“Valve-in-valve” for the treatment of paravalvular leaks following transcatheter aortic valve implantation

Percutaneous paravalvular leak closure after CoreValve transcatheter aortic valve implantation using an arterio-arterial loop

Significant periprosthetic aortic regurgitation after transcatheter aortic valve implantation has become a major concern of this technique given its association with impaired survival. We report the successful closure of such defect using a vascular occlusion device with the creation of an arterio-arterial loop to gain enough support to advance the delivery sheath into de the left ventricle.

Concomitant Valve-In-Valve Transcatheter Aortic Valve Replacement and Left Ventricular Assist Device Implantation

Redo aortic valve replacement (AVR) performed simultaneously with left ventricular assist device (LVAD) implantation carries potential for increased mortality rates. Although transcatheter AVR has been used for patients with previous LVAD placement, no literature reports concomitant valve-in-valve transcatheter AVR and LVAD implantation. Our patient had severe aortic prosthetic valve deterioration and advanced heart failure. Given the risks associated with reoperative aortic valve surgery, we chose transcatheter AVR at the time of LVAD implantation. Transthoracic echocardiography results showed severe aortic prosthetic valve deterioration with moderate aortic regurgitation as well as severe left ventricular dysfunction (ejection fraction, 11%). After redosternotomy, we performed transcatheter AVR via the ascending aorta and subsequent LVAD implantation. The postoperative course was uneventful. Generally, patients with structural deterioration of a bioprosthetic valve who report for LVAD therapy present considerable challenges to the surgeon. Concomitant transcatheter AVR offers a less-invasive alternative to surgical AVR that minimizes ischemic injury to myocardium.

On the Mechanics of Transcatheter Aortic Valve Replacement

Transcatheter aortic valves (TAVs) represent the latest advances in prosthetic heart valve technology. TAVs are truly transformational as they bring the benefit of heart valve replacement to patients that would otherwise not be operated on. Nevertheless, like any new device technology, the high expectations are dampened with growing concerns arising from frequent complications that develop in patients, indicating that the technology is far from being mature. Some of the most common complications that plague current TAV devices include malpositioning, crimp-induced leaflet damage, paravalvular leak, thrombosis, conduction abnormalities and prosthesis-patient mismatch. In this article, we provide an in-depth review of the current state-of-the-art pertaining the mechanics of TAVs while highlighting various studies guiding clinicians, regulatory agencies, and next-generation device designers.

The future of transcatheter aortic valve implantation

Since the introduction of transcatheter aortic valve implantation (TAVI) into clinical practice, the treatment of aortic stenosis has changed dramatically. In the past, medical therapy with or without balloon aortic valvuloplasty was the only option for inoperable patients. More recently, TAVI has become the treatment of choice for these patients and the preferred alternative for high-risk operable patients. Surgical aortic valve replacement (SAVR) currently remains the gold standard for patients at low or intermediate operative risk. As randomized trials have demonstrated comparable results between TAVI and SAVR in the high-risk population, there is now a clear trend towards performing TAVI even in intermediate-risk patients while awaiting the results of randomized trials in that population. Nevertheless, there are still questions regarding TAVI involving paravalvular leak (PVL), stroke, pacemaker requirements, and durability that remain to be more definitively answered before TAVI can routinely be performed in a broader, lower risk population. Improvements in patient selection, imaging, and second and third generation devices have decreased the incidence of PVLs and vascular complications that followed the earliest TAVI procedures, but the rates of perioperative stroke and permanent pacemaker implantation must still be addressed. Furthermore, the long-term durability of TAVI devices and a role for post-procedure antithrombotic management remain unanswered. Until these questions are more clearly answered, it is the Heart Team's task to determine the optimal treatment for each patient based on risk scores, frailty metrics, comorbidities, patient preference, and potential for improvement in quality of life.

Post-mortem computed tomography and post-mortem computed tomography angiography following transcatheter aortic valve implantation†

OBJECTIVES

At present, transcatheter aortic valve implantation (TAVI) is widely used. As with any interventional treatment, however, TAVI may also be accompanied by complications and may result in periprocedural mortality. This study aims to evaluate such complications and causes of death after TAVI.

METHODS

The study included 32 deceased (59.4% female, n = 19, median age: 82 years) patients with TAVI, since 2008, in whom post-mortem computed tomography (PMCT) and PMCT angiography were performed with the intention of identifying complications.

RESULTS

Altogether, we registered bleeding (28.1%, 9/32), perforation and rupture (25%, 8/32), cerebral infarction (18.8%, 6/32), injury of the conduction system (3.1%, 1/32), insufficiency of the aortic (12.5%, 4/32) and the mitral valve (9.4%, 3/32) and of valve-in-valve procedures (9.4%, 3/32). Furthermore, there were findings due to cardiopulmonary resuscitation and intensive care. PMCT and PMCT angiography has advantages over autopsy. The demonstration of bleeding vessels, ruptures, the position of the implanted aortic valve and its effects on the mitral valve and its suspensions were more easily accessible by computed tomography-imaging display than by customary autopsy photo-documentation.

CONCLUSIONS

After TAVI, PMCT and PMCT angiography successfully demonstrated the complications leading to death. PMCT and PMCT angiography contribute to the post-mortem analysis of causes of periprocedural death.

Second transcatheter aortic valve implantation for treatment of suboptimal function of previously implanted prosthesis: review of the literature

OBJECTIVES

To systematically review reported cases of second transcatheter aortic valve deployment within a previously implanted prosthesis (TAV-in-TAV).

BACKGROUND

TAV-in-TAV deployment is one of the rescue strategies undertaken due to an unsuccessful or suboptimal transcatheter aortic valve implantation (TAVI) result. Currently, there are no clear indications for second valve implantation and outcomes of patients with 2 prostheses deployed remain poorly known.

METHODS

The MEDLINE and PubMed databases were searched for cases of TAV-in-TAV implantations of aortic valve.

RESULTS

Forty-three articles reporting on TAV-in-TAV deployment were included in the review. The most frequently observed indication for second valve implantation was aortic regurgitation (AR) occurring shortly after TAVI. There was a strong dominance of paravalvular over intravalvular AR, with prosthesis malposition being the main underlying cause of TAVI failure (81% of all identified cases). Perioperative echocardiographic images are crucial in identifying causes of failure and helpful in optimal rescue strategy selection. Success rate of TAV-in-TAV implantation varies from 90% to 100% with mortality rate of 0-14.3% at 30 days. Despite similar aortic valve function in follow-up, TAV-in-TAV may be an independent predictor of increased cardiovascular mortality.

CONCLUSIONS

TAV-in-TAV implantation is feasible and results in favorable short- and mid-term outcomes in patients with acute failure of TAVI without recourse to open-heart surgery. Further studies are needed to establish algorithm of the management of unsuccessful or suboptimal implantation results.

TAVI 2012: state of the art

The development of "transcatheter aortic valve implantation (TAVI)" is changing the field of cardiovascular medicine rapidly. The basic principle of TAVI is the percutaneous implantation of a bioprosthesis mounted in a metal frame. The prosthesis, which is attached to the tip of the catheter, is positioned in the native aortic valve and expanded. The first successful implantation was made by Alain Cribier in 2002. Several smaller mono- and multicenter studies later confirmed the technical feasibility of this procedure. Its true value as an important, therapeutic alternative to open heart surgery in inoperable and high-risk patients is now confirmed in large multicenter registries and by the prospective, randomized PARTNER trial. Decisive for the future acceptance of the procedure and for a possible expansion of the indication spectrum will be (1) continuous further development of the implantation technique and the prosthesis design, (2) reduction of TAVI-associated complications, (3) confirmation of the initial positive long-term results and (4) confirmation of the promising results in the treatment of surgical prosthesis dysfunctions and of patients with low to intermediate risk.

A review of most relevant complications of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has emerged for treating aortic stenosis in patients who are poor candidates for surgical aortic valve replacement. Currently, the balloon-expandable Edwards Sapien valve—which is usually implanted via a transfemoral or transapical approach—and the self-expanding CoreValve ReValving system—which is designed for retrograde application—are the most widely implanted valves worldwide. Although a promising approach for high-risk patients, the indication may be expanded to intermediate- and eventually low-risk patients in the future; however, doing so will require a better understanding of potential complications, risk factors for these complications, and strategies to individualize each patient to a different access route and a specific valve. This paper reviews the most relevant complications that may occur in patients who undergo catheter-based aortic valve implantation.

Severe Valvular Regurgitation: An Unexpected Complication During Transapical Aortic Valve Implantation Treated Successfully with the "Valve-in-Valve" Procedure

Severe symptomatic aortic stenosis (AS) in a multimorbid 77 year old female was treated with transapical aortic valve implantation with a 23 mm Edwards Sapien valve. Severe valvular regurgitation following implantation, probably due to structural valve failure, was treated successfully with a second valve-in-valve implantation. During a follow-up time of 2,5 years no further problems occurred.

Long-term outcome of patients with moderate and severe prosthetic aortic valve regurgitation after transcatheter aortic valve implantation

Recently, moderate and severe postprocedure aortic regurgitations (ARs) have been identified as independent risk factors for short- and midterm mortality after transcatheter aortic valve implantation (TAVI). However, very few data exist on the long-term outcome of postprocedure AR. From 2008 to 2011, 198 consecutive patients with severe aortic stenosis successfully underwent TAVI with the CoreValve prosthesis (Medtronic CV, Minneapolis, Minnesota). After the procedure, patients were subdivided into groups depending on the presence of moderate/severe AR. The primary study end point was death from any cause after TAVI. The secondary end point was defined as cardiovascular death. In study patients (80 ± 6 years old, logistic European System for Cardiac Operative Risk Evaluation 22 ± 16%, left ventricular ejection fraction 53 ± 13%), moderate/severe AR occurred in 28 patients (14%). Despite similar baseline characteristics, patients with moderate/severe AR had higher 30-day and 1-year mortality rates than patients with none/mild AR (21% vs 6%, p = 0.019; 57% vs 16%, p <0.001, respectively). During a mean follow-up of 535 ± 333 days, the primary end point was reached in 54 and the secondary end point in 33 patients. Moderate/severe AR was the strongest independent risk factor of all-cause-mortality (hazard ratio 4.89, 95% confidence interval 2.78 to 8.56, p <0.001) and the strongest independent risk factor of cardiovascular mortality (hazard ratio 7.90, 95% confidence interval 3.95 to 15.81, p <0.001). In conclusion, moderate and severe postprocedure ARs are not uncommon complications after TAVI. Although long-term outcome of patients with none/mild AR is favorable, outcome of patients with moderate/severe AR is dismal.

Transcatheter valve-in-valve implantation for failed balloon-expandable transcatheter aortic valves

OBJECTIVES

This study sought to evaluate outcomes after implantation of a second transcatheter heart valve (THV-in-THV) for acute THV failure.

BACKGROUND

Aortic regurgitation after transcatheter aortic valve replacement (TAVR) may be valvular due to prosthetic leaflet dysfunction or paravalvular due to poor annular sealing.

METHODS

Patients undergoing aortic balloon-expandable TAVR at 3 centers were prospectively evaluated at baseline, intraprocedurally, at hospital discharge, and annually.

RESULTS

Of 760 patients undergoing TAVR, 21 (2.8%) received a THV-in-THV implant due to acute, severe regurgitation. Aortic regurgitation was paravalvular in 18 patients and transvalvular in the remaining 3 patients. THV-in-THV implantation was technically successful in 19 patients (90%) and unsuccessful in 2 patients (10%), who subsequently underwent open heart surgery. Mortality at 30 days and 1 year was 14.3% and 24%, respectively. After successful THV-in-THV, mean aortic valve gradient fell from 37 ± 12 mm Hg to 13 ± 5 mm Hg (p < 0.01); aortic valve area increased from 0.64 ± 0.14 cm(2) to 1.55 ± 0.27 cm(2) (p < 0.01); and paravalvular aortic regurgitation was none in 4 patients, mild in 13 patients, and moderate in 2 patients. At 1-year follow-up, 1 patient had moderate and the others had mild or no paravalvular leaks. The mean transvalvular gradient was 15 ± 4 mm Hg, which was higher than in patients undergoing conventional TAVR (11 ± 4 mm Hg, p = 0.02).

CONCLUSIONS

THV-in-THV implantation is feasible and results in satisfactory short- and mid-term outcomes.

From pressure overload to volume overload: aortic regurgitation after transcatheter aortic valve implantation

Severe aortic valve stenosis is a common valvular heart disease that is characterized by left ventricular (LV) pressure overload. A lasting effect of pressure overload is LV remodeling, accompanied by concentric hypertrophy and increased myocardial stiffness. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement for patients with severe symptomatic aortic valve stenosis and high surgical risk. Although TAVI has favorable hemodynamic performance, aortic valve regurgitation (AR) is the most frequent complication because of the specific technique used for implantation of transcatheter valves. During implantation, the calcified native valve is pushed aside, and the prosthesis usually achieves only an incomplete prosthesis apposition. As a consequence, the reported prevalence of moderate and severe AR after TAVI is 6% to 21%, which is considerably higher than that after a surgical valve replacement. Although mild AR probably has minor hemodynamic effects, even moderate AR might result in serious consequences. In moderate and severe AR after TAVI, a normal-sized LV with increased myocardial stiffness has been exposed to volume overload. Because the noncompliant LV is unable to raise end-diastolic volume, the end-diastolic pressure increases, and the forward stroke volume decreases. In recent years, an increasing number of patients have successfully undergone TAVI. Despite encouraging overall results, a substantial number of patients receive neither symptomatic nor prognostic benefits from TAVI. Aortic valve regurgitation has been considered a potential contributor to morbidity and mortality after TAVI. Therefore, various strategies and improvements in valve designs are mandatory to reduce the prevalence of AR after TAVI.

Aortic annulus dimensions and leaflet calcification from contrast MSCT predict the need for balloon post-dilatation after TAVI with the Medtronic CoreValve prosthesis

AIMS

We compared the measurement of aortic leaflet calcification on contrast and non-contrast MSCT and investigated predictors of the need for balloon post-dilatation after TAVI.

METHODS AND RESULTS

In 110 patients, who had TAVI with a Medtronic CoreValve prosthesis (MCS) for symptomatic aortic stenosis, calcification of the aortic root was measured on non-contrast MSCT (conventionally) and on contrast MSCT (signal attenuation >450 Houndsfield units). Calcium volume was underestimated on contrast- when compared to non-contrast MSCT: median (IQ-range)=759 (466 to 1295) vs. 2016 (1376 to 3262) and the difference between the two methods increased with higher calcium volumes (correlation coefficient r=0.90). Calcium mass was only slightly underestimated on contrast vs. non-contrast MSCT: median (IQ-range)=441 (268 to 809) vs. 555 (341 to 950) and there was no association between the differences and increasing calcium mass (r=0.17). Balloon post-dilatation was performed for significant aortic regurgitation after TAVI in 11 of 110 patients. When compared to controls, the patients who required balloon post-dilatation had higher aortic leaflet calcium on contrast CT (p<0.01), higher aortic annulus diameters (p<0.01) and higher annulus to prosthesis area ratio (p=0.01). ROC curves demonstrated that aortic root or aortic leaflet calcium measured on either contrast- or non-contrast MSCT showed excellent discrimination for the requirement of balloon post-dilatation (area under ROC >0.80 for all), whereas the discriminatory value of aortic annulus dimensions was moderate (area under ROC=0.69) and that of prosthesis to annulus ratio was poor (area under ROC=0.36).

CONCLUSIONS

Dense aortic leaflet calcification measured on contrast MSCT discerned well the need for balloon post-dilatation after TAVI with an MCS for significant PAR. Non-contrast MSCT may no longer be needed to quantify aortic root calcium before TAVI.

Surgical Bailout Therapy after Implantation of a Medtronic CoreValve Bioprosthesis

Moderate-to-severe paraprosthesic leak causing hemodynamic deterioration and left ventricular remodeling can occur after transcatheter aortic valve implantation (TAVI). We present the case of a 75-year-old woman who underwent TAVI with a 26 mm CoreValve prosthesis complicated with an acute left ventricle dilatation due to a severe paravalvular leak. Patient was unresponsive to elective balloon post-dilatation, and therefore she was successfully treated with open-heart surgery to remove the malfunctioning CoreValve bioprosthesis and perform standard aortic valve replacement.

Predictors of moderate-to-severe paravalvular aortic regurgitation immediately after CoreValve implantation and the impact of postdilatation

OBJECTIVE

To investigate the predictors of moderate-to-severe aortic regurgitation (AR≥2+) after CoreValve implantation and evaluate the feasibility and safety of postdilatation in reducing the degree of AR.

BACKGROUND

Although transcatheter aortic valve implantation is an alternative treatment for high surgical risk patients with severe aortic stenosis, post-implantation paravalvular AR remains a complication.

METHODS

From July 2008 to July 2010, we enrolled 79 consecutive patients with severe aortic stenosis who underwent CoreValve implantation.

RESULTS

On univariable analysis, the predictors of AR≥2+ immediately after CoreValve implantation were: larger annulus size, low implantation, prosthesis mismatch, chronic renal insufficiency, a history of heart failure, and peripheral vascular disease. On multivariable analysis, the independent predictors of AR≥2+ were: larger annulus diameter (OR 1.78, 95%CI 1.25-2.55; P = 0.002), low implantation (OR 3.67, 95%CI 1.01-13.35, P = 0.05), and peripheral vascular disease (OR 3.54, 95%CI 1.19-10.56, P = 0.02). Post-CoreValve implantation, AR ≥ 2 was seen in 40.5% (32/79). Twenty-one patients underwent postdilatation with improvement in AR grade in the majority (17/21). Of the four patients who did not respond to postdilatation, two underwent valve-in-valve implantation. In one patient, the valve was pulled more proximally by the snare technique. The remaining 10 patients were treated conservatively.

CONCLUSION

The appropriate strategy for treating patients with AR≥2+ depends on the causes and severity of AR post-TAVI. This study suggests that we should carefully select the size of CoreValve prosthesis to prevent prosthesis mismatch, especially when implanted in larger annulus sizes. For valves implanted in the appropriate position, postdilatation appears effective in reducing the degree of AR.

A second prosthesis as a procedural rescue option in trans-apical aortic valve implantation

OBJECTIVE

Trans-apical aortic valve implantation (TA-AVI) using the Edwards SAPIEN™ prosthesis has evolved to a routine procedure for selected high-risk elderly patients. In rare cases, misplacement of the SAPIEN™ valve (too low a position), dysfunction of the leaflets or perforation of the interventricular septum (ventricular septal defect, VSD) occurs and requires immediate implantation of a second prosthesis within the first one. Results of this 'bailout' maneuver have not been reported yet.

METHODS

Of 305 TA-AVI procedures, 15 patients required a second prosthesis due to dysfunctional leaflets (n = 6), low position (n = 7), or VSD (n = 2). Mean age was 82.5 ± 1.3 years, mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 45.5 ± 5.4, and Society of Thoracic Surgeons (STS) Score was 13.5 ± 1.5.

RESULTS

All second SAPIEN™ valves could be implanted successfully within the first one. The second prosthesis solved leaflet dysfunction, sealed the VSD (lower position of the second prosthesis), or corrected the initial misplacement (higher position of the second prosthesis) in all patients. Within 30 days, four patients died (low cardiac output n = 3, all with preoperative ejection fraction (EF) <35%; intestinal ischemia n = 1). Intra-operative echocardiogram and angiogram revealed mild paravalvular leak in three and none/trace in 12 patients. Transvalvular gradients were low despite the implantation of the second valve (P(max)/mean 13.7 ± 4.3/6.4 ± 2.0).

CONCLUSION

Placement of a second SAPIEN™ valve is a valuable 'bailout' technique in case of VSD, dysfunctional leaflets, or too low placement of the first prosthesis. The technique leads to an excellent functional result with low transvalvular gradients. The simple, straight, tubular stent design of the SAPIEN™ prosthesis may be the ideal design for such valve-in-valve procedures.

Transcatheter valve-in-valve implantation for failing bioprosthetic valves

Transcatheter valve implantation is becoming an alternative to conventional surgical valve replacement in patients at high surgical risk. While experience and acceptance with transcatheter techniques increased rapidly, transcatheter valve implantation within failing bioprostheses has emerged as a new concept (valve-in-valve implantation). Currently, the majority of prostheses implanted in patients are bioprosthetic valves that are expected to degenerate over time. Valve-in-valve implantation provides great utility in high-operative-risk patients since the mortality risk for reoperation can be significantly higher than for first-time isolated valve replacement. Although two current devices are CE Mark approved in Europe for implantation within native valves, off-label clinical implementation of valve-in-valve have been described in numerous case reports. In this article, we provide an overview of transcatheter valve implantation in failing bioprostheses with an emphasis on the aortic position.

The next revolution: percutaneous aortic valve replacement

Aortic valve replacement (AVR) is a treatment of choice for patients with symptomatic severe aortic stenosis (AS). However, a significant proportion of these patients do not undergo surgical AVR due to high-risk features. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative for patients with severe AS who are not candidates for open-heart surgery. Since the introduction of TAVI to the medical community in 2002, there has been an explosive growth in procedures. The balloon-expandable Edwards SAPIEN valve and the self-expanding CoreValve ReValving(TM) system contribute the largest patient experience with more than 10,000 patients treated with TAVI to date. Clinical outcomes have stabilized in experienced hands, with 30-day mortality less than 10%. Careful patient selection, growing operator experience, and an integrated multidisciplinary team approach contribute to notable improvement in outcomes. In the first randomized pivotal PARTNER trial, in patients with severe AS not suitable candidates for surgical AVR, TAVI compared with standard therapy, significantly improved survival and cardiac symptoms, but was associated with higher incidence of major strokes and major vascular events. The results of randomized comparison of TAVI with AVR among high-risk patients with AS for whom surgery is a viable option are eagerly awaited to provide further evidence on the applicability of TAVI in these patients.