The Sky Is Not Falling: Surgical Perspectives on a New Transcatheter Paradigm.

The role of cardiac surgeons in the treatment of aortic valve disease is changing with the expansion of transcatheter aortic valve replacement. Recent trials in patients at low surgical risk will further this paradigm shift, and the future cardiac surgeons in this space remain uncertain. In this Viewpoint article, we discuss the role that surgeons can play in the future of structural heart medicine. We examine the potential effects of the low-risk transcatheter aortic valve replacement trials on overall operative volumes and how these effects may be limited through structured training programs and strong collaboration within the heart team. Finally, future considerations and cautions for the cardiac surgical community are discussed. The coming era presents an opportunity for growth, leadership, and strong interdisciplinary collaboration for the cardiac surgery community.

Performance of a Machine Learning Algorithm in Predicting Outcomes of Aortic Valve Replacement.

BACKGROUND: This study evaluated the performance of a machine learning (ML) algorithm in predicting outcomes of surgical aortic valve replacement (SAVR). METHODS: Adult patients undergoing isolated SAVR in The Society of Thoracic Surgeons (STS) National Database between 2007 and 2017 (n = 243,142) were randomly split 4:1 into training and validation sets. Outcomes that were evaluated were those for which STS models exist. The ML algorithm extreme gradient boosting (XGBoost) was used. Model calibration was measured by the ratio of observed to expected risk, calibration-in-the-large, and slope of calibration curve, and model discrimination was measured by the c-index. RESULTS: XGBoost demonstrated excellent calibration, with an average observed-to-expected ratio of 0.985, calibration-in-the-large of -0.017, and slope of calibration curve of 0.944. The c-index of XGBoost was significantly improved compared with STS models for 5 of 7 outcomes: operative mortality (77.1% [95% confidence interval {CI}, 75.8% to 78.4%] vs 76.2% [95% CI, 75.0% to 77.6%]; P = .007), prolonged ventilation (73.9% [95% CI, 73.1% to 74.6%] vs 72.6% [95% CI, 71.9% to 73.4%]; P < .001], acute renal failure (77.6% [95% CI, 76.3% to 78.7%] vs 73.7% [95% CI, 72.2% to 75.0%]; P < .001), reoperation (63.7% [95% CI, 62.7% to 64.8%] vs 62.6% [95% CI, 61.5% to 63.7%]; P = .01), and the composite of mortality or major morbidity (70.3% [95% CI, 69.6% to 70.9%] vs 69.0% [95% CI, 68.3% to 69.7%]; P < .001). For 2 outcomes the c-index was comparable: stroke (68.4% [95% CI, 66.6% to 70.3%] vs 67.6% [95% CI, 65.7% to 69.5%]; P .08) and deep sternal wound infection (59.9% [95% CI, 53.6% to 66.2%] vs 64.1% [95% CI, 57.5% to 70.1%]; P = .82). CONCLUSIONS: The ML algorithm XGBoost demonstrated excellent calibration and modest improvements in discriminatory ability compared with existing STS models in this study of isolated SAVR.

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.

The train has left: Can surgeons still get a ticket to treat structural heart disease?

With the disruptive advancement of catheter-based technologies and minimally invasive techniques in structural heart disease, surgeons must obtain necessary skills to continue to serve this large patient population. We believe that surgeons are uniquely positioned to offer the full spectrum of therapy in structural heart disease (transcatheter, minimally invasive, and complex redo interventions), making them comprehensive valve specialists. Given the variability in structural heart training, we urgently recommend the establishment of a standardized curriculum and pathways for surgical trainees to gain proficiency in transcatheter technologies.

The state of transcatheter aortic valve implantation training in Canadian cardiac surgery residency programs.

BACKGROUND: The current state of transcatheter aortic valve implantation (TAVI) training for Canadian cardiac surgical residents is unknown. Our goals were to establish a national inventory of TAVI educational resources, elucidate the role of residents in TAVI programs, and determine the attitudes and perspectives of residents and program directors regarding the importance of TAVI technology and training. METHODS: We sent Web-based surveys and reminders to all Canadian cardiac surgical residents and program directors between February and July 2017. We used descriptive analyses to summarize data in an aggregate and anonymous manner. We analyzed patterned responses to open-ended survey questions using thematic analysis. RESULTS: Seventy-eight of 92 residents (85%) and 11 of 12 program directors (92%) completed the survey, with broad representation from across Canada. A minority of residents (14 [18%]) and program directors (4 [36%]) reported that TAVI training in their program was adequate. Only 3 program directors (27%) reported that their residents had access to TAVI simulation training. Although most residents (76 [97%]) and program directors (10 [91%]) agreed that TAVI was important to the trainee's future practice, about two-thirds (54 [69%] and 7 [64%], respectively) agreed that TAVI should be a focus of fellowship training. A perceived lack of interest from interventional cardiologists to teach surgical residents, competition from TAVI fellows and lack of formalized time during residency were identified as perceived barriers to TAVI training. CONCLUSION: As Canadian surgical residency training moves toward a Competence by Design curriculum, there remains a pressing need to create uniform learning objectives and expectations in the TAVI curriculum.

CONTEXTE: On ne connaît pas l'état actuel de la formation en implantation transcathéter de valvule aortique (ITVA) que reçoivent les médecins résidents dans les programmes canadiens de chirurgie cardiaque. Nous voulions dresser un inventaire national des ressources pédagogiques en ITVA, expliquer le rôle des médecins résidents dans les programmes d'ITVA et déterminer les attitudes et les points de vue des résidents et des directeurs de programme quant à l'importance de la technologie d'ITVA et de la formation en la matière. MÉTHODES: Entre février et juillet 2017, nous avons envoyé des sondages web et des rappels à tous les médecins résidents en chirurgie cardiaque et aux directeurs de ces programmes au Canada. Nous avons utilisé des analyses descriptives pour résumer les données de façon agrégée et anonyme. Nous avons analysé les réponses à des questions ouvertes et dégagé des tendances au moyen d'une analyse thématique. RÉSULTATS: Soixante-dix-huit des 92 résidents (85 %) et 11 des 12 directeurs de programme (92 %) ont répondu au sondage, avec une vaste représentation de partout au Canada. Une minorité de résidents (14 [18 %]) et de directeurs de programme (4 [36 %]) ont déclaré que la formation en ITVA offerte par leur programme était adéquate. Seuls 3 directeurs de programme (27 %) ont déclaré que leurs résidents avaient accès à une formation en simulation de l'ITVA. Bien que la plupart des résidents (76 [97 %]) et des directeurs de programme (10 [91 %]) soient d'accord pour dire que l'ITVA est importante pour la pratique future du stagiaire, environ les deux tiers (54 [69 %] et 7 [64 %], respectivement) sont d'avis que la formation à l'ITVA devrait faire l'objet d'un stage particulier. Un manque perçu d'intérêt de la part des cardiologues interventionnels pour l'enseignement aux médecins résidents en chirurgie, la compétition entre les stagiaires pour la formation à l'ITVA et le manque de temps officiellement réservé à ce volet pendant la résidence ont été identifiés comme des obstacles perçus à la formation en ITVA. CONCLUSION: À mesure que les programmes de résidence en chirurgie au Canada s'orientent vers une formation axée sur les compétences par conception, il demeure urgent de formuler des objectifs et des attentes d'apprentissage uniformes pour la formation en ITVA.

New methods and techniques in interventional cardiology. Evaluation the knowledge of medical students of Jagiellonian University Medical College.

INTRODUCTION: Interventional cardiology (IC) is a rapidly expanding field of medicine. Medical studies should provide students the necessary level of knowledge about new techniques in IC. The aim of the study was to assess the medical students' knowledge about various new areas of IC. MATERIAL AND METHODS: Self-designed questionnaire was used to assess student's knowledge. It contained 31 questions. The initial 3 questions concerned general information, the remaining ones were related to different IC techniques: Transcatheter Aortic Valve Implantation (TAVI), Bioresorbable Vascular Scaffold (BVS), percutaneous mitral regurgitation repair methods, Left Atrial Appendage Occlusion (LAAO), Renal DeNervation (RDN), Balloon Aortic Valvuloplasty (BAV) and Atrial Septal Defect/Persistent Foramen Ovale (ASD/PFO). One point for each correct answer was awarded. RESULTS: In our study participated 104 students. Mean score was 15.9 ± 5.8 points. 24% of participants were 3rd year students, 38% - 4th, 20% - 5th and 18% - 6th. There was no differences in level of knowledge between students of different years of studies (p = 0.2). Students from Students Research Groups (SRG) achieved higher score in comparison with students no attending SRG (19.3 ± 6.3 vs 13.3 ± 3.7; p <0.001) as well as students interested in cardiology comparison with other (19.6 ± 5.9 vs 13.0 ± 3.8; p <0.001). Students from SRG and interested in cardiology reached also higher results in practically every area of IC in comparison with other. CONCLUSIONS: Participants have insufficient, outdated and incomplete knowledge of new methods in IC. There was no significant difference in students of different years of studies. Students belonging to cardiological SRG and interested in cardiology have greater knowledge in IC.

Realistic Vascular Replicator for TAVR Procedures.

Transcatheter aortic valve replacement (TAVR) is an over-the-wire procedure for treatment of severe aortic stenosis (AS). TAVR valves are conventionally tested using simplified left heart simulators (LHS). While those provide baseline performance reliably, their aortic root geometries are far from the anatomical in situ configuration, often overestimating the valves' performance. We report on a novel benchtop patient-specific arterial replicator designed for testing TAVR and training interventional cardiologists in the procedure. The Replicator is an accurate model of the human upper body vasculature for training physicians in percutaneous interventions. It comprises of fully-automated Windkessel mechanism to recreate physiological flow conditions. Calcified aortic valve models were fabricated and incorporated into the Replicator, then tested for performing TAVR procedure by an experienced cardiologist using the Inovare valve. EOA, pressures, and angiograms were monitored pre- and post-TAVR. A St. Jude mechanical valve was tested as a reference that is less affected by the AS anatomy. Results in the Replicator of both valves were compared to the performance in a commercial ISO-compliant LHS. The AS anatomy in the Replicator resulted in a significant decrease of the TAVR valve performance relative to the simplified LHS, with EOA and transvalvular pressures comparable to clinical data. Minor change was seen in the mechanical valve performance. The Replicator showed to be an effective platform for TAVR testing. Unlike a simplified geometric anatomy LHS, it conservatively provides clinically-relevant outcomes and complement it. The Replicator can be most valuable for testing new valves under challenging patient anatomies, physicians training, and procedural planning.

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.

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.

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.

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

OBJECTIVES: Introduction of hybrid techniques, such as transapical transcatheter aortic valve replacement (TA-TAVR), requires skills that a heart team must master to achieve technical efficiency: the technical performance learning curve. To date, the learning curve for TA-TAVR remains unknown. We therefore evaluated the rate at which technical performance improved, assessed change in occurrence of adverse events in relation to technical performance, and determined whether adverse events after TA-TAVR were linked to acquiring technical performance efficiency (the learning curve). METHODS: From April 2007 to February 2012, 1100 patients, average age 85.0 ± 6.4 years, underwent TA-TAVR in the PARTNER-I trial. Learning curves were defined by institution-specific patient sequence number using nonlinear mixed modeling. RESULTS: Mean procedure time decreased from 131 to 116 minutes within 30 cases (P = .06) and device success increased to 90% by case 45 (P = .0007). Within 30 days, 354 patients experienced a major adverse event (stroke in 29, death in 96), with possibly decreased complications over time (P âˆ¼ .08). Although longer procedure time was associated with more adverse events (P < .0001), these events were associated with change in patient risk profile, not the technical performance learning curve (P = .8). CONCLUSIONS: The learning curve for TA-TAVR was 30 to 45 procedures performed, and technical efficiency was achieved without compromising patient safety. Although fewer patients are now undergoing TAVR via nontransfemoral access, understanding TA-TAVR learning curves and their relationship with outcomes is important as the field moves toward next-generation devices, such as those to replace the mitral valve, delivered via the left ventricular apex.

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

OBJECTIVES: To assess technical performance learning curves of teams performing transfemoral transcatheter aortic valve replacement (TF-TAVR). BACKGROUND: TF-TAVR is a new procedure for treating severe aortic stenosis. The number of cases required for procedural efficiency is unknown. METHODS: In the PARTNER-I trial, 1,521 patients underwent TF-TAVR from 4/2007-2/2012. Learning curve analysis of technical performance metrics was performed using institution-specific patient sequence number, interval between procedures, and institutional trial entry date. Learning curve characteristics were assessed using semi-parametric and parametric mixed-effects models. RESULTS: As patient sequence number increased, average procedure time decreased from 154 to 85 minutes (P < 0.0001), and fluoroscopy time from 28 to 20 minutes (P < 0.0001). Procedure time plateaued at an average of 83 minutes (range 52-140). Procedure time plateau was dynamic during the course of the trial, averaging 25 cases (range 21-52) by its end. The later institutions enrolled in the trial, the shorter the initial procedure time. During the trial, percutaneous rather than surgical access increased from 7.9% to 69%. CONCLUSIONS: Technical performance learning curves exist for TF-TAVR; procedural efficiency increased with experience, with concomitant decreases in radiation and contrast media exposure. The number of cases needed to achieve efficiency decreased progressively, with optimal procedural performance reached after approximately 25 cases for late-entering institutions. Knowledge and experience accumulated by early TF-TAVR institutions were disseminated, shortening the learning curve of late-entering institutions. Technological advances resulting from learning during the trial moved the field from initial conservative surgical cut-down to percutaneous access for most patients. © 2015 Wiley Periodicals, Inc.

Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: Success and safety.

OBJECTIVES: To identify number of cases needed to maximize device success and minimize adverse events after transfemoral transcatheter aortic valve replacement (TF-TAVR), and determine if adverse events were linked to the technical performance learning curve. BACKGROUND: TF-TAVR is a complex procedure with an incompletely characterized learning curve for clinical outcomes. METHODS: From 4/2007-2/2012, 1521 patients underwent TF-TAVR in the PARTNER-I trial. Outcomes learning curves were defined as number of cases needed to reach a plateau for device success, adverse events, and post-procedure length of stay. Institutional variation was accounted for by mixed-model non-linear techniques, which were also used to identify contribution of the procedure time learning curve to 30-day major adverse events and length of stay. RESULTS: Eighty percent device success was achieved after 22 cases; major vascular complications fell below 5% after 70 cases and major bleeding below 10% after 25 cases. It took an average of 28 cases to achieve a consistent low risk of 30-day major adverse events, but institutions entering in the middle of the trial achieved it after about 26. The most significant correlate of 30-day major adverse events and post-procedure length of stay was procedure time (P < 0.0001). However, this association was related to patient and unmeasured variables, not the procedure time learning curve (P = 0.6). CONCLUSIONS: By end of trial, a consistent low risk of adverse events was achieved after ∼26 cases. However, these improved results were due to change in patient risk profile; outcomes were not linked to the technical performance learning curve. © 2015 Wiley Periodicals, Inc.