Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: Technical performance

Radiation Exposure to the Interventional Echocardiographers and Sonographers: A Call to Action

Interventional echocardiography is a rapidly growing field within the disciplines of cardiology and anesthesiology, with the rise of advanced transcatheter procedures making skilled imagers more important than ever. However, these procedures also involve frequent manipulation of the transesophageal echocardiography probe, which means interventional echocardiographers (IEs) are at risk of long-term occupational radiation exposure. Studies have shown that radiation exposure is linked to various health issues, including cancer, cataracts, hypertension, hyperlipidemia, endothelial dysfunction, vascular aging, and early atherosclerosis. While there is increasing awareness of the occupational radiation dose limits and the need for better shielding methods, the importance of radiation safety for the IE is still not sufficiently prioritized in most cardiac catheterization laboratories/hybrid operating rooms. This is partly due to a paucity of studies looking at long-term radiation exposure to the IE, as this field is newer than that of interventional cardiologists.

Learning Curve for Starting a Successful Single-Centre TAVR Programme with Multiple Devices: Early and Mid-Term Follow-Up

Aims: We report 30-day, 1-year, and 3-year outcomes for a new TAVR programme that used five different transcatheter heart valve (THV) systems. Methods: From 2014 to 2020, 122 consecutive patients with severe aortic stenosis (AS) received TAVR based on the Heart Team decision. Outcomes were analysed for the whole study population and in addition the first 63 patients (Cohort A, 2014 to 2019) were compared to the last 59 patients (Cohort B, 2019 to 2020). Outcomes included VARC-2 definitions and device performance assessed via transthoracic echocardiography by independent high-volume investigators. Results: The mean patient age was 77.9 ± 6.1 years old, and 48 (39.3%) were male. The mean logistic Euroscore II was 4.2 ± 4.5, and the mean STS score was 6.9 ± 4.68. The systems used were as follows: Medtronic Corevalve Evolute R/PRO (82 patients-67.2%); Abbott Portico (13-10.6%); Boston Scientific Lotus (10-8.2%); Meril Myval (11-9%); and Boston Scientific Neo Accurate (6-5%). Access was transfemoral (95.9% of patients); surgical cut down (18% vs. percutaneous 77.8%); subclavian (n = 2); trans-axillary (n = 2); and direct aorta (n = 1). VARC-2 outcomes were as follows: device success rate 97.5%; stroke rate 1.6%; major vascular complication 3.3%; permanent pacemaker implantation 12.4%. At discharge, the incidences of grade I and II aortic regurgitation were 39.95 and 55.5%, respectively. At one year, all-cause mortality was 7.4% without admissions for valve-related dysfunction. The 3-year all-cause mortality and all-stroke rates were 22.9% and 4.1%, respectively. Between the 1-year and 3-year follow-ups, valve-related dysfunction was detected in three patients; one had THV system endocarditis that led to death. There was a remarkable but statistically non-significant decrease in mortality from Cohort A to Cohort B [four (6.3%) vs. one patient (1.7%), p = 0.195] and major vascular complications occurred at a significantly higher rate in the Cohort B [zero (0%) vs. four (6.8% patient, p = 0.036)]. Overall, we found that using multiple devices was safe and allowed for a learning team to achieve a high device success rate from the beginning (97.5%). Conclusions: TAVR with different THV systems showed acceptable early and mid-term outcomes for survival, technical success, and valve-related adverse events in high-risk patients with significant AS, even in the learning curve phase.

Obesity and vascular complication in percutaneous transfemoral transcatheter aortic valve insertion

BACKGROUND

Obesity has been associated with an increased risk of vascular complication during percutaneous coronary intervention, but there are no data on the risk of vascular complication during percutaneous transfemoral transcatheter aortic valve insertion (TAVI).

OBJECTIVES

We hypothesized there would be a similar increased risk associated with TAVI.

METHODS

We reviewed the records of 1176 patients who received percutaneous transfemoral transcatheter aortic valve insertion from September 2015 to September 2020. All patients received 1) preoperative computed tomoraphy angiography assessment of the abdomen and pelvis to delineate iliofemoral artery anatomy, 2) ultrasound-guided percutaneous femoral arterial access, and 3) pre-closure of the delivery sheath femoral access site. Vascular complication was recorded based on definitions set forth by Valve Academic Research Consortium 3.

RESULTS

The median age of patients was 81 years, and 60% were men. The median body mass index (BMI) was 29 kg/m2 (range, 11-67), and 91 (8%) patients had a value ≥40 kg/m2 (i.e., morbid obesity). Delivery sheath size was 14-French in 859 (73%) patients, 16-French in 311 (26%), and 18-French in 6 (1%). Vascular complication occurred in 53 (5%) patients, including 39 (7%) among the first half of procedures and 14 (2%) among the second half (p < 0.001). When stratified by obesity status (BMI < or ≥30 kg/m2 , p < 0.001), the complication rate was 4% in nonobese patients and 5% in obese patients. Multivariable analysis showed no overall association between risk of vascular complication and BMI categories (p = 0.583)BMI continuous values (p = 0.529), or sheath size (p = 0.217).

CONCLUSIONS

Obesity is not associated with a vascular complication during percutaneous transfemoral transcatheter aortic valve insertion. The operation should not be denied in obese patients.

The effect of the learning curve on paravalvular aortic regurgitation and mid-term mortality in transfemoral transcatheter aortic valve implantation

OBJECTIVE

Paravalvular aortic regurgitation is an important independent mortality predictor in transcatheter aortic valve implantation (TAVI). Our study evaluated the association between paravalvular aortic regurgitation and mid-term mortality in relation with the learning curve, in patients with severe aortic stenosis who underwent transfemoral TAVI in the first 3 years since the establishment of the program.

METHODS

Patients with severe aortic stenosis who underwent transfemoral TAVI between 2017 and 2020 were included in the analysis. Paravalvular aortic regurgitation was assessed by transthoracic echocardiography at 48 hours after the procedure. All-cause mortality was evaluated after 30 days and at mid-term follow-up.

RESULTS

Paravalvular aortic regurgitation ≥grade II was associated with mid-term all-cause mortality (OR 4.4; 95%CI 1.82-11.55; p < 0.001), their prevalence declining after the first 60 cases. Baseline characteristics did not significantly differ in the first 60 patients from the rest of the cohort. Male sex (p = 0.006), advanced age (p = 0.04), coronary artery disease (p = 0.003), or elevated STS Score (p = 0.02) influenced mid-term survival. When adjusting for the presence of these factors, only age (OR 1.1; 95%CI 1.0-1.2), paravalvular aortic regurgitation ≥grade II (OR 3.9; 95%CI 1.3-12.9), and the number of days spent in the intensive care unit (OR 1.4; 95%CI 1.1-1.8) were independent predictors of mid-term all-cause mortality.

CONCLUSIONS

In a group of patients with severe aortic stenosis who underwent transfemoral TAVI in the first 3 years since the establishment of the program, paravalvular aortic regurgitation ≥grade II was associated with mid-term mortality, both declining after the first 60 cases.

Real World Performance Evaluation of Transcatheter Aortic Valve Implantation

Background: The aim of this research is to describe the performance over time of transcatheter aortic valve implantations (TAVIs) in a high-volume center with a contemporary, real-world population. Methods: Patients referred for TAVIs at the University Hospital of Verona were prospectively enrolled. By cumulative sum failures analysis (CUSUM), procedural-control curves for standardized combined endpoints—as defined by the Valve Academic Research Consortium-2 (VARC-2)—were calculated and analyzed over time. Acceptable and unacceptable limits were derived from recent studies on TAVI in intermediate and low-risk patients to fit the higher required standards for current indications. Results: A total of 910 patients were included. Baseline risk scores significantly reduced over time. Complete procedural control was obtained after approximately 125 and 190 cases for device success and early safety standardized combined endpoints, respectively. High risk patients (STS ≥ 8) had poorer outcomes, especially in terms of VARC-2 clinical efficacy, and required a higher case load to maintain in-control and proficient procedures. Clinically relevant single endpoints were all influenced by operator’s experience as well. Conclusions: Quality-control analysis for contemporary TAVI interventions based on standardized endpoints suggests the need for relevant operator’s experience to achieve and maintain optimal clinical results, especially in higher-risk subjects.

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.

A scoping review to identify competencies for transcatheter cardiovascular procedures

OBJECTIVES

Transcatheter procedures are increasingly being recognized as a priority for cardiac surgeons and cardiac surgery trainees. The optimal method of teaching these procedures during residency training has not been established. We used an evidence-based approach to systematically review the literature and identify competencies to inform future paradigms of transcatheter training in cardiac surgery.

METHODS

A scoping review was conducted to retrieve relevant literature on the performance of transcatheter cardiovascular procedures, identify competencies required by surgical residents learning to perform these procedures, and develop a preliminary list of competencies for consideration during transcatheter training. MEDLINE, Scopus, and ERIC were queried until April 1, 2020, using a systematic search strategy. No limitations were placed on publication date or type.

RESULTS

A total of 1456 sources of evidence were retrieved. After deduplication and screening, there remained 33 that were included in the scoping review, published between 2006 and 2020. The distribution of publication types included 10 comparative studies (30.3% of total), 8 societal statements (24.2% of total), 5 surveys and 5 opinion articles (each 15.2% of total), 2 editorials and 2 descriptions of a simulator (each 6.1% of total), and 1 narrative review (3.0% of total). From these, a total of 400 items were identified and organized into 97 competencies.

CONCLUSIONS

Evidence on the competencies required to perform transcatheter cardiovascular procedures is available from a variety of sources. The identified competencies may be a useful resource for developing curricula and teaching transcatheter procedures to cardiac surgery residents.

Resuscitation Opportunities for Fellows of Very Low Birth Weight Infants in the Vermont Oxford Network

BACKGROUND

Neonatal-perinatal medicine (NPM) fellowship programs must provide adequate delivery room (DR) experience to ensure that physicians can independently provide neonatal resuscitation to very low birth weight (VLBW) infants. The availability of learning opportunities is unknown.

METHODS

The number of VLBW (≤1500 g) and extremely low birth weight (ELBW) (<1000 g) deliveries, uses of continuous positive airway pressure, intubation, chest compressions, and epinephrine over 3 years at accredited civilian NPM fellowship program delivery hospitals were determined from the Vermont Oxford Network from 2012 to 2017. Using Poisson distributions, we estimated the expected probabilities of fellows experiencing a given number of cases over 3 years at each program.

RESULTS

Of the 94 NPM fellowships, 86 programs with 115 delivery hospitals and 62 699 VLBW deliveries (28 703 ELBW) were included. During a 3-year fellowship, the mean number of deliveries per fellow ranged from 14 to 214 (median: 60) for VLBWs and 7 to 107 (median: 27) for ELBWs. One-half of fellows were expected to see ≤23 ELBW deliveries and 52 VLBW deliveries, 24 instances of continuous positive airway pressure, 23 intubations, 2 instances of chest compressions, and 1 treatment with epinephrine.

CONCLUSIONS

The number of opportunities available to fellows for managing VLBW and ELBW infants in the DR is highly variable among programs. Fellows' exposure to key, high-risk DR procedures such as cardiopulmonary resuscitation is low at all programs. Fellowship programs should track fellow exposure to neonatal resuscitations in the DR and integrate supplemental learning opportunities. Given the low numbers, the number of new and existing NPM programs should be considered.

The learning curve in transcatheter aortic valve implantation clinical studies: A systematic review

Background

Transcatheter aortic-valve implantation (TAVI) has become an essential alternative to surgical aortic-valve replacement in the treatment of symptomatic severe aortic stenosis, and this procedure requires technical expertise. The aim of this study was to identify prospective studies on TAVI from the past 10 years, and then to analyze the quality of information reported about the learning curve.

Materials and methods

A systematic review of articles published between 2007 and 2017 was performed using PubMed and the EMBASE database. Prospective studies regarding TAVI were included. The quality of information reported about the learning curve was evaluated using the following criteria: mention of the learning curve, the description of a roll-in phase, the involvement of a proctor, and the number of patients suggested to maintain skills.

Results

A total of sixty-eight studies met the selection criteria and were suitable for analysis. The learning curve was addressed in approximately half of the articles (n = 37, 54 percent). However, the roll-in period was mentioned by only eight studies (12 percent) and with very few details. Furthermore, a proctorship was disclosed in three articles (4 percent) whereas twenty-five studies (37 percent) included authors that were proctors for manufacturers of TAVI.

Conclusion

Many prospective studies on TAVI over the past 10 years mention learning curves as a core component of successful TAVI procedures. However, the quality of information reported about the learning curve is relatively poor, and uniform guidance on how to properly assess the learning curve is still missing.

Long-Term Effects of Transcatheter Aortic Valve Implantation on Coronary Hemodynamics in Patients With Concomitant Coronary Artery Disease and Severe Aortic Stenosis

Background As younger patients are being considered for transcatheter aortic valve implantation (TAVI), the assessment and treatment of concomitant coronary artery disease is taking on increased importance. Methods and Results Thirteen contemporary lower-risk patients with TAVI with severe aortic stenosis (AS) and moderate-severe coronary lesions were included. Patients underwent assessment of coronary hemodynamics in the presence of severe AS (pre-TAVI), in the absence of severe AS (immediately post-TAVI), and at longer-term follow-up (6 months post-TAVI). Fractional flow reserve decreased from 0.85 (0.76-0.88) pre-TAVI to 0.79 (0.74-0.83) post-TAVI, and then to 0.71 (0.65-0.77) at 6-month follow-up (P<0.001 for all comparisons). Conversely, instantaneous wave-free ratio was not significantly different: 0.82 (0.80-0.90) pre-TAVI, 0.83 (0.77-0.88) post-TAVI, and 0.83 (0.73-0.89) at 6 months (P=0.735). These changes are explained by the underlying coronary flow. Hyperemic whole-cycle coronary flow (fractional flow reserve flow) increased from 26.36 cm/s (23.82-31.82 cm/s) pre-TAVI to 30.78 cm/s (29.70-34.68 cm/s) post-TAVI (P=0.012), to 40.20 cm/s (32.14-50.00 cm/s) at 6-month follow-up (P<0.001 for both comparisons). Resting flow during the wave-free period of diastole was not significantly different: 25.48 cm/s (21.12-33.65 cm/s) pre-TAVI, 24.54 cm/s (20.74-27.88 cm/s) post-TAVI, and 25.89 cm/s (22.57-28.96 cm/s) at 6 months (P=0.500). Conclusions TAVI acutely improves whole-cycle hyperemic coronary flow, with ongoing sustained improvements at longer-term follow-up. This enhanced response to hyperemic stimuli appears to make fractional flow reserve assessment less suitable for patients with severe AS. Conversely, resting diastolic flow is not significantly influenced by the presence of severe AS. Resting indices of coronary stenosis severity, therefore, appear to be more appropriate for this patient population, although large-scale prospective randomized trials will be required to determine the role of coronary physiology in patients with severe AS.

Outcomes of transcatheter aortic valve implantations in high-volume or low-volume centres in Germany

Objective

Transcatheter aortic valve implantation (TAVI) is the most common aortic valve replacement in Germany. Since 2015, to ensure high-quality procedures, hospitals in Germany and other countries that meet the minimum requirement of 50 interventions per centre are being certified to perform TAVI. This study analyses the impact of these requirements on case number and in-hospital outcomes.

Methods

All isolated TAVI procedures and in-hospital outcomes between 2008 and 2016 were identified by International Classification of Diseases (ICD) and the German Operation and Procedure Classification codes.

Results

73 467 isolated transfemoral and transapical TAVI procedures were performed in Germany between 2008 and 2016. During this period, the number of TAVI procedures per year rose steeply, whereas the overall rates of hospital mortality and complications declined. In 2008, the majority of procedures were performed in hospitals with fewer than 50 cases per year (54.63%). Until 2014, the share of patients treated in low-volume centres constantly decreased to 5.35%. After the revision of recommendations, it further declined to 1.99%. In the 2 years after the introduction of the minimum requirements on case numbers, patients were at decreased risk for in-hospital mortality when treated in a high-volume centre (risk-adjusted OR 0.62, p=0.012). The risk for other in-hospital outcomes (stroke, permanent pacemaker implantation and bleeding events) did not differ after risk adjustment (p=0.346, p=0.142 and p=0.633).

Conclusion

A minimum volume of 50 procedures per centre and year appears suitable to allow for sufficient routine and thus better in-hospital outcomes, while ensuring nationwide coverage of TAVI procedures.

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.

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.

Evolution of transcatheter aortic valve implantation over 7 years: results of a prospective single-centre registry of 2000 patients in a large municipal hospital (TAVIK Registry)

OBJECTIVES

Use of transcatheter aortic valve implantation (TAVI) to treat severe aortic stenosis (AS) has gained popularity, accompanied by an evolution of patient and clinical factors. We aimed to characterise changes and evaluate their impact on outcomes.

SETTING

In this single-centre, German TAVIK registry patients undergoing TAVI between 2008 and 2015 were documented prospectively.

PARTICIPANTS/INTERVENTIONS

2000 consecutive patients with AS undergoing TAVI were divided in four cohorts. 500 patients underwent TAVI in each of the following time bins: April 2008 to July 2010 (cohort I), July 2010 to April 2013 (cohort II), April 2012 to October 2013 (cohort III) and October 2013 to March 2015 (cohort IV).

RESULTS

The mean age was 81.8 years, without significant variation across cohorts. Compared with cohort I, prior MI (5.4%vs11.0%; p<0.001) and New York Heart Association class IV (10.0%vs3.6%; p<0.001) were less common in cohort IV. Across cohorts, there was a fall in EuroSCORE (24.3%-18.7%), frailty (48.4%-17.0%) and use of transapical access (43.6%-29.0%), while transfemoral access increased (56.4%-71.0%; p<0.001 for each). Periprocedurally, there was a fall in moderate/severe aortic regurgitation (3.2%-0.0%) and rate of unplanned cardiopulmonary bypass (4.0%-1.0%; both p<0.001). A similar trend applied to 30-day rate of major vascular complications (5.2%-1.8%; p=0.006), life-threatening bleeding (7.0%-3.0%; p<0.001) and cardiovascular mortality (4.4%-1.8%; p=0.020). One-year post-TAVI, mortality and stroke rates did not differ.

CONCLUSIONS

Evolution of TAVI between 2008 and 2015 saw a trend towards its usage in lower risk patients and rapid progression towards improved safety. Evaluation and refinement should now continue to further lessen stroke and pacemaker rates.

Outcomes and Safety of Transcatheter Aortic Valve Implantation With and Without Routine Use of Transesophageal Echocardiography

Transesophageal echocardiography (TEE) has been extensively used historically for Transcatheter aortic valve implantation (TAVI) but focus is shifting from routine use of TEE and general anesthesia to "as needed" use. We evaluated patients who had TAVI in our institution from September 2012 to February 2017. Decision for implantation and use of TEE during procedure was made by the structural heart team on a case-to-case basis, based on FDA approved indications. Data including procedural details, length of stay and rehospitalizations were obtained from all patients. TAVI was performed on 178 patients during the study period of which 104 of 178 had TEE during TAVI. Baseline characteristics were fairly comparable in both groups. Similar proportion of self-expanding and balloon expanding valves were deployed. Patients in TEE group had longer overall procedure time (107 minute vs 83 minute, p = 0.0002) and longer length of stay (5.01days vs 2.49days, p < 0.0001). Echocardiographic study postprocedure showed similar incidence of paravalvular leak and similar gradients and velocities across aortic valve. Rates of 30-day readmissions were similar in both groups. In conclusion, in this single-center retrospective analysis-TAVI without the 'routine use' of TEE was comparable with those done with TEE guidance in terms of periprocedural complications and 30-day readmissions. Overall procedure length and length of stay was predictably higher in the TEE group.

The learning curve associated with the implantation of the Nanostim leadless pacemaker

Purpose

Use of novel medical technologies, such as leadless pacemaker (LP) therapy, may be subjected to a learning curve effect. The objective of the current study was to assess the impact of operators’ experience on the occurrence of serious adverse device effects (SADE) and procedural efficiency.

Methods

Patients implanted with a Nanostim LP (Abbott, USA) within two prospective studies (i.e., LEADLESS ll IDE and Leadless Observational Study) were assessed. Patients were categorized into quartiles based on operator experience. Learning curve analysis included the comparison of SADE rates at 30 days post-implant per quartile and between patients in quartile 4 (> 10 implants) and patients in quartiles 1 through 3 (1–10 implants). Procedural efficiency was assessed based on procedure duration and repositioning attempts.

Results

Nanostim LP implant was performed in 1439 patients by 171 implanters at 60 centers in 10 countries. A total of 91 (6.4%) patients experienced a SADE in the first 30 days. SADE rates dropped from 7.4 to 4.5% (p = 0.038) after more than 10 implants per operator. Total procedure duration decreased from 30.9 ± 19.1 min in quartile 1 to 21.6 ± 13.2 min (p < 0.001) in quartile 4. The need for multiple repositionings during the LP procedure reduced in quartile 4 (14.8%), compared to quartiles 1 (26.8%; p < 0.001), 2 (26.6%; p < 0.001), and 3 (20.4%; p = 0.03).

Conclusions

Learning curves exist for Nanostim LP implantation. Procedure efficiency improved with increased operator experience, according to a decrease in the incidence of SADE, procedure duration, and repositioning attempts.

Electronic supplementary material

The online version of this article (10.1007/s10840-018-0438-8) contains supplementary material, which is available to authorized users.

Evolution of Procedural and Clinical Outcomes After Balloon-Expanding Transcatheter Aortic Valve Implantation In Canada (from the Early Canadian Experience and SOURCE XT Registries)

Transcatheter aortic valve implantation (TAVI) has evolved globally, yet its evolution and performance across the Canadian landscape have yet to be formally assessed. Patients captured within the early Canadian TAVI experience with a balloon-expanding valve (n = 339; 2005 to 2009) and those enrolled in the Canadian SOURCE XT registry (n = 415; 2012 to 2015) were systematically compared with respect to baseline clinical, echocardiographic, and procedural characteristics. Valve-related and clinical outcomes were compared across the 2 time periods according to standardized definitions. Notable baseline between-group differences were noted across time, with Society of Thoracic Surgeons Predicted Risk of Mortality score being lower in the SOURCE XT cohort compared with the earlier Canadian cohort (7.4 ± 6.6% vs 9.8 ± 6.4%, p <0.001). The SOURCE XT cohort underwent TAVI through the transfemoral approach more frequently than their earlier Canadian counterparts (75% vs 48%), at the expense of transapical access, with major access site vascular complications (2.7% vs 13%), and ≥mild residual aortic regurgitation (39% vs 69%) being significantly less frequent (p <0.001 for all). At 30-days, there were no significant differences in rates of stroke (1.9% vs 2.4%) or new pacemakers (5.8% vs 5.0%); however, 30-day and 1-year mortality rates were significantly lower in the SOURCE XT cohort (3.6% vs 10.4%; 13.0% vs 24.2%, respectively, p<0.001 for both). In conclusion, TAVIs evolution in Canada with a balloon-expanding valve coincided with more optimized patient selection and increasing use of transfemoral access, which along with increasing operator experience, contributed to improved procedural and longer term clinical outcomes.

Trends in patient characteristics and clinical outcome over 8 years of transcatheter aortic valve implantation

Aim

In the evolving field of transcatheter aortic valve implantations (TAVI) we aimed to gain insight into trends in patient and procedural characteristics as well as clinical outcome over an 8‑year period in a real-world TAVI population.

Methods

We performed a single-centre retrospective analysis of 1,011 consecutive patients in a prospectively acquired database. We divided the cohort into tertiles of 337 patients; first interval: January 2009–March 2013, second interval: March 2013–March 2015, third interval: March 2015–October 2016.

Results

Over time, a clear shift in patient selection was noticeable towards lower surgical risks including Society of Thoracic Surgeons predicted risk of mortality score and comorbidity. The frequency of transfemoral TAVI increased (from 66.5 to 77.4%, p = 0.0015). Device success improved (from 62.0 to 91.5%, p < 0.0001) as did the frequency of symptomatic relief (≥1 New York Heart Association class difference) (from 73.8 to 87.1%, p = 0.00025). Complication rates decreased, including in-hospital stroke (from 5.0 to 2.1%, p = 0.033) and pacemaker implantations (from 10.1 to 5.9%, p = 0.033). Thirty-day mortality decreased (from 11.0 to 2.4%, p < 0.0001); after adjustment for patient characteristics, a mortality-risk reduction of 72% was observed (adjusted hazard ratio [HR]: 0.28, 95% confidence interval [CI]: 0.13–0.62). One-year mortality rates decreased (from 23.4 to 11.4%), but this was no longer significant after a landmark point was set at 30 days (mortality from 31 days until 1 year) (adjusted HR: 0.69, 95% CI: 0.41–1.16, p = 0.16).

Conclusion

A clear shift towards a lower-risk TAVI population and improved clinical outcome was observed over an 8‑year period. Survival after TAVI improved impressively, mainly as a consequence of decreased 30-day mortality.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1129-x) contains supplementary material, which is available to authorized users.

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.

A proctoring system to manage the learning curve associated with the introduction of transcatheter aortic valve implantation in Japan

As transcatheter aortic valve implantation (TAVI) requires multidisciplinary collaboration, operators and the entire heart team must overcome a steep learning curve. A web-based screening and traditional on-site proctoring system were developed for the introduction of TAVI in Japan. To assess the learning curve involved with the introduction of TAVI under the supervision of a novel proctoring system. We divided 749 consecutive patients enrolled in the OCEAN-TAVI study between October 2013 and August 2015 into the trans-femoral (TF, n = 608) and transapical (TA, n = 141) approach groups to compare outcomes in patients who underwent TAVI during the early proctoring period (proctoring group) and after the procedures began to be performed independently (independent group). The primary endpoint was the rate of composite events regarding early safety (at 30 days) according to the valve academic research consortium-2 criteria. For TF-TAVI, the logistic EuroSCORE and the rate of peripheral artery disease were significantly lower during the independent period. The rate of device success significantly increased during the independent period (90.5 vs. 81.8%, p = 0.005). The rate of the primary endpoint was significantly reduced during the independent period compared to that during the proctoring period for TA-TAVI (21.3 vs. 37.9%, p = 0.031); however, no difference was observed for TF-TAVI (16.8 vs. 13.1%, p = 0.283). No deaths occurred within 30 days during the proctoring period for TF-TAVI. After adjustment using propensity score matching, the procedure time for TF-TAVI (88 ± 43 vs. 102 ± 36 min, p = 0.004) and the rate of life-threatening bleeding for TA-TAVI (3.6 vs. 25%, p = 0.026) reduced during the independent period compared to the values during the proctoring period. During the introduction of TAVI under the supervision of a new proctoring system in Japan, clinical outcomes and technical aspects improved significantly. There are differences in the steepness of the learning curve between TF-TAVI and TA-TAVI.

Regional Variation in Utilization, In-hospital Mortality, and Health-Care Resource Use of Transcatheter Aortic Valve Implantation in the United States

We queried the National Inpatient Sample database from 2012 to 2014 to identify all patients aged ≥18 years undergoing transcatheter aortic valve implantation (TAVI) in the United States. Regional differences in TAVI utilization, in-hospital mortality, and health-care resource use were analyzed. Of 41,025 TAVI procedures in the United States between 2012 and 2014, 10,390 were performed in the Northeast, 9,090 in the Midwest, 14,095 in the South, and 7,450 in the West. Overall, the number of TAVI implants per million adults increased from 24.8 in 2012 to 63.2 in 2014. The utilization of TAVI increased during the study period in all 4 geographic regions, with the number of implants per million adults being highest in the Northeast, followed by the Midwest, South, and West, respectively. Overall in-hospital mortality was 4.2%. Compared with the Northeast, risk-adjusted in-hospital mortality was higher in the Midwest (adjusted odds ratio [aOR] 1.26 [1.07 to 1.48]) and the South (aOR 1.61 [1.40 to 1.85]) and similar in the West (aOR 1.00 [0.84 to 1.18]). Average length of stay was shorter in all other regions compared with the Northeast. Among patients surviving to discharge, disposition to a skilled nursing facility or home health care was most common in the Northeast, whereas home discharge was most common in the West. Average hospital costs were highest in the West. In conclusion, we observed significant regional differences in TAVI utilization, in-hospital mortality, and health-care resource use in the United States. The findings of our study may have important policy implications and should provide an impetus to understand the source of this regional variation.

Transcatheter Aortic Valve Implantation Within Degenerated Aortic Surgical Bioprostheses: PARTNER 2 Valve-in-Valve Registry

BACKGROUND

Early experience with transcatheter aortic valve replacement (TAVR) within failed bioprosthetic surgical aortic valves has shown that valve-in-valve (VIV) TAVR is a feasible therapeutic option with acceptable acute procedural results.

OBJECTIVES

The authors examined 30-day and 1-year outcomes in a large cohort of high-risk patients undergoing VIV TAVR.

METHODS

Patients with symptomatic degeneration of surgical aortic bioprostheses at high risk (≥50% major morbidity or mortality) for reoperative surgery were prospectively enrolled in the multicenter PARTNER (Placement of Aortic Transcatheter Valves) 2 VIV trial and continued access registries.

RESULTS

Valve-in-valve procedures were performed in 365 patients (96 initial registry, 269 continued access patients). Mean age was 78.9 ± 10.2 years, and mean Society of Thoracic Surgeons score was 9.1 ± 4.7%. At 30 days, all-cause mortality was 2.7%, stroke was 2.7%, major vascular complication was 4.1%, conversion to surgery was 0.6%, coronary occlusion was 0.8%, and new pacemaker insertion was 1.9%. One-year all-cause mortality was 12.4%. Mortality fell from the initial registry to the subsequent continued access registry, both at 30 days (8.2% vs. 0.7%, respectively; p = 0.0001) and at 1 year (19.7% vs. 9.8%, respectively; p = 0.006). At 1 year, mean gradient was 17.6 mm Hg, and effective orifice area was 1.16 cm², with greater than mild paravalvular regurgitation of 1.9%. Left ventricular ejection fraction increased (50.6% to 54.2%), and mass index decreased (135.7 to 117.6 g/m²), with reductions in both mitral (34.9% vs. 12.7%) and tricuspid (31.8% vs. 21.2%) moderate or severe regurgitation (all p < 0.0001). Kansas City Cardiomyopathy Questionnaire score increased (mean: 43.1 to 77.0) and 6-min walk test distance results increased (mean: 163.6 to 252.3 m; both p < 0.0001).

CONCLUSIONS

In high-risk patients, TAVR for bioprosthetic aortic valve failure is associated with relatively low mortality and complication rates, improved hemodynamics, and excellent functional and quality-of-life outcomes at 1 year. (The PARTNER II Trial: Placement of AoRTic TraNscathetER Valves [PARTNER II]; NCT01314313).

Impact of operator experience and training strategy on procedural outcomes with leadless pacing: Insights from the Micra Transcatheter Pacing Study

BACKGROUND

Leadless pacemaker systems have been designed to avoid the need for a pocket and transvenous lead. However, delivery of this therapy requires a new catheter-based procedure. This study evaluates the role of operator experience and different training strategies on procedural outcomes.

METHODS

A total of 726 patients underwent implant attempt with the Micra transcatheter pacing system (TPS; Medtronic, Minneapolis, MN, USA) by 94 operators trained in a teaching laboratory using a simulator, cadaver, and large animal models (lab training) or locally at the hospital with simulator/demo model and proctorship (hospital training). Procedure success, procedure duration, fluoroscopy time, and safety outcomes were compared between training methods and experience (implant case number).

RESULTS

The Micra TPS procedure was successful in 99.2% of attempts and did not differ between the 55 operators trained in the lab setting and the 39 operators trained locally at the hospital (P = 0.189). Implant case number was also not a determinant of procedural success (P = 0.456). Each operator performed between one and 55 procedures. Procedure time and fluoroscopy duration decreased by 2.0% (P = 0.002) and 3.2% (P < 0.001) compared to the previous case. Major complication rate and pericardial effusion rate were not associated with case number (P = 0.755 and P = 0.620, respectively). There were no differences in the safety outcomes by training method.

CONCLUSIONS

Among a large group of operators, implantation success was high regardless of experience. While procedure duration and fluoroscopy times decreased with implant number, complications were low and not associated with case number. Procedure and safety outcomes were similar between distinct training methodologies.

Paravalvular Regurgitation after Transcatheter Aortic Valve Replacement: Comparing Transthoracic versus Transesophageal Echocardiographic Guidance

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is increasingly being performed in cardiac catheterization laboratories using transthoracic echocardiography (TTE) to guide valve deployment. The risk of paravalvular regurgitation (PVR) remains a concern.

METHODS

We retrospectively reviewed 454 consecutive patients (mean age, 82 ± 8; 58% male) who underwent transfemoral TAVR at Emory Healthcare from 2007 to 2014. Two hundred thirty-four patients underwent TAVR in the cardiac catheterization laboratory with TTE guidance (TTE-TAVR; mean Society of Thoracic Surgeons score, 10%), while 220 patients underwent the procedure in the hybrid operating room with transesophageal echocardiography (TEE) guidance (TEE-TAVR; mean Society of Thoracic Surgeons score, 11%). All patients received an Edwards valve (SAPIEN 55%, SAPIEN-XT 45%). Clinical and procedural characteristics, echocardiographic parameters, and incidence of PVR were compared.

RESULTS

The incidence of at least mild PVR at discharge was comparable between TTE-TAVR and TEE-TAVR (33% vs 38%, respectively; P = .326) and did not differ when stratified by valve type. However, in the TTE-TAVR group, there was a higher incidence of second valve implantation (7% vs 2%; P = .026) and postdilation (38% vs 17%; P < .001) during the procedure. Although not independently associated with PVR at discharge (odds ratio = 1.12; 95% CI, 0.69-1.79), TTE-TAVR was associated with PVR-related events: the combined outcome of mild PVR at discharge, intraprocedural postdilation, and second valve insertion (odds ratio = 1.58; 95% CI, 1.01-2.46). There were no significant differences in PVR at 30 days, 6 months, and 1 year between the two groups.

CONCLUSIONS

TTE-TAVR in a high-risk group of patients was associated with increased incidence of intraprocedure PVR-related events, although it was not associated with higher rates of PVR at follow-up. Multicenter randomized trials are required to confirm the cost-effectiveness and safety of TTE-TAVR.

Learning curves for TAVR: Not quite see one, do one teach one

The learning curve for TAVR is determined based on technical (procedural) data from PARTNER-1 Trial The number of cases needed to reach a learning curve for TAVR in PARTNER-1 was 50 for original sites and fell to 25 for late entering sites Analyses such as this is important in developing guidelines for other emerging technologies.

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.

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.

Patient-specific computer modelling - its role in the planning of transcatheter aortic valve implantation

Transcatheter aortic valve implantation is increasingly used to treat patients with severe aortic stenosis who are at increased risk for surgical aortic valve replacement and is projected to be the preferred treatment modality. As patient selection and operator experience have improved, it is hypothesised that device-host interactions will play a more dominant role in outcome. This, in combination with the increasing number of valve types and sizes, confronts the physician with the dilemma to choose the valve that best fits the individual patient. This necessitates the availability of pre-procedural computer simulation that is based upon the integration of the patient-specific anatomy, the physical and (bio)mechanical properties of the valve and recipient anatomy derived from in-vitro experiments. The objective of this paper is to present such a model and illustrate its potential clinical utility via a few case studies.

Learning Alternative Access Approaches for Transcatheter Aortic Valve Replacement: Implications for New Transcatheter Aortic Valve Replacement Centers

BACKGROUND

Smaller transcatheter aortic valve replacement (TAVR) delivery systems have increased the number of patients eligible for transfemoral procedures while decreasing the need for transaortic (TAo) or transapical (TA) access. As a result, newer TAVR centers are likely to have less exposure to these alternative access techniques, making it harder to achieve proficiency. The purpose of this study was to evaluate the learning curve for TAVR approaches and compare perioperative outcomes.

METHODS

From January 2008 to December 2014, 400 patients underwent TAVR (transfemoral, n = 179; TA, n = 120; and TAo, n = 101)). Learning curves were constructed using metrics of contrast utilization, procedural, and fluoroscopy times. Outcomes during the learning curve were compared with after proficiency was achieved.

RESULTS

Depending on the metric, learning curves for all three routes differed slightly but all demonstrated proficiency by the 50th case. There were no significant differences in procedural times whereas improvements in contrast use were most notable for TA (69 ± 40 mL versus 50 ± 23 mL, p = 0.002). For both TA and TAo, fewer patients received transfusions once proficiency was reached (62% versus 34%, p = 0.003, and 42% versus 14%, p = 0.002, respectively). No differences in 30-day or 1-year mortality were seen before or after proficiency was reached for any approach.

CONCLUSIONS

The learning curves for TA and TAo are distinct but technical proficiency begins to develop by 25 cases and becomes complete by 50 cases for both approaches. Given the relatively low volume of alternative access, achieving technical proficiency may take significant time. However, technical proficiency had no effect on 30-day or 1-year mortality for any access approach.