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

Transcatheter aortic valve implantation for the treatment of severe symptomatic aortic stenosis in patients at very high or prohibitive surgical risk: acute and late outcomes of the multicenter Canadian experience

OBJECTIVES

The aim of this study was: 1) to evaluate the acute and late outcomes of a transcatheter aortic valve implantation (TAVI) program including both the transfemoral (TF) and transapical (TA) approaches; and 2) to determine the results of TAVI in patients deemed inoperable because of either porcelain aorta or frailty.

BACKGROUND

Very few data exist on the results of a comprehensive TAVI program including both TA and TF approaches for the treatment of severe aortic stenosis in patients at very high or prohibitive surgical risk.

METHODS

Consecutive patients who underwent TAVI with the Edwards valve (Edwards Lifesciences, Inc., Irvine, California) between January 2005 and June 2009 in 6 Canadian centers were included.

RESULTS

A total of 345 procedures (TF: 168, TA: 177) were performed in 339 patients. The predicted surgical mortality (Society of Thoracic Surgeons risk score) was 9.8 +/- 6.4%. The procedural success rate was 93.3%, and 30-day mortality was 10.4% (TF: 9.5%, TA: 11.3%). After a median follow-up of 8 months (25th to 75th interquartile range: 3 to 14 months) the mortality rate was 22.1%. The predictors of cumulative late mortality were peri-procedural sepsis (hazard ratio [HR]: 3.49, 95% confidence interval [CI]: 1.48 to 8.28) or need for hemodynamic support (HR: 2.58, 95% CI: 1.11 to 6), pulmonary hypertension (PH) (HR: 1.88, 95% CI: 1.17 to 3), chronic kidney disease (CKD) (HR: 2.30, 95% CI: 1.38 to 3.84), and chronic obstructive pulmonary disease (COPD) (HR: 1.75, 95% CI: 1.09 to 2.83). Patients with either porcelain aorta (18%) or frailty (25%) exhibited acute outcomes similar to the rest of the study population, and porcelain aorta patients tended to have a better survival rate at 1-year follow-up.

CONCLUSIONS

A TAVI program including both TF and TA approaches was associated with comparable mortality as predicted by surgical risk calculators for the treatment of patients at very high or prohibitive surgical risk, including porcelain aorta and frail patients. Baseline (PH, COPD, CKD) and peri-procedural (hemodynamic support, sepsis) factors but not the approach determined worse outcomes.

Severe aortic regurgitation after percutaneous transcatheter aortic valve implantation: on the importance to clarify the underlying pathophysiology

Severe symptomatic aortic stenosis in a 90-year-old man was treated with percutaneous aortic valve implantation (TAVI) with a 29-mm CoreValve Revalving system. Following implantation, severe aortic regurgitation occurred. Echocardiography showed a small paravalvular and a huge valvular leakage, probably due to one malfunctioning valve leaflet. Concerning this pathophysiology, a further TAVI was performed using a second 29-mm CoreValve Revalving system, as a "valve-in-valve" implantation.

Transcatheter aortic valve implantation: review of the nature, management, and avoidance of procedural complications

Transcatheter aortic valve implantation (TAVI) is becoming a reality in the management of patients with severe aortic stenosis and high or prohibitive risk for standard surgical management. Current understanding of the potential adverse events associated with this procedure is limited. Risks associated with TAVI differ from those related to surgical valve replacement and include vascular injury; stroke; cardiac injury such as heart block, coronary obstruction, and cardiac perforation; paravalvular leak; and valve misplacement. The clinical experience of multiple centers experience with different valve implantation systems and techniques was reviewed. Awareness of how complications occur might help in their avoidance, recognition, and management. Ultimately, improved understanding of the potential complications associated with TAVI might help improve outcomes and allow wider application of this therapy.

[Transcatheter aortic valve implantation: surgeon's view]

BACKGROUND AND PURPOSE

The technology of catheter- based aortic valve implantation is a new, less invasive therapeutic option for patients with symptomatic high-grade aortic stenosis. The present paper aims to demonstrate that optimal therapy should be provided by a multidisciplinary team consisting of cardiac surgeons, cardiologists and cardioanesthesiologists in a hybrid suite.

PATIENTS AND METHODS

From June 2007 to April 2009, 234 patients have been treated by transcatheter aortic valve implantation through different access sites (n = 168 femoral artery, n = 56 left ventricular apex, n = 7 subclavian artery, n = 3 ascending aorta) at the German Heart Center Munich, Germany. An algorithm for the choice of the most appropriate access site for the individual patient was established.

RESULTS

The 30-day mortality was 11.2% in this high-risk patient cohort. A certain number of periprocedural complications required surgical management. There was a considerable clinical improvement of the patients 6 months after the procedure.

CONCLUSION

Integrating the new methods of aortic valve implantation into a cardiac surgery program, all kinds of surgical and interventional treatment options may be offered to the patient with aortic stenosis by one multidisciplinary team. A qualified and safe performance of transcatheter aortic valve implantation and the management of potential complications require the presence of a hybrid suite.

Development of aortic valve implantation

Aortic valve stenosis is an important public-health problem in Europe and is predicted to increase with the aging population. Management of severe symptomatic aortic stenosis is by surgical replacement of the aortic valve whenever feasible. Improvement in the perioperative management has permitted surgical intervention in high-risk patients. However, patients refused surgery can now be managed by transcatheter techniques. These have opened new horizons for patients for whom conventional surgery is contraindicated or the technical complexity of the procedure is associated with considerable operative risk. The development of transcatheter aortic valve implantation, available technology, choice of approach, and future perspectives are discussed.

Percutaneous pulmonary and aortic valve insertion in Belgium: going for conditional reimbursement or waiting for further evidence?

OBJECTIVES

The aim of this study was to assess current evidence supporting the use of percutaneous heart valves (PHV) in degenerative aortic valve and congenital pulmonary outflow tract disease, as compared to conservative medical therapy or traditional surgical valve replacement.

METHODS

A systematic review of the literature on PHV was performed.

RESULTS

No randomized controlled trials (RCT) on PHV have been published so far. Only observational data from series and data presented at cardiology meetings are available. Both percutaneous aortic valve (PAV) and percutaneous pulmonary valve (PPV) seem feasible in the hands of an experienced team. Safety, however, seems to be a problem in PAV, as shown by the high 30-day and 6-month mortality rates.

CONCLUSIONS

Due to safety concerns, PAV reimbursement is not recommended and patients should only be subjected to PAV insertion within the boundaries of an RCT. In contrast, PPV implantation seems to be a safe and promising technology for which reimbursement under strict conditions may be recommended.

Transcatheter cardiac valve interventions

Currently aortic valve replacement is performed for patients with severe aortic stenosis and symptoms or objective pathophysiologic consequences such as left ventricular dysfunction. For transcatheter mitral valve interventions, the complex pathophysiology of mitral regurgitation with varying causes along with challenging imaging and delivery issues has led to slower than anticipated clinical introduction. Transcatheter pulmonary valve intervention was primarily designed to treat the difficult problem of right ventricular to pulmonary artery conduit stenosis in the congenital population. These techniques are reviewed in this article.

Survival after transapical and transfemoral aortic valve implantation: talking about two different patient populations

OBJECTIVE

Recently, suspicion had been expressed that survival might be impaired after antegrade transapical as opposed to retrograde transfemoral valve implantation in high-risk patients with aortic stenosis. We analyzed survival in patients undergoing transcatheter aortic valve implantation with special emphasis on the access site for implantation.

METHODS

Between June 2007 and February 2009, 203 high-risk patients (EuroSCORE, 22% +/- 14%; mean age, 81 +/- 7 years) underwent transcatheter aortic valve implantation via a transapical (n = 50) or transfemoral (n = 153) access. The transapical implantation technique was chosen only in patients who had no access through diseased femoral arteries.

RESULTS

Thirty-day survival was 88.8% after transfemoral versus 91.7% after transapical implantation (P = .918). The transapical group had a significantly higher preoperative brain natriuretic peptide value and a significantly higher incidence of peripheral vessel, cerebrovascular, and coronary heart disease. Death within 30 days was valve related in 25% (transapical) and 31% (transfemoral), cardiac in 25% and 13%, and noncardiac in 50% and 56%, respectively (no significant difference). Complications specific to the access site (peripheral vessel injury or apex complications) occurred in both groups, whereas neurologic events did not occur in the transapical group (P = .041).

CONCLUSIONS

Our patient and access site selection process, with the transfemoral technique considered the access site of first choice, results in comparable survival and morbidity for either transfemoral or transapical transcatheter aortic valve implantation. Both techniques are associated with certain access site-specific complications that require highly qualified management. The neurologic risk profile of the patients should be included in the decision-making process before transcatheter aortic valve implantation, inasmuch as neurologic events may be reduced with the transapical access.

Safety of percutaneous aortic valve insertion. A systematic review

Background

The technique of percutaneous aortic valve implantation (PAVI) for the treatment of severe aortic stenosis (AS) has been introduced in 2002. Since then, many thousands such devices have worldwide been implanted in patients at high risk for conventional surgery. The procedure related mortality associated with PAVI as reported in published case series is substantial, although the intervention has never been formally compared with standard surgery. The objective of this study was to assess the safety of PAVI, and to compare it with published data reporting the risk associated with conventional aortic valve replacement in high-risk subjects.

Methods

Studies published in peer reviewed journals and presented at international meetings were searched in major medical databases. Further data were obtained from dedicated websites and through contacts with manufacturers. The following data were extracted: patient characteristics, success rate of valve insertion, operative risk status, early and late all-cause mortality.

Results

The first PAVI has been performed in 2002. Because of procedural complexity, the original transvenous approach from 2004 on has been replaced by the transarterial and transapical routes. Data originating from nearly 2700 non-transvenous PAVIs were identified. In order to reduce the impact of technical refinements and the procedural learning curve, procedure related safety data from series starting recruitment in April 2007 or later (n = 1975) were focused on. One-month mortality rates range from 6.4 to 7.4% in transfemoral (TF) and 11.6 to 18.6% in transapical (TA) series. Observational data from surgical series in patients with a comparable predicted operative risk, indicate mortality rates that are similar to those in TF PAVI but substantially lower than in TA PAVI. From all identified PAVI series, 6-month mortality rates, reflecting both procedural risk and mortality related to underlying co-morbidities, range from 10.0-25.0% in TF and 26.1-42.8% in TA series. It is not known what the survival of these patients would have been, had they been treated medically or by conventional surgery.

Conclusion

Safety issues and short-term survival represent a major drawback for the implementation of PAVI, especially for the TA approach. Results from an ongoing randomised controlled trial (RCT) should be awaited before further using this technique in routine clinical practice. In the meantime, both for safety concerns and for ethical reasons, patients should only be subjected to PAVI within the boundaries of such an RCT.

Future of cardiac surgery: minimally invasive techniques in sutureless valve resection

Aortic valve replacement with mechanical or biological heart valves is the treatment of choice for aortic valve stenosis when it is symptomatic or with severe aortic stenosis (≤ 0.6 cm2/m2) or with left ventricular dysfunction. In an effort to improve the outcomes of patients with stented biological valves, stentless valves were introduced to clinical practices in the early 1990s. Theses valves were designed to be less obstructive, and thus result in a lower transvalvular gradient. Technically the implantations of these valves are more demanding resulting in longer cross clamp and bypass times. However, important comorbid conditions in elderly patients referred for aortic valve replacement require alternative treatment options with possible reductions of the extracorporeal bypass time and reliable hemodynamic features. In order to comply with these requirements, percutaneous valves and sutureless surgical valves have been developed. The percutaneous technique has the advantage of being performed without circulatory bypass but leaving the aortic calcifications in place, thereby resulting in a high degree of paravalvular insufficiency, atrioventricular block and strokes. The surgical approach has the advantage of removing all calcifications and the valves can be optimally implanted, resulting in minimal paravalvular leak with a low incidence of atrioventricular block and strokes; however, it requires cardiopulmonary bypass. In addition, it can be performed with a low mortality (<3% in isolated aortic replacement, even in older patients). This article reviews the various techniques, strength and limitations of these sutureless valves implanted in the aortic position.

Results of transfemoral or transapical aortic valve implantation following a uniform assessment in high-risk patients with aortic stenosis

OBJECTIVES

We sought to describe the results of a strategy offering either transfemoral or transapical aortic valve implantation in high-risk patients with severe aortic stenosis.

BACKGROUND

Results of transfemoral and transapical approaches have been reported separately, but rarely following a uniform assessment to select the procedure.

METHODS

Of 160 consecutive patients at high risk or with contraindications to surgery, referred between October 2006 and November 2008, 75 were treated with transcatheter aortic valve implantation. The transfemoral approach was used as the first option and the transapical approach was chosen when contraindications to the former were present. The valve used was the Edwards Lifesciences SAPIEN prosthesis.

RESULTS

Patients were age 82 +/- 8 years (mean +/- SD), in New York Heart Association functional classes III/IV, with predicted mean surgical mortalities of 26 +/- 13% using the European System for Cardiac Operative Risk Evaluation and 16 +/- 7% using the Society of Thoracic Surgeons Predicted Risk of Mortality. Fifty-one patients were treated via the transfemoral approach, and 24 via the transapical approach. The valve was implanted in 93% of the patients. Hospital mortality was 10%. Mean (+/- SD) 1-year survivals were 78 +/- 6% in the whole cohort, 81 +/- 7% in the transfemoral group, 74 +/- 9% in the transapical group (p = 0.22), and 60 +/- 10% in the first 25 patients versus 93 +/- 4% in the last 50 patients treated (p = 0.001). In multivariate analysis, early experience was the only significant predictor of late mortality.

CONCLUSIONS

Being able to offer either transfemoral or transapical aortic valve implantation, within a uniform assessment, expands the scope of the treatment of aortic stenosis in high-risk patients and provides satisfactory results at 1 year in this population. The results are strongly influenced by experience.

Transapical aortic valve implantation. Initial experience

We report our initial experience with transapical aortic valve implantation. All six of our patients were octogenarians, all had significant associated comorbid conditions and, according to the logistic EuroSCORE, their mortality was expected to be 22%. All procedures were performed successfully and there were no intraoperative or postoperative complications. Five patients were discharged between postoperative days 5 and 7 with normally functioning prostheses.

Antithrombotic management of patients with prosthetic heart valves: current evidence and future trends

Over 4 million people worldwide have received a prosthetic heart valve, and an estimated 300,000 valves are being implanted every year. Prosthetic heart valves improve quality of life and survival of patients with severe valvular heart disease, but the need for antithrombotic therapy to prevent thrombotic complications in valve recipients poses challenges for clinicians and patients. Here, we review antithrombotic therapies for patients with prosthetic heart valves and management of thromboembolic complications. Advances in antithrombotic therapy and valve technologies are likely to improve the management of patients with prosthetic heart valves in developed countries, but the most important unmet need and potential for benefit from these new therapies is in developing countries where a massive and rapidly increasing burden of valvular heart disease exists.

Electrocardiographic changes and clinical outcomes after transapical aortic valve implantation

BACKGROUND

Transapical aortic valve implantation (TAVI) for the treatment of severe aortic stenosis requires the insertion of a large catheter through the left ventricular apex. However, the electrocardiographic (ECG) changes associated with the incision and repair of the left ventricular apex and the potential damage to the conduction system caused by implanting a balloon-expandable valve in aortic position are not known. The objective of our study was to determine the incidence, type, and timing of ECG changes associated with TAVI.

METHODS

The standard 12-lead ECGs of 33 consecutive patients (mean age 81 +/- 9 years, 13 men) diagnosed with symptomatic severe aortic stenosis (valve area 0.62 +/- 0.16 cm(2)) who underwent TAVI with an Edwards-SAPIEN valve were analyzed at baseline (within 24 hours before the procedure), immediately (within 6 hours) after the procedure, at hospital discharge, and at 1-month follow-up.

RESULTS

There were no procedural deaths, and 30-day mortality was 6%. The incidence of complete left ventricular branch block (LBBB) and left anterior hemiblock (LAHB) increased from 9% and 3% at baseline to 27% and 36% after the procedure, respectively (P < .03 for both). A lower (ventricular) position of the valve relative to the hinge point of the anterior mitral leaflet was associated with a higher incidence of new LBBB (35% vs 0%, P = .029); and a greater valve size-aortic annulus ratio, with the occurrence of new LAHB (1.20 +/- 0.07 vs 1.14 +/- 0.06, P = .021). At 1-month follow-up, the rate of LBBB and LAHB decreased to 13% and 10%, respectively (P = not significant compared with baseline). There were no cases of new atrioventricular block, and no patient needed pacemaker implantation. Transient (<48 hours) ST-elevation changes, mostly in the anterior and/or lateral leads, occurred in 6 patients (18%) immediately after the procedure; but only 1 of these patients presented new Q waves at 1-month follow-up.

CONCLUSIONS

Transapical aortic valve implantation was associated with a significant but transient (<1 month) increase in LBBB and LAHB, with no patient requiring pacemaker implantation. These changes were partially related to both lower (more ventricular) valve positioning and greater valve oversizing. Transient (<48 hours) ST-segment elevation changes occurred in about one fifth of the patients after the procedure, but only a minority developed new Q waves in the ECG.

Transapical off-pump removal of the native aortic valve: a proof-of-concept animal study

OBJECTIVE

This study evaluates the feasibility of off-pump native aortic valve removal in preparation for transapical aortic valve replacement. Off-pump aortic valve replacement is performed by balloon predilatation of the native valve followed by insertion of a stented prosthesis. In patients with calcified annuli and cusps, particulate embolization, suboptimal prosthesis sizing, and perivalvular leaks may occur. Therefore, native valve removal may improve outcomes after transapical aortic valve replacement.

METHODS

The aortic cusps were sequentially removed from 10 pigs in an off-pump procedure. A temporary valve was inserted percutaneously into the ascending aorta to prevent aortic regurgitation. The electrocardiogram, coronary blood flow, and arterial, left atrial, and ventricular pressures were continuously monitored.

RESULTS

Removal of the aortic cusps caused a drop in diastolic arterial pressure and its equalization with left ventricular diastolic pressure. Systolic pressure decreased by 13.5%. Left atrial pressure increased by 86.0%. Coronary blood flow decreased by 39.9% and its pattern changed from mostly diastolic to mostly systolic. Electrocardiographic signs of ischemia appeared almost immediately. Percutaneous insertion of a temporary valve in the ascending aorta increased diastolic pressure and caused a tendency toward echocardiographic normalization.

CONCLUSIONS

Aortic valve removal in a healthy beating heart causes acute massive aortic regurgitation, hemodynamic instability, and the rapid onset of myocardial ischemia. Reduction of left ventricular volume overload, by placement of a temporary valve in the ascending aorta, mitigates myocardial distress, helps stabilize hemodynamic parameters, and may be a useful tool to allow surgical manipulations of the aortic valve and annulus during transapical aortic valve replacement procedures.

[Surgery or medical therapy for secondary mitral regurgitation?]

Mitral regurgitation (MR) is the second most frequent valve disease in Europe. In addressing the current therapy for MR, it is useful to distinguish primary from secondary or functional MR. In primary MR, there is derangement of the mitral valve itself causing left ventricular volume overload and left ventricular dysfunction. By contrast, in secondary MR, the valve and its components are typically normal and MR is related to changes of annular size (dilatation) and papillary muscle displacement due to left ventricular damage caused by myocardial infarction or dilated cardiomyopathy.In primary MR, mitral valve repair or replacement is the first-line therapy. In secondary MR, the best management includes standard medical therapy for heart failure and cardiac resynchronization therapy in selected patients. Since there is no evidence from randomized studies that surgery improves mortality, this approach may only be considered in patients who remain symptomatic despite optimal medical therapy or in patients undergoing coronary revascularization.

Transcatheter Aortic Valve Implantation

There has been significant improvement in device designs, operative techniques, and early clinical outcomes in <5 years. Presently, there are two catheter-based bioprostheses (balloon expandable or self-expandable), which have been widely used in humans and are undergoing clinical investigations. Three approaches, including transvenous, transarterial, and transapical have been used for delivery of the catheter-based bioprostheses, and transarterial and transapical approaches have been adopted by cardiologists and cardiac surgeons worldwide. The most recent clinical results have been very encouraging and promising. With experience, 30-day operative mortality with either balloon-expandable or self-expandable bioprosthesis was reduced significantly to approximately 10% in high-risk patients. In vivo long-term durability of catheter-based bioprostheses remains unknown, and presently transcatheter procedure is limited to the cohort of high-risk patients. Expanding this new technology to low-risk patients should be done with extreme caution because conventional aortic valve replacement still provides the best long-term outcome with minimal operative mortality and morbidity in low-risk patients. Ongoing clinical trials will address many unanswered questions, such as patient selection, long-term in vivo durability, preoperative assessment, and the role of the procedures in management of valvular diseases.

Comparison of the hemodynamic performance of percutaneous and surgical bioprostheses for the treatment of severe aortic stenosis

OBJECTIVES

This study was undertaken to compare the hemodynamic performance of a percutaneous bioprosthesis to that of surgically implanted (stented and stentless) bioprostheses for the treatment of severe aortic stenosis.

METHODS

Fifty patients who underwent percutaneous aortic valve implantation (PAVI) with the Cribier-Edwards or Edwards SAPIEN bioprosthetic valve (Edwards Lifesciences, Inc., Irvine, California) were matched 1:1 for sex, aortic annulus diameter, left ventricular ejection fraction, body surface area, and body mass index, with 2 groups of 50 patients who underwent surgical aortic valve replacement (SAVR) with a stented valve (Edwards Perimount Magna [SAVR-ST group]), or a stentless valve (Medtronic Freestyle, Medtronic, Minneapolis, Minnesota [SAVR-SL group]). Doppler echocardiographic data were prospectively obtained before the intervention, at discharge, and at 6- to 12-month follow-up.

RESULTS

Mean transprosthetic gradient at discharge was lower (p < 0.001) in the PAVI group (10 +/- 4 mm Hg) compared with the SAVR-ST (13 +/- 5 mm Hg) and SAVR-SL (14 +/- 6 mm Hg) groups. Aortic regurgitation (AR) occurred more frequently in the PAVI group (mild: 42%, moderate: 8%) compared with the SAVR-ST (mild: 10%, moderate: 0%) and SAVR-SL (mild: 12%, moderate: 0%) groups (p < 0.0001). At follow-up, the mean gradient in the PAVI group remained lower (p < 0.001) than that of the SAVR-ST group, but was similar to that of the SAVR-SL group. The incidence of severe prosthesis-patient mismatch was significantly lower (p = 0.007) in the PAVI group (6%) compared with the SAVR-ST (28%) and SAVR-SL (20%) groups. However, the incidence of AR remained higher (p < 0.0001) in the PAVI group compared with the 2 other groups.

CONCLUSIONS

PAVI provided superior hemodynamic performance compared with the surgical bioprostheses in terms of transprosthetic gradient and prevention of severe prosthesis-patient mismatch, but was associated with a higher incidence of AR.

Transcatheter aortic valve implantation: impact on clinical and valve-related outcomes

BACKGROUND

Transcatheter aortic valve implantation is an alternative to open heart surgery in patients with aortic stenosis. However, long-term data on a programmatic approach to aortic valve implantation remain sparse.

METHODS AND RESULTS

Transcatheter aortic valve implantation was performed in 168 patients (median age, 84 years) in the setting of severe aortic stenosis and high surgical risk. Access was transarterial (n=113) or, in the presence of small iliofemoral artery diameter, transapical (n=55). The overall success rate was 94.1% in this early experience. Intraprocedural mortality was 1.2%. Operative (30-day) mortality was 11.3%, lower in the transarterial group than the transapical group (8.0% versus 18.2%; P=0.07). Overall mortality fell from 14.3% in the initial half to 8.3% in the second half of the experience, from 12.3% to 3.6% (P=0.16) in transarterial patients and from 25% to 11.1% (P=0.30) in transapical patients. Functional class improved over the 1-year postprocedure period (P<0.001). Survival at 1 year was 74%. The bulk of late readmission and mortality was not procedure or valve related but rather was due to comorbidities. Paravalvular regurgitation was common but generally mild and remained stable at late follow-up. At a maximum of >3 years and a median of 221 days, structural valve failure was not observed.

CONCLUSIONS

Transcatheter aortic valve implantation can result in early and sustained functional improvement in high-risk aortic stenosis patients. Late outcome is determined primarily by comorbidities unrelated to aortic valve disease.

Valve implantation on the beating heart: catheter-assisted surgery for aortic stenosis

BACKGROUND

For an increasing number of patients with severe symptomatic aortic stenosis, advanced age and comorbidity make the risk of surgery unacceptably high. In such cases, catheter-based techniques for aortic valve implantation are a new therapeutic option. In this paper, we describe the initial results obtained at the German Heart Center, Munich, with a new technique of this kind.

METHODS

From June 2007 to September 2008, 152 patients underwent transcatheter aortic valve implantation at the German Heart Center, Munich (121 transfemorally, 26 transapically, and 5 through other sites of access). In this technique, a stent-mounted valve is crimped onto a catheter and then positioned and deployed in the aortic annulus under fluoroscopic control.

RESULTS

The 30-day mortality was 11.8% in this group of patients at high risk. The more common post-procedural complications were third-degree atrioventricular block leading to pacemaker implantation (31/152, 20%), vascular complications (25/152, 16%), and cerebrovascular events (8/152, 5%). Six months after the procedure, the patients had recovered clinically to a considerable extent, and the implanted prostheses exhibited good hemodynamic function.

CONCLUSIONS

The technical feasibility of catheter-based aortic valve implantation has been demonstrated at multiple centers around the world. Its indications still need to be refined on the basis of the short- and long-term results of the randomized and observational studies that are currently in progress. It is already apparent that catheter-based aortic valve implantation can bring about clinical improvement in patients who are deemed ineligible for open surgery.

Valvular regurgitation and stenosis: when is surgery required?

Valvular heart disease is a growing public health problem, with an increasing prevalence due to an ageing population. Despite advances, the medical management of symptomatic valvular heart diseases remains suboptimal, necessitating surgical correction. The challenge remains in identifying an asymptomatic or mildly symptomatic patient who will benefit from timely surgery before irreversible changes in cardiac function have occurred. The potential risks of surgery versus watchful expectancy require careful decision-making. This review is a focused update on the existing guidelines and identifies the knowledge gaps and avenues of future research in the management of patients with valvular heart diseases.

[Percutaneous treatment of aortic stenosis]

Degenerative aortic stenosis is the most frequent valvular disease in developed countries. The reference treatment is surgical valve replacement but one third of the patients are not eligible for surgery. Alternative options have been recently proposed using transcatheter valve implantation (transfemoral or trans-apical approaches) in this subset of patients. Two models of valve (balloon expandable or self-expandable) have demonstrated their efficacy and have been implanted to date in over 4000 patients worldwide. These techniques are promising but several issues remain such as the selection of patients, and the safety and durability of the devices currently used.