate the effect of transcatheter aortic valve implantation (TAVI) approaches on mortality and identify effect modifiers and predictors for mortality.

BACKGROUND

Alternative access routes to transfemoral (TF) TAVI include the surgical intra-thoracic direct-aortic (DA) and transapical (TA) approach. TA TAVI has been associated with a higher mortality rate. We hypothesized that this is related to effect modifiers, in particular the left ventricular ejection fraction (LVEF).

METHODS

This multicentre study derived its data from prospective registries. To adjust for confounders, we used propensity-score based, stabilized inverse probability weighted Cox regression models.

RESULTS

In total, 5,910 patients underwent TAVI via TF (N = 4,072), DA (N = 524), and TA (N = 1,314) access. Compared to TF, 30-day mortality was increased among DA (HR 1.87, 95%CI 1.26-2.78, p = .002) and TA (HR 3.34, 95%CI 2.28-4.89, p < .001) cases. Compared to TF, 5-year mortality was increased among TA cases (HR 1.50, 95%CI 1.24-1.83, p < .001). None of the variables showed a significant interaction between the approaches and mortality. An impaired LVEF (≤35%) increased mortality in all approaches.

CONCLUSIONS

The surgical intra-thoracic TA and DA TAVI are both associated with a higher 30-day mortality than TF TAVI. TA TAVI is associated with a higher 5-year mortality than TF TAVI. The DA approach may therefore have some advantages over the TA approach when TF access is not feasible.

Learning curve for transcatheter aortic valve replacement for native aortic regurgitation: Safety and technical performance study

Background

Transcatheter aortic valve replacement (TAVR) is a fundamentally new procedure for the treatment of native aortic regurgitation (AR). The number of cases needed to gain proficiency with the procedure is unknown.

Hypothesis

This study aimed to evaluate the learning curve for TAVR for native AR.

Methods

This study retrospectively reviewed a prospective database from 134 consecutive native AR patients who underwent the J‐valve TAVR system, which performed by a single team interventional cardiologist. The cumulative sum (CUSUM) method was used to analyze the learning curve. Patients were divided into two groups in chronological order, defined by the surgeon's early (group 1: the first 52 cases) and skilled (group 2: the next 82 cases) experience. Demographic data, intraoperative characteristics, and short‐term surgical outcomes were compared between the two groups.

Results

CUSUM plots revealed decreasing procedure time and fluoroscopy time after patients 52 and 43, respectively. The patient date consistently demonstrated that high‐risk scores and major perioperative parameters were comparable between the two groups. The use of contrast dye (group 1, 94.22 ± 30.07 mL; group 2, 70.43 ± 15.02 mL, P<.05), total procedure time (group 1, 84.96 ± 17.76 minutes; group 2, 59.95 ± 12.83 minutes, P<.05), and fluoroscopy time (group 1, 11.52 ± 3.81 minutes; group 2, 6.47 ± 1.53 minutes, P<.05) were significantly reduced in group 2. The overall device success rate in group 1 was 96.2% vs 96.3% in group 2 and remained high (P = 1.0). The overall 30‐day mortality was 3.8% in group 2 (group 1, 0 to group 2, 3.8%; P = .16). The complications rate, such as pulmonary hypertension, chronic kidney disease, and coronary artery disease were higher in group 2.

Conclusions

For a surgeon without previous TAVR experience, 52 cases of performance is the minimal requirement to gain the proficiency of TAVR for native AR. The skilled surgeons have been observed with reduced procedural time, fluoroscopy times, radiation exposure dose, and contrast volume usage. However, the overall prognosis was not significantly different between the two groups.

Comparison of the Transarterial and Transthoracic Approaches in Nontransfemoral Transcatheter Aortic Valve Implantation

Transfemoral approach stands as the reference access-route for transcatheter aortic valve implantation (TAVI). Nonetheless, alternatives approaches are still needed in a significant proportion of patients. This study aimed at comparing outcomes between transthoracic-approach (transapical or transaortic) and transarterial-approach (transcarotid or subclavian) TAVI. Data from 191 consecutive patients who underwent surgical-approach TAVI from May 2009 to September 2017 were analyzed. Patients were allocated in 2 groups according to the approach. The primary end point was the 30-day composite of death of any cause, need for open surgery, tamponade, stroke, major or life-threatening bleeding, stage 2 or 3 acute kidney injury, coronary obstruction, or major vascular complications. During the study period, 104 patients underwent transthoracic TAVI (transapical: 60.6%, transaortic: 39.4%) whereas 87 patients underwent transarterial TAVI (subclavian: 83.9%, transcarotid: 16.1%). Logistic EuroSCORE I tended to be higher in transthoracic-TAVI recipients. In-hospital and 30-day composite end point rates were 25.0% and 11.5% (p = 0.025), and 26.0% and 14.9% (p = 0.075) for the transthoracic and transarterial cohorts, respectively. Propensity score-adjusted logistic regression demonstrated no significant detrimental association between the 30-day composite end point and transthoracic access (odds ratio 2.12 95% confidence interval 0.70 to 6.42; p = 0.18). Transarterial TAVI was associated with a shorter length of stay (median: 6 vs 7 days, p <0.001). TAVI approach was not an independent predictor of midterm mortality. In conclusion, nontransfemoral transarterial-approach TAVI is safe, feasible, and associated with comparable rates of major perioperative complications, and midterm mortality compared with transthoracic-approach TAVI.

TAVR Procedural Volumes and Patient Outcomes: Analysis of Recent Data

In less than 15 years, transcatheter aortic valve replacement (TAVR) has progressed from a procedure of last resort in patients at prohibitively high perioperative risk for major morbidity and mortality from surgical valve replacement to a viable alternative option to surgery in most patients with native (non-bicuspid) aortic valve stenosis. The number of medical centers offering TAVR has rapidly proliferated. There is mounting evidence that there are variations in patient outcomes associated with the yearly number of TAVR cases performed at each respective center. This review outlines the evolution of TAVR indications, common complications, the current literature addressing the association between procedural volumes and patient outcomes in TAVR, and offers a synopsis of risk factor assessment for patients considered for TAVR.

Operational and Institutional Recommendations and Requirements for TAVR: A Review of Expert Consensus and the Impact on Health Care Policy

When transcatheter aortic valve replacement (TAVR) was first approved for use in the United States in 2012, multiple leading surgical and cardiology societies were tasked with creating recommendations and requirements for operators and institutions starting and maintaining TAVR programs. Creation of this consensus document was challenging due to limited experience with this new technology, and a lack of robust centralized data that could be used to validate outcome measures and create benchmarks for self-assessment and improvement. Despite these limitations, this document provided government agencies a framework for regulation that ultimately determined requirements for Medicare payment for TAVR and therefore greatly determined how and where care was delivered for patients with aortic stenosis. After the proliferation of TAVR institutions throughout the US and with data from more than 100,000 cases in the STS/ACC Transcatheter Valve Therapies TM Registry, leaders of the same societies reconvened in 2018 to update their consensus document. The new recommendations include suggested personnel, facilities, training, and assessment of outcomes and competencies required to run a safe and efficient TAVR program. This article seeks to detail the changes from the original consensus document with a particular focus on issues relevant to cardiac anesthesiologists as well as important healthcare policy ramifications for patients and providers in the United States.

Transcatheter Aortic Valve-in-Valve Procedure in Patients with Bioprosthetic Structural Valve Deterioration

Surgical aortic valve replacement is the gold standard procedure to treat patients with severe, symptomatic aortic valve stenosis or insufficiency. Bioprosthetic valves are used for surgical aortic valve replacement with a much greater prevalence than mechanical valves. However, bioprosthetic valves may fail over time because of structural valve deterioration; this often requires intervention due to severe bioprosthetic valve stenosis or regurgitation or a combination of both. In select patients, transcatheter aortic valve replacement is an alternative to surgical aortic valve replacement. Transcatheter valve-in-valve (ViV) replacement is performed by implanting a transcatheter heart valve within a failing bioprosthetic valve. The transcatheter ViV operation is a less invasive procedure compared with reoperative surgical aortic valve replacement, but it has been associated with specific complications and requires extensive preoperative work-up and planning by the heart team. Data from experimental studies and analyses of results from clinical procedures have led to strategies to improve outcomes of these procedures. The type, size, and implant position of the transcatheter valve can be optimized for individual patients with knowledge of detailed dimensions of the surgical valve and radiographic and echocardiographic measurements of the patient's anatomy. Understanding the complexities of the ViV procedure can lead surgeons to make choices during the original surgical valve implantation that can make a future ViV operation more technically feasible years before it is required.

Learning Curve for Transcatheter Aortic Valve Implantation Under a Controlled Introduction System - Initial Analysis of a Japanese Nationwide Registry

BACKGROUND

The introduction of transcatheter aortic valve implantation (TAVI) into Japan was strictly controlled to optimize patient outcomes. The goal of this study was to assess if increasing experience during the introduction of this procedure was associated with outcomes.Methods and Results:The initial 1,752 patients registered in the Japanese national TAVI registry were included in the study. The association between operator procedure number and incidence of the early safety endpoint at 30 days (ESE30) as defined in the Valve Academic Research Consortium-2 consensus document was evaluated. Patients were divided into 4 groups by quartiles of procedure count (Groups I-IV in order of increasing number of procedures). Median patient age was 85 years, and 30.5% were male. The 30-day mortality rate was 1.4% (n=24), and 78 patients (7.9%) experienced 95 ESE30. Among the variables included in the model, ESE30 was associated with non-transfemoral approach (P=0.004), renal dysfunction (Cr >2.0 mg/dL) (P=0.01) and NYHA class III/IV (P=0.04). ESE30 incidence was not significantly different between Groups I-III and Group IV. Spline plots demonstrated that experience of 15-20 cases in total was needed to achieve a consistent low risk of ESE30.

CONCLUSIONS

Increasing experience was associated with better outcomes, but to a lesser degree than in previous reports. Our findings suggested that the risks associated with the learning curve process were appropriately mitigated.

Transcatheter Aortic Valve Replacement: Efficiency and Safety Improvements With Progressive Experience and Improved Technology

OBJECTIVE

Transcatheter aortic valve replacement is now commercially available for intermediate-risk, high-risk, or inoperable patients with severe aortic stenosis. In this study, we investigated change in the safety and efficiency of the transcatheter aortic valve replacement procedure at our institution and patient outcomes comparing our first 100, second 100, and last 100 patients.

METHODS

From March 2012 to June 2016, 544 patients underwent transcatheter aortic valve replacement at our center. Three hundred patients were selected for this study and were categorized in the following three groups: group A, first to 100th patient; group B, 101st to 200th patient; and group C, 444th to 544th patient. Preoperative, intraoperative, and postoperative data were collected.

RESULTS

Three hundred patients, 162 male (54%) male and 138 female (46%) with a mean ± SD age of 79.10 ± 8.93 years and mean ± SD society of thoracic surgeons' risk score of 7.47 ± 0.76 were included. Fluoroscopy time, operation time, and incision time significantly decreased form group A to group C (all P < 0.05). Mean of contrast volume was also the highest in group A and the lowest in group C (P < 0.001). Acute kidney injury rate was 26% (n = 26) in group A versus 23% (n = 23) in group B (P = 0.743), and only one patient in group C (group C vs. group B, P < 0.001). Strokes declined over time: five (5%) stroke in group A; two (2%) stroke in group B, and no patient in group C (group C vs. group B, P = 0.1, and group C vs. group A, P = 0.059). In-hospital mortality was 5% (n = 5) in group A, 4% (n = 4) in group B, and 1% in group C (P = 0.21).

CONCLUSIONS

Progressive experience and technology advances with transcatheter aortic valve replacement procedures improved operators' expertise, making the transcatheter aortic valve replacement more efficient and safer over time.

Avoiding the Learning Curve for Transcatheter Aortic Valve Replacement

Objectives. To evaluate whether collaboration between existing and new transcatheter aortic valve replacement (TAVR) programs could help reduce the number of cases needed to achieve optimal efficiency. Background. There is a well-documented learning curve for achieving procedural efficiency and safety in TAVR procedures. Methods. A multidisciplinary collaboration was established between the Minneapolis VA Medical Center (new program) and the University of Minnesota (established program since 2012, n = 219) 1 year prior to launching the new program. Results. 269 patients treated with TAVR (50 treated in the first year at the new program). Mean age was 76 (±18) years and STS score was 6.8 (±6). Access included transfemoral (n = 35, 70%), transapical (n = 8, 16%), transaortic (n = 2, 4%), and subclavian (n = 5, 10%) types. Procedural efficiency (procedural time 158 ± 59 versus 148 ± 62, p = 0.27), device success (96% versus 87%, p = 0.08), length of stay (5 ± 3 versus 6 ± 7 days, p = 0.10), and safety (in hospital mortality 4% versus 6%, p = 0.75) were similar between programs. We found no difference in outcome measures between the first and last 25 patients treated during the first year of the new program. Conclusions. Establishing a partnership with an established program can help mitigate the learning curve associated with these complex procedures.