United States Feasibility Study of Transcatheter Insertion of a Stented Aortic Valve by the Left Ventricular Apex

Transcatheter aortic valve replacement in patients with severe aortic stenosis who are at high risk for surgical complications: summary assessment of the California Technology Assessment Forum

BACKGROUND

The California Technology Assessment Forum is dedicated to assessment and public reporting of syntheses of available data on medical technologies. In this assessment, transcatheter aortic valve replacement (TAVR) was evaluated for patients with severe aortic stenosis (AS) who are at high risk for complications.

METHODS AND RESULTS

In this assessment, 5 criteria were used: Regulatory approval, sufficient scientific evidence to allow conclusions on effectiveness, evidence that the technology improves net health outcomes, evidence that the technology is as beneficial as established methods, and availability of the technology outside investigational settings. In this assessment, all 5 criteria were judged to have been met. The primary benefit of TAVR is the ability to treat AS in patients who would otherwise be ineligible for surgical aortic valve replacement. It may also be useful for patients at high surgical risk by potentially reducing periprocedural complications and avoiding the morbidity and recovery from undergoing heart surgery. Potential harms include the need for conversion to an open procedure, perioperative death, myocardial infarction, stroke, bleeding, valve embolization, aortic regurgitation, heart block that requires a permanent pacemaker, renal failure, pulmonary failure, and major vascular complications such as cardiac perforation or arterial dissection. Potential long-term harms include death, stroke, valve failure or clotting, and endocarditis. As highlighted at the February 2012 California Technology Assessment Forum meeting, the dispersion of this technology to new centers across the United States must proceed with careful thought given to training and proctoring multidisciplinary teams to become new centers of excellence.

CONCLUSIONS

TAVR is a potentially lifesaving procedure that may improve quality of life for patients at high risk for surgical AVR. However, attention needs to be paid to appropriate patient selection, their preoperative evaluation, surgical techniques, and postoperative care to preserve and improve on the results attained in the Placement of Aortic Transcatheter Valve trial. Specialty societies are collaborating to ensure that this happens in a rational and comprehensive manner.

Transcatheter aortic valve implantation reduces sympathetic activity and normalizes arterial spontaneous baroreflex in patients with aortic stenosis

OBJECTIVES

This study sought to measure muscle sympathetic nerve activity (MSNA) in patients with aortic stenosis (AS) before and after transcatheter aortic valve implantation (TAVI) and to compare MSNA with that of control patients.

BACKGROUND

TAVI is an emerging therapeutic option in patients with severe AS at high risk of open heart surgery. Whether patients with AS have increased sympathetic activity remains to be established, and the effects of TAVI on the sympathetic nervous system are also unknown.

METHODS

We prospectively enrolled 14 patients with severe symptomatic AS treated by TAVI. Fourteen control patients matched for age, body mass index, and unscathed of AS were also included. All patients underwent MSNA and arterial baroreflex gain assessment at baseline and 1 week after TAVI for AS patients.

RESULTS

Patients with AS had lower blood pressure (BP) levels, a significant increase in MSNA (61.0 ± 1.7 burst/min vs. 55.4 ± 1.4 burst/min; p < 0.05), and a decrease in arterial baroreflex gain (2.13 ± 0.14% burst/mm Hg vs. 3.32 ± 0.19% burst/mm Hg; p < 0.01) compared with matched control patients. The TAVI procedures induced an increase in BP associated with a significant decrease in MSNA (from 61.0 ± 1.7 burst/min to 54.1 ± 1.0 burst/min; p < 0.01) and was associated with a significant increase in arterial baroreflex gain (from 2.13 ± 0.14% burst/mm Hg to 3.49 ± 0.33% burst/mm Hg; p < 0.01).

CONCLUSIONS

We report for the first time, through direct measurement of nerve activity, that patients with AS have increased sympathetic nervous system activity associated with a decrease in sympathetic baroreflex gain and that TAVI normalizes these parameters. This study provides evidence of a new beneficial effect of TAVI, namely, normalization of sympathetic nervous system hyperactivity.

A meta-analysis of mortality and major adverse cardiovascular and cerebrovascular events following transcatheter aortic valve implantation versus surgical aortic valve replacement for severe aortic stenosis

The purpose of this meta-analysis was to compare postprocedural mortality and major adverse cardiovascular and cerebrovascular events between transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) for severe aortic stenosis. Seventeen studies (n = 4,659) comparing TAVI (n = 2,267) and SAVR (n = 2,392) were included. End points were baseline logistic European System for Cardiac Operative Risk Evaluation score, all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, transient ischemic attack, and major bleeding events. Mean differences or risk ratios with 95% confidence intervals were computed, and p values <0.05 were considered significant. The population was matched for risk between the 2 groups on the basis of logistic European System for Cardiac Operative Risk Evaluation score for all outcomes except 30-day all-cause mortality, which had a high-risk population in the TAVI group (p = 0.02). There was no significant difference found in all-cause mortality at 30 days (p = 0.97) and at an average of 85 weeks (p = 0.07). There was no significant difference in cardiovascular mortality (p = 0.54) as well as the incidence of myocardial infarction (p = 0.59), stroke (p = 0.36), and transient ischemic attack (p = 0.85) at averages of 86, 72, 66, and 89 weeks, respectively. Compared with patients who underwent TAVI, those who underwent SAVR had a significantly higher frequency of major bleeding events (p <0.0001) at mean follow-up of 66 weeks. In conclusion, TAVI has similar cardiovascular and all-cause mortality to SAVR at early and long-term follow-up. TAVI is superior to SAVR for major bleeding complications and noninferior to SAVR for postprocedural myocardial infarctions and cerebrovascular events. TAVI is a safe alternative to SAVR in selected high-risk elderly patients with severe aortic stenosis.

Use of transaortic, transapical, and transcarotid transcatheter aortic valve replacement in inoperable patients

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is an effective treatment in patients with severe aortic stenosis unsuitable for surgical aortic valve replacement (SAVR). This study evaluated the early experience with the posttrial application of TAVR, with specific focus on non-transfemoral (TF) access.

METHODS

All patients who underwent posttrial TAVR at Emory University from November 2011 to April 2012 were reviewed. During this time, 44 posttrial TAVRs were performed: TF in 18, transapical in 11, transaortic in 12, and transcarotid in 3.

RESULTS

A total of 40.9% of all patients were candidates for TF implantation. Mean age was 78.2 ± 11.3 years, and 34.1% were women. Mean ejection fraction was 0.463 ± 0.164, and 90.2% had New York Heart Association class III to IV heart failure. Fifty percent were diabetic, 27.3% had moderate to severe chronic obstructive pulmonary disease, and 20.5% had a prior stroke. The mean creatinine was 1.63 ± 1.74 mg/dL, 9.1% required preoperative dialysis, and 61.4% had undergone prior cardiac operations. No patients had postoperative myocardial infarction, stroke, or required new dialysis. Intraoperative vascular complications occurred in 11.4%. No patient had more than mild perivalvular leak by transthoracic echocardiography at discharge. Mean postoperative ventilator time was 17.8 ± 40.1 hours. Intensive care unit length of stay was 58.0 ± 67.0 hours. Postoperative hospital length of stay was 6.1 ± 4.7 days. The 30-day mortality was 6.8% (3 of 44) for all patients, despite a mean The Society of Thoracic Surgeons Predicted Risk of Mortality score of 12.6.

CONCLUSIONS

Less than half of patients deemed appropriate for posttrial TAVR were candidates for TF implantation. The use of all available access routes leads to excellent outcomes in patients deemed inoperable.

Surgical risk algorithm as a measure of successful adoption of transapical transcatheter aortic valve implantation

OBJECTIVE

This study was performed to assess the Society of Thoracic Surgeons (STS) score as a measure of successful adoption of transapical transcatheter aortic valve implantation (TAVI).

METHODS

The STS score for estimated surgical mortality was calculated and used to select the first 140 consecutive patients undergoing transapical TAVI. The STS score also was used to estimate postoperative morbidity. The comparisons were made between the observed and estimated mortality and morbidity in the entire group, as well as in the first 35, second 35, and last 70 consecutive patients.

RESULTS

The differences in outcomes between the first 35, second 35, and last 70 patients were statistically significant for surgical mortality (20.0% vs 14.3% vs 2.9%; P = .045), composite morbidity/mortality (34.3% vs 40.1% vs 15.7%; P = .020), and long length of stay (34.3% vs 45.7% vs 18.6%; P = .027). There were trends of marked decreases in prolonged ventilation (11.4% vs 20.0% vs 4.3%; P = .061), and acute renal failure (14.3% vs 20.0% vs 4.3%; P = .059). In the first 70 patients there were no significant differences between observed and STS estimated incidences in mortality and composite mortality/major morbidity. In the latter 70 patients the observed incidences were lower than STS predicted values in mortality (2.9% vs 9.6%; P = .056), composite major morbidity/mortality (15.7% vs 33.8%; P = .001), and prolonged ventilation (4.3% vs 25.1%; P < .0001).

CONCLUSIONS

Only after a protracted learning curve did the anticipated benefits of transapical TAVI materialize for patients at high risk for surgery as predicted by the STS risk algorithms.

A meta-analysis of transcatheter aortic valve implantation versus surgical aortic valve replacement

BACKGROUND

Our preliminary meta-analysis suggests that transcatheter aortic valve implantation (TAVI) may not reduce the 30-day mortality rate over surgical aortic valve replacement (AVR) in high-risk patients with severe aortic stenosis (AS). We performed an updated formal meta-analysis of TAVI vs AVR for reduction not only of early but also of late all-cause mortality in AS.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through October 2012. Eligible studies were randomized controlled trials or adjusted observational comparative studies of TAVI vs AVR enrolling individuals with AS and reporting early (30-day or in-hospital) or late all-cause mortality, or both, as an outcome. Odds ratios or hazard ratios with 95% confidence intervals (adjusted odds ratios or hazard ratios in case of observational studies) were abstracted from each study.

RESULTS

We identified two randomized trials and 15 adjusted observational studies enrolling 4,873 patients with severe AS. Pooled analysis suggested no significant difference in early (odds ratio, 0.92; 95% confidence interval, 0.70 to 1.19) and midterm (3-month to 3-year) total mortality (hazard ratio, 0.99; 95% confidence interval, 0.83 to 1.17) among patients assigned to TAVI vs AVR. Exclusion of any single study from the analysis did not substantively alter the overall result of our analysis. No evidence of significant publication bias was found.

CONCLUSIONS

Our meta-analysis of data of approximately 5,000 patients from 17 studies showed that TAVI is likely ineffective in reducing early and midterm all-cause mortality vs AVR in high-risk patients with AS.

Transcatheter aortic valve repair, imaging, and electronic imaging health record

Degenerative aortic stenosis (AS) is a common valvular pathology in developed nations. Secondary to advanced age and often multiple co-morbidities, a significant percentage of patients are not considered surgical candidates. For these high-risk patients, transcatheter aortic valve replacement (TAVR) is a rapidly emerging less-invasive treatment alternative. Because of the lack of direct exposure and visualization of the operative field, pre-procedural planning and intra-procedural guidance relies on imaging. Large 3-dimensional data files are acquired, which are reconstructed on advanced workstations during review and interpretation. Optimally, the imaging data is organized into a comprehensive digital file as an integral part of the electronic health record (EHR) following the patient. This manuscript will discuss the role of image data management in the context of TAVR.

Determinants and outcomes of acute transcatheter valve-in-valve therapy or embolization: a study of multiple valve implants in the U.S. PARTNER trial (Placement of AoRTic TraNscathetER Valve Trial Edwards SAPIEN Transcatheter Heart Valve)

OBJECTIVES

This study investigated the determinants and outcomes of acute insertion of a second transcatheter prosthetic valve (TV) within the first (TV-in-TV) or transcatheter valve embolization (TVE) after transcatheter aortic valve replacement (TAVR).

BACKGROUND

TAVR failure can occur with both TV-in-TV and TVE as a consequence of TAVR malpositioning. Only case reports and limited series pertaining to these complications have been reported to date.

METHODS

Patients undergoing TAVR in the PARTNER (Placement of AoRTic TraNscathetER Valve Trial Edwards SAPIEN Transcatheter Heart Valve) randomized trial (cohorts A and B) and accompanying registries were studied. Data were dichotomized for those with and without TV-in-TV or TVE, respectively.

RESULTS

From a total of 2,554 consecutive patients, 63 (2.47%) underwent TV-in-TV and 26 (1.01%) TVE. The indication for TV-in-TV was significant aortic regurgitation in most patients, often due not only to malpositioning but also to leaflet dysfunction. Despite similar aortic valve function on follow-up echoes, TV-in-TV was an independent predictor of 1-year cardiovascular mortality (hazard ratio [HR]: 1.86, 95% confidence interval [CI]: 1.03 to 3.38, p = 0.041), with a nonsignificant trend toward greater all-cause mortality (HR: 1.43, 95% CI: 0.88 to 2.33, p = 0.15). Technical and anatomical reasons accounted for most cases of TVE. A multivariable analysis found TVE to be an independent predictor of 1-year mortality (HR: 2.68, 95% CI: 1.34 to 5.36, p = 0.0055) but not cardiovascular mortality (HR: 1.30, 95% CI: 0.48 to 3.52, p = 0.60).

CONCLUSIONS

Acute TV-in-TV and TVE are serious sequelae of TAVR, often resulting in multiple valve implants. They carry an excess of mortality and are caused by anatomic and technical factors, which may be avoidable with judicious procedural planning.

Prognostic value of myocardial injury following transcatheter aortic valve implantation

There is a lack of clarity concerning the clinical implications of myocardial injury occurring after transcatheter aortic valve implantation (TAVI) procedures. The aim of this study was to determine the incidence, degree, and timing of myocardial injury associated with TAVI procedures and to evaluate its 1-year prognostic value. Among 68 consecutive patients (mean age 80.9 ± 6.4 years) treated with TAVI, 3 patients who died within 24 hours, precluding cardiac biomarker measurements, and 3 patients with major procedural complications were excluded. Cardiac troponin I, creatine kinase-MB, and creatinine levels were determined at baseline and 6, 12, 24, 48, and 72 hours after TAVI. All complications were defined according to the Valve Academic Research Consortium. Myocardial injury was observed in all patients (n = 62), as determined by an increase in cardiac troponin I (median peak at 12 hours 3.8 μg/L, interquartile range 1.8 to 25.67), and a higher degree of myocardial injury was observed in patients (n = 9) who developed acute kidney injury (AKI) (p = 0.026). Periprocedural myocardial infarction was not found. At 1-year follow-up, 5 patients had died, and 7 patients had been hospitalized for heart failure. The development of AKI, not the degree of peak cardiac troponin I (p = 0.348), was identified as the only strong independent predictor of 1-year mortality from any cause (including heart failure) after TAVI (hazard ratio 4.74, 95% confidence interval 1.12 to 20.03, p = 0.034). In conclusion, TAVI was systematically associated with myocardial injury, occurring with a higher degree in patients who developed AKI. However, the simultaneous development of AKI occurring after TAVI is the strongest predictor of 1-year mortality.

Introducing transapical aortic valve implantation (part 1): effect of a structured training program on clinical outcome in a series of 500 procedures

OBJECTIVES

The purpose of the present study was to test whether the cumulative knowledge from the field of transapical transcatheter aortic valve implantation, when incorporated into a structured training and then gradually dispersed by internal proctoring, might eliminate the negative effect of the learning curve on the clinical outcomes.

METHODS

The present study was a retrospective, single-center, observational cohort study of prospectively collected data from all 500 consecutive high-risk patients undergoing transapical transcatheter aortic valve implantation at our institution from April 2008 to December 2011. Of the 500 patients, 28 were in cardiogenic shock. Differences during the study period in baseline characteristics, procedural and postprocedural variables, and survival were analyzed using different statistical methods, including cumulative sum charts.

RESULTS

The overall 30-day mortality was 4.6% (95% confidence interval, 3.1%-6.8%) and was 4.0% (95% confidence interval, 2.6%-6.2%) for patients without cardiogenic shock. Throughout the study period, no significant change was seen in the 30-day mortality (Mann-Whitney U test, P = .23; logistic regression analysis, odds ratio, 0.83 per 100 patients; 95% confidence interval, 0.62-1.12; P = .23). Also, no difference was seen in survival when stratified by surgeon (30-day mortality, P = .92). An insignificant change was seen toward improved overall survival (hazard ratio, 0.90 per 100 patients; 95% confidence interval, 0.77-1.04; P = .15).

CONCLUSIONS

The structured training program can be used to introduce transapical transcatheter aortic valve implantation and then gradually dispersed by internal proctoring to other members of the team with no concomitant detriment to patients.

Transcatheter aortic valve implantation: recommendations for practice based on a multidisciplinary review including cost-effectiveness and ethical and organizational issues

Transcatheter aortic valve implantation (TAVI) is a relatively new technology for the treatment of severe and symptomatic aortic valve stenosis. TAVI offers an alternative therapy for patients unable to be treated surgically because of contraindications or severe comorbidities. It is being rapidly dispersed in Canada, as it is worldwide. The objective of this article is to present our recommendations for the use of TAVI, based on a multidisciplinary evaluation of recently published evidence. We systematically searched and summarized published data (2008-2011) on benefits, risks, and cost-effectiveness of TAVI. We also examined ethical issues and organizational aspects of delivering the intervention. We discussed the soundness and applicability of our recommendations with clinical experts active in the field. The published TAVI results for high-risk and/or inoperable patients are promising in terms of survival, function, quality of life, and cost-effectiveness, although we noted large variability in the survival rates at 1 year and in the frequency of important adverse outcomes such as stroke. Until more data from randomized controlled trials and registries become available, prudence and discernment are necessary in the choice of patients most likely to benefit. Patients need to be well-informed about gaps in the evidence base. Our recommendations support the use of TAVI in the context of strict conditions with respect to patient eligibility, the patient selection process, organizational requirements, and the tracking of patient outcomes with a mandatory registry.

Prediction of in-hospital death following aortic valve replacement: a new accurate model

OBJECTIVES

Aortic valve replacement (AVR) is accepted as the standard treatment for severe symptomatic aortic valve stenosis and regurgitation. As novel treatments are introduced for patients at high risk for conventional surgery, it is important to have models that accurately predict procedural risk. The aim of this study was to develop and validate a risk-stratification model to predict in-hospital risk of death for patients undergoing AVR and to compare the model with existing algorithms.

METHODS

We reviewed data from the Central Cardiac Adult Database, which holds prospectively collected clinical information on all adult patients undergoing cardiac surgery in National Health Service (NHS) hospitals and some private providers in the UK and Ireland. We included all the patients undergoing AVR with or without coronary artery bypass grafting. The study population consists of 55 157 patients undergoing surgery between 1 April 2001 and 31 March 2009. The model was built using data from April 2001 to March 2008 and validated using data from patients undergoing surgery from April 2008 to March 2009. The model was compared against the additive and logistic EuroSCORE models and a valve-specific risk-prediction model.

RESULTS

The final multivariable model includes items describing cardiovascular risk status and procedural factors. Applying the model to the independent validation dataset provided a c-statistic (index of rank correlation) of 0.791, which was substantially better than that achieved by previously developed risk models in Europe, and significantly improved risk prediction in higher-risk patients.

CONCLUSIONS

We have produced an accurate risk model to predict outcome following AVR surgery. It will be of use for patient selection and informed consent, and of particular interest in defining those patients at high risk who may benefit from novel approaches to AVR.

[Transcatheter aortic valve replacement: when should it be used in aortic stenosis?]

30% of patients with significant aortic stenosis are not considered for operative aortic valve replacement because of the high perioperative risk. An alternative catheter based option for these patients is the transcatheter aortic valve replacement (TAVI). In general, there are two approaches for TAVI: transfemoral and transapical. Transfemoral aortic valve replacement is performed by transcatheter replacement of an aortic valve via the femoral arteries. Transapical valve replacement is achieved by transcatheter implantation via the fifth intercostal space. The most common complications are vessel injuries, bleeding complications, new onset of AV-block, development of paravalvular insufficiency, acute kidney injury, stroke and TIA. The first long-term observations suggest positive results. First clinical trials in a high-risk population show a promising outcome. Therefore TAVI offers a reasonable therapy option for patients with high perioperative risk. Further long-term clinical trials are still pending.

Transcatheter aortic valve implantation 10-year anniversary: review of current evidence and clinical implications

Surgical aortic valve replacement (SAVR) is currently the standard of care to treat patients with severe symptomatic aortic stenosis (AS) and is generally accepted to alleviate symptoms and prolong survival. Based on the results of randomized trials, transcatheter aortic valve implantation (TAVI) is the new standard of care for patients with symptomatic AS who are deemed 'inoperable'. Debatably, TAVI is also an alternative to SAVR in selected patients who are at high risk but operable. As we approach 10 years of clinical experience with TAVI, with over 50 000 implantations in 40 countries, a review of the current literature and clinical outcomes with this rapidly evolving technology is appropriate.

Transcatheter aortic valve implantation after previous mechanical mitral valve replacement: expanding indications?

BACKGROUND

Cardiac operation for severe aortic stenosis after previous mitral valve replacement is a surgical challenge in older patients with multiple morbidities. Transcatheter aortic valve implantation (TAVI) after previous mechanical mitral valve replacement has been considered a high-risk procedure, owing to possible interference with the mitral valve prosthesis.

METHODS

Since August 2008, 5 female high-risk patients with severe aortic stenosis and previous mitral valve replacement (mean ± SD age, 80 ± 5.1 years; logistic EuroSCORE, 39.3% ± 20.5%) underwent TAVI with a pericardial xenograft valve that was fixed with a stainless steel, balloon-expandable stent (Edwards Lifesciences SAPIEN). We used a transapical approach in 4 patients and a transfemoral approach in 1 patient. Transesophageal echocardiography and multidetector computed tomography were used for preoperative planning and assessment of operation feasibility. The mean distance between the aortic annulus and the mitral valve prosthesis was 10 ± 1 mm (range, 9-11 mm).

RESULTS

TAVI was performed successfully in all 5 patients. There was no direct or functional interference with the mechanical mitral valve prostheses. Echocardiography revealed good valve function with no more than mild paravalvular incompetence early in the postoperative period and during routine follow-up. There were no neurologic events. After an initially uneventful course with good aortic valve function at the most recent echocardiography evaluation, however, 2 of the patients died from fulminant pneumonia on postoperative days 4 and 48.

CONCLUSION

TAVI is technically feasible in high-risk patients after previous mechanical mitral valve replacement; however, careful patient selection is mandatory with respect to preoperative clinical status and anatomic dimensions regarding the distance between aortic annulus and mitral valve prosthesis.

Reversal of angiodysplasia-derived anemia after transcatheter aortic valve implantation

Aortic valve stenosis associated with angiodysplasia (Heyde's syndrome) and consequent anemia had previously been reported to benefit from surgical aortic valve replacement. In this clinical case an 89-year-old patient with chronic angiodysplasia-derived anemia, characterized by acute phases of active gastrointestinal bleeding experienced a normalization of hemoglobin values after a trans-catheter aortic valve implantation (TAVI) of a self-expandable aortic valve prosthesis (CoreValve, Medtronic Inc., Minneapolis, MN, USA). This is the first, to our knowledge, reported clinical case of remission of angiodysplasia-derived anemia after TAVI.

Sutureless aortic bioprosthesis in severe aortic root calcification: an innovative approach

Aortic valve replacement (AVR) in patients with severe aortic root calcification is technically a very difficult procedure which requires a long cardiopulmonary bypass (CPB) time, especially in patients undergoing complex procedures such as multivalve or valve and coronary surgery. We report a case of successful AVR with an innovative approach in a patient with an extensively calcified aortic root and concomitant tricuspid valve regurgitation who underwent mitral valve replacement 20 years ago.

Computed tomography in the evaluation for transcatheter aortic valve implantation (TAVI)

If left untreated, symptomatic, severe aortic stenosis (AS) is associated with a dismal prognosis. Open-heart surgical valve replacement is the treatment of choice and is associated with excellent short and long-term outcome. However, many older patients with multiple co-morbidities and anticipated increased surgical risk are excluded from surgical intervention. For these patients, transcatheter aortic valve implantation (TAVI) is emerging as a viable treatment alternative. Transcatheter valvular heart procedures are characterized by lack of exposure and visualization of the operative field, therefore relying on image guidance, both for patient selection and preparation and the implantation procedure itself. This article describes the role of multi-detector row computed tomography (MDCT) for detailed assessment of the aortic valve, aortic root, and iliac arteries in the context of TAVI.

Midterm stability and hemodynamic performance of a transfemorally implantable nonmetallic, retrievable, and repositionable aortic valve in patients with severe aortic stenosis. Up to 2-year follow-up of the direct-flow medical valve: a pilot study

BACKGROUND

Misplacement during percutaneous aortic valve implantation can be associated with severe complications. The direct flow medical (DFM) valve is repositionable and retrievable; however, the nonmetallic inflatable and conformable design of the valve results in less radial force, which may have an impact on stability and valve function over time. We, therefore, analyzed the midterm stability of the position, shape, and hemodynamic performance of the DFM percutaneous aortic valve.

METHODS AND RESULTS

Sixteen symptomatic high-risk for surgery patients with aortic stenosis and a logistic EuroSCORE >20 underwent implantation and were the subject of this analysis. Clinical, echocardiographic, and dual-source multislice computed tomography data were obtained during 2-year follow-up. The 1- and 2-year survival rates were 81% and 69%, respectively. The dual-source multislice computed tomography follow-up indicated no changes in position, diameter, and orifice area of the DFM valve over time. Echocardiography revealed a significant decrease of the mean gradient from baseline (50.1±11.3 mm Hg) to 30 days (19.6±5.7 mm Hg, P<0.001), which remained stable over 2 years. The aortic valve area increased from 0.57±0.15 cm(2) at baseline to 1.47±0.35 cm(2) at 30 days (P<0.001) and did not significantly change during 2-year follow-up. Of the patients, 73% had no aortic regurgitation (AR) and 27% had minimal AR.

CONCLUSIONS

In this preliminary series, the 2-year follow-up data of patients, in whom the nonmetallic, repositionable, and retrievable DFM valve was successfully implanted, show stability of the position, shape, and hemodynamic performance, with no AR in most patients.

Health-Related Quality of Life After Transcatheter Aortic Valve Replacement in Inoperable Patients With Severe Aortic Stenosis

Background—

Transcatheter aortic valve replacement (TAVR) has been shown to improve survival compared with standard therapy in patients with severe aortic stenosis who cannot have surgery. The effects of TAVR on health-related quality of life have not been reported from a controlled study.

Methods and Results—

The Placement of Aortic Transcatheter Valves (PARTNER) trial randomized patients with symptomatic, severe aortic stenosis who were not candidates for surgical valve replacement to TAVR (n=179) or standard therapy (n=179). Health-related quality of life was assessed at baseline and at 1, 6, and 12 months with the Kansas City Cardiomyopathy Questionnaire (KCCQ) and the 12-item Short Form-12 General Health Survey (SF-12). The primary end point was the KCCQ overall summary score (range, 0–100; higher=better). At baseline, mean KCCQ summary scores (35±20) and SF-12 physical summary scores (28±7) were markedly depressed. Although the KCCQ summary score improved from baseline in both groups, the extent of improvement was greater after TAVR compared with control at 1 month (mean between-group difference, 13 points; 95% confidence interval, 8–19; P <0.001) with larger benefits at 6 months (mean difference, 21 points; 95% confidence interval, 15–27; P <0.001) and 12 months (mean difference, 26 points; 95% confidence interval, 19–33; P <0.001). At 12 months, TAVR patients also reported higher SF-12 physical and mental health scores with mean differences compared with standard care of 5.7 and 6.4 points, respectively ( P <0.001 for both comparisons).

Conclusions—

Among inoperable patients with severe aortic stenosis, compared with standard care, TAVR resulted in significant improvements in health-related quality of life that were maintained for at least 1 year.

Clinical Trials Registration—

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

Intensified thermal management for patients undergoing transcatheter aortic valve implantation (TAVI)

Background

Transcatheter aortic valve implantation via the transapical approach (TAVI-TA) without cardiopulmonary bypass (CPB) is a minimally invasive alternative to open-heart valve replacement. Despite minimal exposure and extensive draping perioperative hypothermia still remains a problem.

Methods

In this observational study, we compared the effects of two methods of thermal management on the perioperative course of core temperature. The methods were standard thermal management (STM) with a circulating hot water blanket under the patient, forced-air warming with a lower body blanket and warmed infused fluids, and an intensified thermal management (ITM) with additional prewarming using forced-air in the pre-operative holding area on the awake patient.

Results

Nineteen patients received STM and 20 were treated with ITM. On ICU admission, ITM-patients had a higher core temperature (36.4 ± 0.7°C vs. 35.5 ± 0.9°C, p = 0.001), required less time to achieve normothermia (median (IQR) in min: 0 (0-15) vs. 150 (0-300), p = 0.003) and a shorter period of ventilatory support (median (IQR) in min: 0 (0-0) vs. 246 (0-451), p = 0.001).

Conclusion

ITM during TAVI-TA reduces the incidence of hypothermia and allows for faster recovery with less need of ventilatory support.

Multidetector computed tomography in transcatheter aortic valve implantation

Aortic stenosis is a common disorder. Aortic valve replacement is indicated in symptomatic patients with severe aortic stenosis, as the prognosis of untreated patients is poor. Nevertheless, many patients pose a prohibitively high surgical risk and are not candidates for surgical valve replacement. Transcatheter aortic valve implantation (TAVI) is a novel method to treat selected high-risk patients with aortic stenosis. Patient screening and anatomic measurements of the aortic root are of great importance to ensure procedural success and appropriate patient selection. Multidetector computed tomography (CT) is playing an increasingly important role in patient screening protocols before TAVI, provides detailed anatomic assessment of the aortic root and valve annulus, assesses the suitability of iliofemoral access, and determines appropriate coaxial angles to optimize the valve implantation procedure. Additionally, CT is providing a greater understanding of medium-term valve durability and integrity. This review outlines an evolving role for CT angiography in support of a TAVI program and describe step by step how CT can be used to enhance the procedure and provide a practical guide for the utilization of CT angiography in support of a transcatheter aortic valve program.

Incidence, predictive factors, and prognostic value of myocardial injury following uncomplicated transcatheter aortic valve implantation

OBJECTIVES

This study sought to: 1) determine the incidence, degree, and timing of the rise in serum cardiac markers of myocardial injury associated with uncomplicated transcatheter aortic valve implantation (TAVI); and 2) evaluate the predictive factors and prognostic value of myocardial injury associated with TAVI.

BACKGROUND

Very few data exist on the occurrence and clinical relevance of myocardial injury during TAVI procedures.

METHODS

A total of 101 patients who underwent successful TAVI (transfemoral [TF] approach, n = 38; transapical [TA] approach, n = 63) were included. Creatine kinase-MB (CK-MB) and cardiac troponin T (cTnT) levels were determined at baseline and at 6 to 12, 24, 48, and 72 h following TAVI.

RESULTS

TAVI was associated with some degree of myocardial injury in 99% of the patients (TF: 97%, TA: 100%) as determined by a rise in cTnT (maximal value, 0.48 μg/l, interquartile range [IQR]: 0.24 to 0.82 μg/l) and in 77% of the patients (TF: 47%, TA: 95%) as determined by a rise in CK-MB (maximal value, 18.6 μg/l; IQR: 11.0 to 27.4 μg/l). TA approach and baseline renal dysfunction were associated with a higher increase in biomarkers of myocardial injury (p < 0.01 for both). A larger myocardial injury was associated with a smaller improvement of left ventricular ejection fraction (LVEF) (p < 0.01). The degree of rise in cTnT was an independent predictor of cardiac mortality at 9 ± 10 months of follow-up (hazard ratio: 1.14 per each increase of 0.1 μg/l, 95% confidence interval: 1.02 to 1.28, p = 0.028).

CONCLUSIONS

TAVI was systematically associated with some degree of myocardial injury, with TA approach and baseline renal dysfunction determining a higher increase in biomarkers of myocardial injury. A greater degree of myocardial injury was associated with less improvement in LVEF and a higher cardiac mortality at follow-up.