Transapical aortic valve replacement for severe aortic stenosis: results from the nonrandomized continued access cohort of the PARTNER trial

Shockwave and Non-transfemoral Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has become a widely adopted treatment modality for severe aortic stenosis. Transfemoral access is the approach of choice; however, approximately 25% of patients undergoing TAVR also have concomitant peripheral arterial disease. The recent advent of intravascular lithotripsy has enabled preservation of transfemoral access in some patients; although, a proportion still require alternative, non-femoral access. Alternative access sites can be broadly categorized into transthoracic and peripheral, facilitated by surgical or percutaneous techniques. In this review, the technical details and clinical outcomes of various TAVR accesses are discussed. Initially, transthoracic approaches were most common, but recently, the trend has been toward alternative peripheral access due to superior outcomes. Although there are no randomized data to support all the alternative access sites, the experiences reported provide available options for a large portion of patients to be candidates for TAVR. The intervention site should be selected by a multidisciplinary heart team based on patient anatomical factors and institutional expertise.

Trans-Iliac Aortic Valve Replacement: Feasibility, Safety, and Medium-Term Follow-up

Background

Transcatheter aortic valve replacement (TAVR) is nowadays generally accepted as the treatment of choice for high- to intermediate-risk patients with severe aortic stenosis not suitable for the standard surgical replacement. Many vascular accesses have been described for the valve delivery, comprising the common iliac artery as the arterial site of access.

Methods

From September 2008 to June 2014, 440 patients underwent TAVR at our institution. We report a series of 12 patients that have undergone TAVR via a trans-iliac (TI) retroperitoneal surgical approach and also discuss its feasibility, security, and medium-term follow-up.

Results

The 30-day survival rate was 92%. Only 1 local vascular access major complication occurred requiring an iliac-femoral bypass grafting with a vascular graft. Two patients experienced transient neurological ischemic attack. At 3-year follow-up, all the 11 patients were alive and well and the echocardiographic evaluation revealed good function of the prosthesis.

Conclusions

The TI route seems to be feasible with a low profile of local complications. It may be a reasonable access alternative to the femoral artery and to the trans-apical approach. A broader, prospective study is advisable to gain general consensus on this approach.

Longitudinal Hemodynamics of Transcatheter and Surgical Aortic Valves in the PARTNER Trial

Importance

Use of transcatheter aortic valve replacement (TAVR) for severe aortic stenosis is growing rapidly. However, to our knowledge, the durability of these prostheses is incompletely defined.

Objective

To determine the midterm hemodynamic performance of balloon-expandable transcatheter heart valves.

Design, Setting, and Participants

In this study, we analyzed core laboratory-generated data from echocardiograms of all patients enrolled in the Placement of Aortic Transcatheter Valves (PARTNER) 1 Trial with successful TAVR or surgical AVR (SAVR) obtained preimplantation and at 7 days, 1 and 6 months, and 1, 2, 3, 4, and 5 years postimplantation. Patients from continued access observational studies were included for comparison.

Interventions

Successful implantation after randomization to TAVR vs SAVR (PARTNER 1A; TAVR, n = 321; SAVR, n = 313), TAVR vs medical treatment (PARTNER 1B; TAVR, n = 165), and continued access (TAVR, n = 1996). Five-year echocardiogram data were available for 424 patients after TAVR and 49 after SAVR.

Main Outcomes and Measures

Death or reintervention for aortic valve structural indications, measured using aortic valve mean gradient, effective orifice area, Doppler velocity index, and evidence of hemodynamic deterioration by reintervention, adverse hemodynamics, or transvalvular regurgitation.

Results

Of 2795 included patients, the mean (SD) age was 84.5 (7.1) years, and 1313 (47.0%) were female. Population hemodynamic trends derived from nonlinear mixed-effects models showed small early favorable changes in the first few months post-TAVR, with a decrease of -2.9 mm Hg in aortic valve mean gradient, an increase of 0.028 in Doppler velocity index, and an increase of 0.09 cm2 in effective orifice area. There was relative stability at a median follow-up of 3.1 (maximum, 5) years. Moderate/severe transvalvular regurgitation was noted in 89 patients (3.7%) after TAVR and increased over time. Patients with SAVR showed no significant changes. In TAVR, death/reintervention was associated with lower ejection fraction, stroke volume index, and aortic valve mean gradient up to 3 years, with no association with Doppler velocity index or valve area. Reintervention occurred in 20 patients (0.8%) after TAVR and in 1 (0.3%) after SAVR and became less frequent over time. Reintervention was caused by structural deterioration of transcatheter heart valves in only 5 patients. Severely abnormal hemodynamics on echocardiograms were also infrequent and not associated with excess death or reintervention for either TAVR or SAVR.

Conclusions and Relevance

This large, core laboratory-based study of transcatheter heart valves revealed excellent durability of the transcatheter heart valves and SAVR. Abnormal findings in individual patients, suggestive of valve thrombosis or structural deterioration, were rare in this protocol-driven database and require further investigation.

Trial Registration

clinicaltrials.gov Identifier: NCT00530894.

Access Sites for TAVI: Patient Selection Criteria, Technical Aspects, and Outcomes

During the last ten years, transcatheter aortic valve implantation (TAVI) has become a reliable and valid alternative treatment for elderly patients with severe symptomatic aortic valve stenosis requiring valve replacement and being at high or intermediate surgical risk. While common femoral arteries are the access site of choice in the vast majority of TAVI patients, in up to 15–20% of TAVI candidates this route might be precluded due to the presence of diffuse atherosclerotic disease, tortuosity or small vessel diameter. Therefore, in order to achieve an antegrade or retrograde implant, several alterative access routes have been described, namely trans-axillary, trans-aortic, trans-apical, trans-carotid, trans-septal, and trans-caval. The aim of this paper is to give a concise overview on vascular access sites for TAVI, with a particular focus on patient's selection criteria, imaging, technical aspects, and clinical outcome.

A Review of Alternative Access for Transcatheter Aortic Valve Replacement

With the advent of transcatheter aortic valve replacement (TAVR), appropriately selected intermediate-, high-, and extreme-risk patients with severe aortic stenosis (AS) are now offered a less invasive option compared to conventional surgery. In contemporary practice, TAVR is performed predominantly via a transfemoral arterial approach, whereby a transcatheter heart valve (THV) is delivered in a retrograde fashion through the iliofemoral arterial system and thoraco-abdominal aorta, into the native aortic valve annulus. While the majority of patients possess suitable anatomy for transfemoral arterial access, there is a subset of patients with extensive peripheral vascular disease that precludes this traditional approach to TAVR. Fortunately, innovation in the field of structural heart disease has led to the refinement of alternative access options for THV delivery. Selection of the most appropriate route of therapy mandates a careful consideration of multiple factors, including patient anatomy, technical feasibility, and equipment specifications. Furthermore, understanding the risks conferred by each access site for valve delivery-notably stroke, vascular injury, and major bleeding-is of paramount importance when selecting the approach that will best optimize the outcome for an individual. In this review, we provide a comprehensive summary of alternative approaches to transfemoral arterial TAVR as well as the available outcome data supporting each of these various techniques.

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.

Insight into the inhibitor discrimination by FLT3 F691L

Fms-like tyrosine kinase 3 (FLT3) belongs to the receptor tyrosine kinase family and expressed in hematopoietic progenitor cells. FLT3 gene mutations are reported in ~30% of acute myeloid leukemia cases. FLT3 kinase domain mutation F691L is one of the common causes of acquired resistance to the FLT3 inhibitors including quizartinib. MZH29 and crenolanib were previously reported to inhibit FLT3 F691L. However, crenolanib was reported for the moderate inhibition. We found that Glu661and Asp829 were the most significant residues to target the FLT3 F691L which contribute most significantly to the binding energy with MZH29 and crenolanib. These interactions were found absent with quizartinib. Further free energy landscape analysis revealed that FLT3 F691L bound to MZH29 and crenolanib was more stable as compared to quizartinib.

Transapical cardioscopic mitral annuloplasty: a short-term survival study in a porcine model

OBJECTIVES

The transapical approach provides concurrent surgical access to the mitral and the aortic valves, the root of the aorta and the left atrium. We previously showed the feasibility of transapical cardioscopic (TAC) surgery in a non-survival porcine model. However, reproducibility and feasibility of ring implantation using TAC have not been reported. Therefore, in this study, we hypothesized that implantation of a mitral annuloplasty ring can be feasibly and safely carried out endoscopically via the apex of the heart.

METHODS

Using a porcine model in a short-term survival study, TAC mitral annuloplasty was performed in 6 pigs via an incision over the xyphoid, under cardiopulmonary bypass and cardiac arrest. A mitral annuloplasty ring was implanted via the apex to a normal mitral annulus, using a customized set of instruments and techniques. Haemodynamics, echocardiography, cardiac computed tomography, ventriculography, electrocardiography and histopathology studies were used to evaluate the function of the mitral valve and the left ventricle, coronary system and conduction system in the perioperative period and 4 weeks later.

RESULTS

All 6 animals survived and recovered from the TAC annuloplasty procedure. Postimplantation examination showed that the mitral valve was competent, left ventricular ejection fraction was 63 ± 4%, left ventricular length was 6.2 ± 0.5 cm and left ventricular end-diastolic volume was 80 ± 10 ml, which were comparable to preoperative values. Apart from a dense scar at the apex, no significant injury was noticed on the ventricle, the chordae and the mitral leaflets. The bypass, cross-clamp and implantation times were 181 ± 55 min, 130 ± 37 min and 47 ± 6 min, respectively.

CONCLUSIONS

Despite long surgical times due to the initial learning curve, successful execution of mitral ring annuloplasty could be safely achieved using the TAC approach, via a small incision without the involvement of sternum or the right pleural cavity, thereby potentially expanding the indication to patients with high-risk full sternotomy or right thoracotomy.

Early and mid-term outcomes after transcatheter aortic valve implantation (TAVI) in Ireland

BACKGROUND

TAVI is a percutaneous approach to aortic valve replacement in high surgical risk patients deemed inoperable.

AIM

To evaluate the early and mid-term outcomes for an Irish TAVI cohort over a six-year period at St James's Hospital and Blackrock Clinic, Dublin, Ireland.

RESULTS

In total 147 patients, 56% male with an average age of 82 underwent TAVI between December 2008 and December 2014. Thirty day, one year and two year survival was 90.5%, 83% and 71% respectively. Major vascular complications and renal failure were the biggest predictors of mortality at 30 days (p = 0.02). We observed a pacing rate of 13.5%, the majority in patients who had Medtronic Corevalve implants (p < 0.05). With increasing procedural experience there was a reduction in length of stay from 10 days to 7.5 days.

CONCLUSION

This review, the first of its kind in Ireland showed favorable rates of 30 day and one year and two year survival post TAVI with procedural success and complication rates similar to international registry data.

Patient selection for transcatheter aortic valve replacement: A combined clinical and multimodality imaging approach

Transcatheter aortic valve replacement (TAVR) has been validated as a new therapy for patients affected by severe symptomatic aortic stenosis who are not eligible for surgical intervention because of major contraindication or high operative risk. Patient selection for TAVR should be based not only on accurate assessment of aortic stenosis morphology, but also on several clinical and functional data. Multi-Imaging modalities should be preferred for assessing the anatomy and the dimensions of the aortic valve and annulus before TAVR. Ultrasounds represent the first line tool in evaluation of this patients giving detailed anatomic description of aortic valve complex and allowing estimating with enough reliability the hemodynamic entity of valvular stenosis. Angiography should be used to assess coronary involvement and plan a revascularization strategy before the implant. Multislice computed tomography play a central role as it can give anatomical details in order to choice the best fitting prosthesis, evaluate the morphology of the access path and detect other relevant comorbidities. Cardiovascular magnetic resonance and positron emission tomography are emergent modality helpful in aortic stenosis evaluation. The aim of this review is to give an overview on TAVR clinical and technical aspects essential for adequate selection.

One-Year Outcomes of Transcatheter Aortic Valve Implantation Using the Direct Aortic Approach

BACKGROUND

The direct aortic (DA) approach allows for transcatheter aortic valve implantation (TAVI) in patients with difficult peripheral vascular anatomy. The CoreValve ADVANCE Direct Aortic (ADVANCE DA) study was performed to assess the outcomes of DA TAVI with the CoreValve System (Medtronic, Minneapolis, MN) in routine practice.

METHODS

Patients were selected for the DA approach by local cardiac surgical teams, and TAVI was performed with patients under general anesthesia. Safety events were adjudicated according to the Valve Academic Research Consortium-2 definitions by an independent clinical events committee. All imaging data, including that from multislice computed tomography and follow-up echocardiography, were analyzed by an independent core laboratory.

RESULTS

From September 2012 to February 2014, 100 patients were enrolled (52.0% male, age 81.9 ± 5.9 years, The Society of Thoracic Surgeons Score 5.9 ± 3.2%) at 9 centers in Europe. Peripheral vascular disease was present in 51.0% of patients, and 38.0% had diabetes. Of the 100 patients enrolled, 92 underwent TAVI. At 30 days after TAVI, 98.1% were free of moderate or severe paravalvular leak. At 1 year, 16 patients had died (Kaplan-Meier rate 17.9%), 1 (1.1%) patient had had a stroke, classified as nondisabling, and 15 (17.0%) patients had received a permanent pacemaker. Most patients experienced improved quality of life as measured by the Kansas City Cardiomyopathy Questionnaire overall summary score (mean change from baseline to 1 year, 39.6 ± 26.3; p < 0.01).

CONCLUSIONS

The DA approach provides a feasible alternative for patients with challenging anatomic features that may otherwise preclude use of the TAVI procedure.

Insights Into Timing, Risk Factors, and Outcomes of Stroke and Transient Ischemic Attack After Transcatheter Aortic Valve Replacement in the PARTNER Trial (Placement of Aortic Transcatheter Valves)

Background—

Prior studies of stroke and transient ischemic attack (TIA) after transcatheter aortic valve replacement (TAVR) are limited by reporting and follow-up variability. This is a comprehensive analysis of time-related incidence, risk factors, and outcomes of these events.

Methods and Results—

From April 2007 to February 2012, 2621 patients, aged 84±7.2 years, underwent transfemoral (TF; 1521) or transapical (TA; 1100) TAVR in the PARTNER trial (Placement of Aortic Transcatheter Valves; as-treated), including the continued access registry. Stroke and TIA were identified by protocol and adjudicated by a Clinical Events Committee. Within 30 days of TAVR, 87 (3.3%) patients experienced a stroke (TF 58 [3.8%]; TA 29 [2.7%]; P =0.09), 85% within 1 week. Instantaneous stroke risk peaked on day 2, then fell to a low prolonged risk of 0.8% by 1 to 2 weeks. Within 30 days, 13 (0.50%) patients experienced a TIA (TF 10 [0.67%]; TA 3 [0.27%]; P >0.17). Stroke and TIA were associated with lower 1-year survival than expected (TF 47% after stroke versus 82%, and 64% after TIA versus 83%; TA 53% after stroke versus 80%, and 64% after TIA versus 83%). Risk factors for early stroke after TA-TAVR included more postdilatations, pure aortic stenosis without regurgitation, and possibly more pacing runs, earlier date of procedure, and no dual antiplatelet therapy; high pre-TAVR aortic peak gradient was a risk factor for stroke early after TF-TAVR.

Conclusions—

Risk of stroke or TIA is highest early after TAVR and is associated with increased 1-year mortality. Modifications of TAVR, emboli-prevention devices, and better intraprocedural pharmacological protection may mitigate this risk.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00530894.

Transaortic transcatheter aortic valve replacement through a right minithoracotomy with the balloon-expandable Sapien 3 valve

Transaortic transcatheter aortic valve replacement performed through a right anterolateral minithoracotomy at the second intercostal space is a safe and standardized minimally invasive procedure carrying important clinical advantages for the patient, in particular, no damage to the ventricular apex, preservation of the diseased peripheral arteries and no cross of the aortic arch with the delivery system, meaning a lower risk of calcium dislodgement and neurological complications. Using the third-generation, balloon-expandable Edwards Sapien™ 3 transcatheter heart valve and the Certitude™ delivery system, the transaortic procedure is easily performed under fluoroscopic and echocardiographic guidance. Compared with the transapical procedure, the transaortic technique requires an inversely mounted stent valve and follows the standard guidelines for valve positioning and deployment under rapid pacing. The transaortic approach through a right anterolateral minithoracotomy at the second intercostal space combines the positive aspects of both transfemoral and transapical valve replacements without the risks of either procedure (left ventricular, coronary and peripheral vascular injuries).

Results of surgical aortic valve replacement and transapical transcatheter aortic valve replacement in patients with previous coronary artery bypass grafting

OBJECTIVES

To evaluate the results of aortic valve replacement through sternotomic approach in redo scenarios (RAVR) vs transapical transcatheter aortic valve replacement (TAVR), in patients in the eighth decade of life or older already undergone previous coronary artery bypass grafting (CABG).

METHODS

One hundred and twenty-six patients undergoing RAVR were compared with 113 patients undergoing TaTAVR in terms of 30-day mortality and Valve Academic Research Consortium-2 outcomes. The two groups were also analysed after propensity-matching.

RESULTS

TaTAVR patients demonstrated a higher incidence of 30-day mortality (P = 0.03), stroke (P = 0.04), major bleeding (P = 0.03), worse 'early safety' (P = 0.04) and lower permanent pacemaker implantation (P = 0.03). TaTAVR had higher follow-up hazard in all-cause mortality [hazard ratio (HR) 3.15, 95% confidence interval (CI) 1.28-6.62; P < 0.01] and cardiovascular mortality (HR 1.66, 95% CI 1.02-4.88; P = 0.04). Propensity-matched patients showed comparable 30-day outcome in terms of survival, major morbidity and early safety, with only a lower incidence of transfusions after TaTAVR (10.7% vs RAVR: 57.1%; P < 0.01). A trend towards lower Acute Kidney Injury Network Classification 2/3 (3.6% vs RAVR 21.4%; P = 0.05) and towards a lower freedom from all-cause mortality at follow-up (TaTAVR: 44.3 ± 21.3% vs RAVR: 86.6 ± 9.3%; P = .08) was demonstrated after TaTAVR, although cardiovascular mortality was comparable (TaTAVR: 86.5 ± 9.7% vs RAVR: 95.2 ± 4.6%; P = 0.52). Follow-up freedom from stroke, acute heart failure, reintervention on AVR and thrombo-embolisms were comparable (P = NS). EuroSCORE II (P = 0.02), perioperative stroke (P = 0.01) and length of hospitalization (P = 0.02) were the determinants of all-cause mortality at follow-up, whereas perioperative stroke (P = 0.03) and length of hospitalization (P = 0.04) impacted cardiovascular mortality at follow-up.

CONCLUSIONS

Reported differences in mortality and morbidity after TaTAVR and RAVR reflect differences in baseline risk profiles. Given the lower trend for renal complications, patients at higher perioperative renal risk might be better served by TaTAVR.

Association Between Transcatheter Aortic Valve Implantation Volume and Outcomes in the United States

With the rapid advance of transcatheter aortic valve implantation (TAVI), it is important to evaluate the relationship between TAVI volumes and outcomes. The aim of this study was to analyze in-hospital outcomes after TAVI stratified according to hospital volumes. Using the National Inpatient Sample files from 2012, hospitals performing transfemoral (TF)-TAVI and transapical (TA)-TAVI were divided into high-volume and low-volume centers. A total of 7,660 patients underwent TAVI in 256 hospitals in 2012. In the TF-TAVI cohort, multivariate logistic regression analyses demonstrated that low TF-TAVI volume status was an independent predictor of death and bleeding. In the TA-TAVI cohort, low volume status was a predictor of death, myocardial infarction, and need for permanent pacemaker. In addition, hospitals that performed low TA-TAVI volume were associated with significantly higher rate of death after surgical aortic valve replacement in comparison with the hospitals that perform high TA-TAVI volume (3.6% vs 2.3%, p <0.001). In conclusion, centers with lower volume of TAVI had more frequent adverse events compared with higher volume centers.

Access and closure of the left ventricular apex: state of play

Calcific aortic stenosis is the most frequent manifestation of valvular heart disease. The preferred treatment for patients of all age groups is surgical aortic valve replacement. Recently, transcatheter aortic valve implantation (TAVI) has become the standard of care for patients that are deemed to be at high risk for open heart surgery. The most common access route for TAVI is the retrograde transfemoral (TF) approach, followed by the antegrade transapical (TA) approach. Both access routes have distinct indications. While the TF route is least invasive and the access of choice at most centers, the apical route is used complementary in patients with poor femoral access. In addition, the TA approach holds various benefits such as a short distance from the operator to the annulus facilitating exact positioning of the valve and the possibility to accommodate larger sheaths. Furthermore, the TA approach not only provides direct access to the aortic valve but also the mitral valve allowing for a wide range of interventions. Various apical closure devices are currently being developed under the premise of increasing overall safety of the TA-TAVI approach by further standardizing the procedure, alleviating left ventricular access and minimizing the risk of complications, such as apical bleeding. The aim of this article is to give an overview of current devices for apical closure. The ideal apical closure device should be easy to put in place, leave a minimum of foreign material, provide complete hemostasis and have a minimal risk of displacement. So far the range of commercially available devices in Europe is very limited with only one CE-certified device on the market and one device that is expected to receive CE-certification soon. Off-the-shelf closure devices could help flatten the initial operator learning curve and facilitate a safe apical access, ultimately leading to an entirely percutaneous TA-TAVI approach.

The Anesthetic Management of Transcatheter Aortic Valve Implantation

An increasing number of patients with a high risk for surgery because of advanced age and associated comorbidities that significantly increase the perioperative risk successfully undergo transcatheter aortic valve implantation (TAVI). TAVI is commonly performed under general or local anesthesia or local anesthesia plus mild sedation to achieve a conscious sedation. The anesthetic regimen generally depends on the patient’s clinical profile and the procedural technical characteristics, but the center’s experience and internal organization likely play an important role in anesthetic decision making. The large variation in anesthetic management among various centers and countries likely depends on the different composition of the operating team and institutional organization. Therefore, a tight interaction among the various members of the TAVI team, including the cardiac anesthetist, provides the proper anesthetic management using the chosen procedural technique.

Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality.

METHODS

Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed.

RESULTS

Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity.

CONCLUSION

Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial

BACKGROUND

The Placement of Aortic Transcatheter Valves (PARTNER) trial showed that mortality at 1 year, 2 years, and 3 years is much the same with transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) for high-risk patients with aortic stenosis. We report here the 5-year outcomes.

METHODS

We did this randomised controlled trial at 25 hospitals, in Canada (two), Germany (one), and the USA (23). We used a computer-generated randomisation sequence to randomly assign high-risk patients with severe aortic stenosis to either SAVR or TAVR with a balloon-expandable bovine pericardial tissue valve by either a transfemoral or transapical approach. Patients and their treating physicians were not masked to treatment allocation. The primary outcome of the trial was all-cause mortality in the intention-to-treat population at 1 year, we present here predefined outcomes at 5 years. The study is registered with ClinicalTrials.gov, number NCT00530894.

FINDINGS

We screened 3105 patients, of whom 699 were enrolled (348 assigned to TAVR, 351 assigned to SAVR). Overall mean Society of Thoracic Surgeons Predicted Risk of Mortality score was 11·7%. At 5 years, risk of death was 67·8% in the TAVR group compared with 62·4% in the SAVR group (hazard ratio 1·04, 95% CI 0·86-1·24; p=0·76). We recorded no structural valve deterioration requiring surgical valve replacement in either group. Moderate or severe aortic regurgitation occurred in 40 (14%) of 280 patients in the TAVR group and two (1%) of 228 in the SAVR group (p<0·0001), and was associated with increased 5-year risk of mortality in the TAVR group (72·4% for moderate or severe aortic regurgitation vs 56·6% for those with mild aortic regurgitation or less; p=0·003).

INTERPRETATION

Our findings show that TAVR as an alternative to surgery for patients with high surgical risk results in similar clinical outcomes.

FUNDING

Edwards Lifesciences.

Temporal Trends in Quality of Life Outcomes After Transapical Transcatheter Aortic Valve Replacement: A Placement of AoRTic TraNscathetER Valve (PARTNER) Trial Substudy

BACKGROUND

In the Placement of AoRTic TraNscathetER Valve (PARTNER) randomized controlled trial (RCT), which represented the first exposure to transapical transcatheter aortic valve replacement (TA-TAVR) for many clinical sites, high-risk patients undergoing TA-TAVR derived similar health-related quality of life (HRQoL) outcomes when compared with surgical aortic valve replacement (SAVR). With increasing experience, it is possible that HRQoL outcomes of TA-TAVR may have improved.

METHODS AND RESULTS

We evaluated HRQoL outcomes at 1-, 6-, and 12-month follow-ups among 875 patients undergoing TA-TAVR in the PARTNER nonrandomized continued access (NRCA) registry and compared these outcomes with those of the TA-TAVR and SAVR patients in the PARTNER RCT. HRQoL was assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ), the Medical Outcomes Study Short-Form 12, and the EuroQoL-5D, with the KCCQ overall summary score serving as the primary end point. The NRCA TA-TAVR and RCT TA-TAVR and SAVR groups were generally similar. The primary outcome, the KCCQ summary score, did not differ between the NRCA TA-TAVR and the RCT TA-TAVR group at any follow-up timepoints, although there were small differences in favor of the NRCA cohort on several KCCQ subscales at 1 month. There were no significant differences in follow-up HRQOL between the NRCA-TAVR and the RCT SAVR cohorts on the KCCQ overall summary scale or any of the disease-specific or generic subscales.

CONCLUSIONS

Despite greater experience with TA-TAVR in the NRCA registry, HRQoL outcomes remained similar to those of TA-TAVR in the original RCT cohort and no better than those with SAVR. These findings have important implications for patient selection for TAVR when transfemoral access is not an option.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Propensity-Matched Comparisons of Clinical Outcomes After Transapical or Transfemoral Transcatheter Aortic Valve Replacement

Background—

The higher risk of adverse outcomes after transapical (TA) versus transfemoral (TF) transcatheter aortic valve replacement (TAVR) could be attributable to TA-TAVR being an open surgical procedure or to clinical differences between TA- and TF-TAVR patients. We compared outcomes after neutralizing patient differences using propensity score matching.

Methods and Results—

From April 2007 to February 2012, 1100 Placement of Aortic Transcatheter Valves (PARTNER)-I patients underwent TA-TAVR and 1521 underwent TF-TAVR with Edwards SAPIEN balloon-expandable bioprostheses. Propensity matching based on 111 preprocedural variables, exclusive of femoral access morphology, identified 501 well-matched patient pairs (46% of possible matches), 95% of whom had peripheral arterial disease. Matched TA-TAVR patients experienced more adverse procedural events, longer length of stay (5 versus 8 days; P <0.0001), and slower recovery (New York Heart Association class I, 31% versus 38% at 30 days, equalizing by 6 months at 51% versus 47%); stroke risk was similar (3.4% versus 3.3% at 30 days and 6.0% versus 6.7% at 3 years); mortality was elevated for the first 6 postprocedural months (19% versus 12%; P =0.01); but aortic regurgitation was less (34% versus 52% mild and 8.9% versus 12% moderate to severe at discharge, P =0.001; 36% versus 50% mild and 10% versus 15% moderate to severe at 6 months, P <0.0001).

Conclusions—

The likelihood of adverse periprocedural events and prolonged recovery is greater after TA-TAVR than TF-TAVR in vasculopathic patients after accounting for differences in cardiovascular risk factors, although stroke risk is equivalent and aortic regurgitation is less. As smaller delivery systems permit TF-TAVR in many of these patients, we recommend a TF-first access strategy for TAVR when anatomically feasible.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00530894.

Characterizing and Overriding the Structural Mechanism of the Quizartinib-Resistant FLT3 "Gatekeeper" F691L Mutation with PLX3397

Tyrosine kinase domain mutations are a common cause of acquired clinical resistance to tyrosine kinase inhibitors (TKI) used to treat cancer, including the FLT3 inhibitor quizartinib. Mutation of kinase "gatekeeper" residues, which control access to an allosteric pocket adjacent to the ATP-binding site, has been frequently implicated in TKI resistance. The molecular underpinnings of gatekeeper mutation-mediated resistance are incompletely understood. We report the first cocrystal structure of FLT3 with the TKI quizartinib, which demonstrates that quizartinib binding relies on essential edge-to-face aromatic interactions with the gatekeeper F691 residue, and F830 within the highly conserved Asp-Phe-Gly motif in the activation loop. This reliance makes quizartinib critically vulnerable to gatekeeper and activation loop substitutions while minimizing the impact of mutations elsewhere. Moreover, we identify PLX3397, a novel FLT3 inhibitor that retains activity against the F691L mutant due to a binding mode that depends less vitally on specific interactions with the gatekeeper position.

SIGNIFICANCE

We report the first cocrystal structure of FLT3 with a kinase inhibitor, elucidating the structural mechanism of resistance due to the gatekeeper F691L mutation. PLX3397 is a novel FLT3 inhibitor with in vitro activity against this mutation but is vulnerable to kinase domain mutations in the FLT3 activation loop.

Transcatheter aortic valve implantation

Transcatheter aortic valve implantation was developed to offer a therapeutic solution to patients with severe symptomatic aortic stenosis who are not candidates for conventional aortic valve replacement. The improvement in transcatheter aortic valve implantation outcomes is still of concern in the areas of stroke, vascular injury, heart block, paravalvular regurgitation and valve durability. Concomitantly, the progress, both technical and in terms of material advances of transcatheter valve systems, as well as in patient selection, renders transcatheter aortic valve implantation an increasingly viable treatment for more and more patients with structural heart disease.

Costs of periprocedural complications in patients treated with transcatheter aortic valve replacement: results from the Placement of Aortic Transcatheter Valve trial

BACKGROUND

In patients with severe aortic stenosis, transcatheter aortic valve replacement (TAVR) improves survival when compared with nonsurgical therapy but with higher in-hospital and lifetime costs. Complications associated with TAVR may decrease with greater experience and improved devices, thereby reducing the overall cost of the procedure. Therefore, we sought to estimate the effect of periprocedural complications on in-hospital costs and length of stay of TAVR.

METHODS AND RESULTS

Using detailed cost data from 406 TAVR patients enrolled in the Placement of Aortic Transcatheter Valve (PARTNER) I trial, we developed multivariable models to estimate the incremental cost and length of stay associated with specific periprocedural complications. Attributable costs and length of stay for each complication were calculated by multiplying the independent cost of each event by its frequency in the treatment group. Mean cost for the initial hospitalization was $79 619±40 570 ($50 891 excluding the valve); 49% of patients had ≥1 complication. Seven complications were independently associated with increased hospital costs, with major bleeding, arrhythmia, and death accounting for the largest attributable cost per patient. Renal failure and the need for repeat TAVR, although less frequent, were also associated with substantial incremental and attributable costs. Overall, complications accounted for $12 475 per patient in initial hospital costs and 2.4 days of hospitalization.

CONCLUSIONS

In the PARTNER trial, periprocedural complications were frequent, costly, and accounted for ≈25% of non-implant-related hospital costs. Avoidance of complications should improve the cost-effectiveness of TAVR for inoperable and high-risk patients, but reductions in the cost of uncomplicated TAVR will also be necessary for optimal efficiency.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Caval-aortic access to allow transcatheter aortic valve replacement in otherwise ineligible patients: initial human experience

OBJECTIVES

This study describes the first use of caval-aortic access and closure to enable transcatheter aortic valve replacement (TAVR) in patients who lacked other access options. Caval-aortic access refers to percutaneous entry into the abdominal aorta from the femoral vein through the adjoining inferior vena cava.

BACKGROUND

TAVR is attractive in high-risk or inoperable patients with severe aortic stenosis. Available transcatheter valves require large introducer sheaths, which are a risk for major vascular complications or preclude TAVR altogether. Caval-aortic access has been successful in animals.

METHODS

We performed a single-center retrospective review of procedural and 30-day outcomes of prohibitive-risk patients who underwent TAVR via caval-aortic access.

RESULTS

Between July 2013 and January 2014, 19 patients underwent TAVR via caval-aortic access; 79% were women. Caval-aortic access and tract closure were successful in all 19 patients; TAVR was successful in 17 patients. Six patients experienced modified VARC-2 major vascular complications, 2 (11%) of whom required intervention. Most (79%) required blood transfusion. There were no deaths attributable to caval-aortic access. Throughout the 111 (range 39 to 229) days of follow up, there were no post-discharge complications related to tract creation or closure. All patients had persistent aorto-caval flow immediately post-procedure. Of the 16 patients who underwent repeat imaging after the first week, 15 (94%) had complete closure of the residual aorto-caval tract.

CONCLUSIONS

Percutaneous transcaval venous access to the aorta allows TAVR in otherwise ineligible patients, and may offer a new access strategy for other applications requiring large transcatheter implants.

Transapical versus transfemoral aortic valve implantation: a multicenter collaborative study

BACKGROUND

There are no direct comparisons between transapical aortic valve implantation (TA-AVI) and transfemoral aortic valve implantation (TF-AVI). Therefore, the aim of this study was to compare the short-term and midterm outcomes of TA-AVI versus TF-AVI.

METHODS

Data from four European centers were pooled and analyzed. To minimize differences between TA-AVI and TF-AVI multivariable analysis was used. Study endpoints were defined according to the Valve Academic Research Consortium-I criteria at 30 days and 1 year. Primary endpoints of this study were 30-day all-cause mortality and mortality during follow-up.

RESULTS

A total of 882 patients underwent TAVI, of whom 793 (89.9%) underwent TF-AVI and 89 (10.1%) underwent TA-AVI. Patients undergoing TA-AVI had a higher estimated risk of mortality as defined by the logistic European System for Cardiac Operative Risk Evaluation score (median 27.0, interquartile range [IQR]: 20.2 to 33.8 versus median 20.0, IQR: 12.3 to 27.7; p < 0.001) and The Society of Thoracic Surgeons Score (median 10.2, IQR: 5.3 to 9.9 versus median 6.7, IQR: 3.5 to 9.9; p < 0.001) and had more comorbidities. At 30 days, there was an increased risk of all-cause mortality in the TA-AVI group (odds ratio [OR] 3.12, 95% confidence interval [CI]: 1.43 to 6.82; p = 0.004). TF-AVI was associated with a higher frequency of major (OR 0.33, 95% CI: 0.12 to 0.90; p = 0.031) and minor vascular complications (OR 0.17, 95% CI: 0.04 to 0.71; p = 0.0015). In-hospital stay was significantly longer among patients undergoing TA-AVI (OR 2.29, 95% CI: 1.28 to 4.09; p = 0.05). During a median follow-up of 365 days (IQR: 174 to 557), TA-AVI was associated with an increased risk of all-cause mortality (hazard ratio 1.88, 95% CI: 1.23 to 2.87; p = 0.004).

CONCLUSIONS

In institutions performing a low volume of TA-AVI, the technique is associated with an increased risk of all-cause mortality and longer hospital stay but less vascular complications in comparison with TF-AVI. The interaction between experience and type of treatment on outcome requires further investigation before advocating one treatment over the other.

Patient selection for transcatheter aortic valve implantation: An interventional cardiology perspective

Transcatheter aortic valve implantation (TAVI) has emerged as a highly effective minimally invasive treatment symptomatic for severe calcific aortic stenosis in patients at high or prohibitive surgical risk. The success of TAVI has been determined by a number of factors, but in particular by appropriate patient selection. Appropriate patient selection involves identifying patients with the potential to benefit most from TAVI and individualizing the bioprosthesis type and size, and the vascular access site for each case. We present herein, our critical appraisal on patient selection for TAVI: an interventional cardiology perspective.