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Survival and reoperation pattern after 20 years of experience with aortic valve–sparing root replacement in patients with tricuspid and bicuspid valves

Objective: Remodeling or reimplantation are established operative techniques of aortic valve–sparing root replacement. Long‐term follow‐up is necessary comparing tricuspid and bicuspid aortic valves. Methods: A total of 315 patients (tricuspid, n = 225, bicuspid, n = 89, quadricuspid, n = 1; remodeling, n = 101, reimplantation, n = 214) were evaluated. Mean follow‐up was 10.1 ± 5.6 and 6.4 ± 4.2 years for the remodeling and reimplantation group, respectively. Longest follow‐up was 21.9 years with 99.2% completeness. Mean age of the patients was 55.9 ± 14.3 for the remodeling group and 48.9 ± 14.5 years for the reimplantation group. Results: There was no significant difference in survival between the remodeling and reimplantation group (P = .11). Survival was comparable with the normal population in the reimplantation group (P = .33). Risk factors for late death were age, diabetes, and a greater New York Heart Association classification. Cumulative incidence of reoperation at 10 years was 5.8% for the reimplantation and 11.7% for the remodeling group (P = .65). Overall, there was no difference in the cumulative incidence of reoperation between tricuspid and bicuspid aortic valve patients (P = .13); however, a landmark analysis showed that in the second decade, the cumulative incidence of reoperation was greater in bicuspid aortic valve patients (P < .001). A total of 10 of 11 reoperated bicuspid aortic valves were degenerated. Conclusions: The remodeling and reimplantation aortic valve–sparing root replacement techniques provided excellent long‐term survival. Although the number of patients was relatively small, we provide some hints that in the second decade after the operation, especially in bicuspid aortic valve patients, the risk of reoperation may be increased, needing further evaluation.

Does Undersizing of Transcatheter Aortic Valve Bioprostheses during Valve-in-Valve Implantation Avoid Coronary Obstruction? An In Vitro Study.

Background The transcatheter aortic valve‐in‐valve implantation (TAViVI) is an evolving treatment strategy for degenerated surgical aortic valve bioprostheses (SAVBs) in patients with high operative risk. Although hemodynamics is excellent, there is some concern regarding coronary obstruction, especially in SAVB with externally mounted leaflet tissue, such as the Trifecta (St. Jude Medical Inc., St. Paul, Minnesota, United States). We investigated coronary flow and hydrodynamics before and after TAViVI in a SAVB with externally mounted leaflet tissue (St. Jude Medical, Trifecta) with an undersized transcatheter aortic valve bioprosthesis (Edwards Sapien XT; Edwards Lifesciences LLC, Irvine, California, United States) in an in vitro study. Materials and Methods An aortic root model was constructed incorporating geometric dimensions known as risk factors for coronary obstruction. Investigating the validity of this model, we primarily performed recommended TAViVI with the Sapien XT (size 26 mm) in a Trifecta (size 25 mm) in a mock circulation. Thereafter, hydrodynamic performance and coronary flow (left/right coronary diastolic flow [lCF/rCF]) after TAViVI with an undersized Sapien XT (size 23 mm) in a Trifecta (size 25 mm) were investigated at two different coronary ostia heights (COHs, 8 and 10 mm). Results Validation of the model led to significant coronary obstruction (p < 0.001). Undersized TAViVI showed no significant reduction with respect to coronary flow (lCF: COH 8 mm, 0.90‐0.87 mL/stroke; COH 10 mm, 0.89‐0.82 mL/stroke and rCF: COH 8 mm, 0.64‐0.60 mL/stroke; COH 10 mm, 0.62‐0.58 mL/stroke). Mean transvalvular gradients (4‐5 mm Hg, p < 0.001) increased significantly after TAViVI. Conclusions In our in vitro model, undersized TAViVI with the balloon‐expandable Sapien XT into a modern generation SAVB (Trifecta) successfully avoided coronary flow obstruction.

A matter of thrombosis: different thrombus-like formations in balloon-expandable transcatheter aortic valve prostheses†

OBJECTIVES Transcatheter aortic valve implantation is a treatment strategy for degenerated aortic valve prostheses, but there is some concern regarding valve thrombosis. The optimal anticoagulation strategy for implantation of a transcatheter aortic valve prosthesis remains unclear. METHODS Aortic root models with the Sapien-XT and S3 prostheses (sizes 23 and 26) fixed in a Perimount Magna Ease bioprosthesis (sizes 23 and 25) were constructed. The haemodynamics of the left ventricle were imitated in a proved in vitro model. Milk was used for coagulation after 90s. Different areas of the leaflets (W: wall coagulation, C: commissure coagulation left/right and S: sinus coagulation) were examined and the number of thrombus-like formations was counted. RESULTS A total of 54% of the thrombus-like formations were found in the sinus, 28% at the wall area, 13% at the right commissure and 10% at the left commissure. Significant differences were detected at the wall area. S3 prostheses had significantly more thrombus-like formations than the XT prostheses. Additionally, in the S3 prostheses, the thrombus-like formation resembled a film whereas in the XT prostheses, the thrombus-like formation was like the crumbs of a cake. We noted exactly the same pattern in explanted prostheses from patients. CONCLUSIONS The Sapien prostheses tend to form thromboses due to their flow properties. More than half of the thrombus-like formations were seen in the sinus. The S3 prostheses had significantly more thrombus-like formations than the XT prostheses in the wall area. There are different patterns of thrombus-like formations in XT and S3 prostheses used for transcatheter aortic valve implantation both in vivo and in vitro.

In vitro coronary flow after transcatheter aortic valve-in-valve implantation: A comparison of 2 valves

Background: Transcatheter aortic valve‐in‐valve implantation (TAVI‐ViV) is an evolving treatment strategy for degenerated surgical aortic valve bioprostheses (SAVBs). However, there is some concern regarding coronary obstruction, especially after TAVI‐ViV in calcified SAVBs with externally mounted leaflets. We investigated in vitro coronary flow and hydrodynamics after TAVI‐ViV using 2 modern SAVBs with externally and internally mounted leaflets. Methods: Aortic root models including known risk factors for coronary obstruction served for the implantation of SAVBs with either externally mounted leaflets (St Jude Trifecta, size 25) or internally mounted leaflets (Edwards Perimount Magna Ease, size 25). Left and right coronary flow, as well as hydrodynamic parameters, were measured before and after TAVI‐ViV with an Edwards Sapien XT transcatheter heart valve, size 23. After the first experimental run, the SAVB leaflets were artificially “calcified,” and the measurements were repeated. Results: In both models, noncalcified and calcified, there was no significant reduction in coronary flow with either the Trifecta or the Perimount Magna Ease SAVB. After TAVI‐ViV, in the noncalcified model, the mean pressure gradient was increased (Trifecta, P = .0001; Perimount Magna Ease, P = .006) and the geometric orifice area was decreased (P < .001 for both), whereas in the calcified model, the mean pressure gradient was decreased (P < .001 for both) and the geometric orifice area was increased (P < .001 for both). Conclusions: In our specific model, in noncalcified as well as calcified conditions, TAVI‐ViV is feasible with either SAVB (Trifecta or Perimount Magna Ease) without an increased risk of coronary obstruction. Nevertheless, before clinical application of these results, thorough preoperative assessment, considering the different limitations of this model, is mandatory.

Ex vivo hydrodynamics after central and paracommissural edge-to-edge technique: A further step toward transcatheter tricuspid repair?

Objectives: Transcatheter approaches in heart valve disease became tremendously important and are currently established in the aortic position, but transcatheter tricuspid repair is still in its beginning and remains challenging. Replicating the surgical edge‐to‐edge technique, for example, with the MitraClip System (Abbott Vascular, Santa Clara, Calif), represents a promising option and has been reported successfully in small numbers of cases. However, up to now, few data considering the edge‐to‐edge technique as a transcatheter approach are available. This study aims to determine the ex vivo hydrodynamics after the central and paracommissural edge‐to‐edge technique in different pathologies. Methods: Because of basal or apical dislocation of papillary muscles, leaflet prolapse or tethering was simulated in porcine tricuspid valves mounted on a flexible holding device. Central and paracommissural edge‐to‐edge techniques were evaluated successively in these pathologies. Regurgitant volume and mean transvalvular gradient were determined in a pulse duplicator. Results: In this ex vivo model, the isolated edge‐to‐edge technique reduced tricuspid regurgitation. In the prolapse model, regurgitant volume decreased significantly after central edge‐to‐edge technique (from 49.4 ± 13.6 mL/stroke to 39.3 ± 14.1 mL/stroke). In the tethering model, both the central and the paracommissural edge‐to‐edge techniques led to a significant decrease (from 48.7 ± 13.9 to 43.6 ± 15.6 and to 41.1 ± 13.8 mL/stroke). In all cases, the reduction of regurgitant volume was achieved at the cost of significantly increased mean transvalvular gradient. Conclusions: This study provides a reduction of tricuspid regurgitation after the edge‐to‐edge technique in the specific experimental setup. Whether this reduction is sufficient to treat tricuspid regurgitation successfully in clinical practice remains to be established. Transcatheter approaches need to be evaluated further, probably with regard to concomitant annuloplasty for higher reduction of tricuspid regurgitation.

Mitral valve replacement with the novel TRIBIO and an established stented bioprosthesis in a sheep model

OBJECTIVES Heart valve replacement with a bioprosthesis is one of the most frequently performed procedures in cardiac surgery and represents a highly effective therapy to relieve diseased heart valves. Nevertheless, as postoperatively elevated transvalvular gradients and prosthesis-patient mismatch are reported as shortcomings of the procedure or of the currently used devices, there is a need for novel bioprostheses with improved haemodynamics. This study presents preclinical haemodynamic results after mitral valve replacement with the novel TRIBIO bioprosthesis (TRIBIO) compared with an established bioprosthesis in a sheep model. METHODS Six female sheep had their mitral valves replaced with the TRIBIO and 3 with the Carpentier-Edwards Perimount, both sized 19 mm. The TRIBIO consists of a flexible valve-bearing crown, a force-decoupled interface and an intra-annular base ring. Mean and peak transvalvular gradients as well as an effective orifice area were monitored in both groups using transthoracic echocardiography over the course of the 90-day study. RESULTS In both groups, haemodynamic performance diminished over time. The TRIBIO demonstrated overall superior haemodynamics, i.e. lower transvalvular gradients and a larger effective orifice area, although the results were not statistically significant. On Day 90, the mean values for the mean and peak transvalvular gradients and the effective orifice area were 6 mmHg, 10.2 mmHg and 1.2 cm2 for the TRIBIO and 10 mmHg, 15.8 mmHg and 0.8 cm2 for the Carpentier-Edwards Perimount, respectively. CONCLUSIONS This study demonstrates a trend towards improved preclinical haemodynamic performance following mitral valve replacement with the TRIBIO compared to that with an established bioprosthesis in a sheep model.

Rest and exercise haemodynamics in patients with one of two stented bioprostheses and in healthy controls with small aortic annuli

OBJECTIVES Because bioprosthetic aortic valve replacement remains one of the most frequent cardiac surgical procedures, it is necessary to study patient haemodynamics in more detail. Until now, a few studies assessed haemodynamics during exercise, but none with special regard to small aortic annuli. We compared patients who had the differently designed bioprostheses, Trifecta and Perimount Magna Ease (PME), size ≤ 23 mm, and a healthy control group during rest and exercise. METHODS We determined the mean transvalvular gradient, the effective orifice area (EOA) and the EOA index during rest and exercise using transthoracic echocardiography in 35 patients with the Trifecta (mean age 71.4 years, follow-up 1 year, labelled valve size 21.7 mm), in 16 patients with the PME (mean age 66.2 years, follow-up 2.6 years, labelled valve size 21.6 mm) and in 25 healthy persons. The parameters derived were summarized in a simplified Valve Academic Research Consortium-2 classification to determine prosthetic valve dysfunction. RESULTS When we compared the Trifecta and the PME, a significant superiority of the Trifecta was seen at rest in mean transvalvular gradient (7.96 vs 12.19 mmHg) and EOA (1.57 vs 1.48 cm2), during exercise in all parameters (mean transvalvular gradient 11.06 vs 19.2 mmHg, EOA 1.77 vs 1.26 cm2, EOA index 0.96 vs 0.67 cm2/m2). The Trifecta showed a physiological increase in the EOA index during exercise. Exercise led to a shift to better simplified Valve Academic Research Consortium-2 categories in the Trifecta and to worse in the PME group. CONCLUSIONS This study reveals the haemodynamic superiority of the Trifecta to the PME. Especially in small aortic annuli, this difference might have some relevance for clinical and research issues.

Bicuspid aortic valve related aortopathy

Bicuspid aortic valve related aortopathy is known to significantly increase the risk for catastrophic aortic events and, therefore, represents a considerable health burden. Albeit of ongoing research in this field including genetic, molecular, hemodynamic and morphologic aspects, bicuspid aortic valve related aortopathy still represents an imperfectly understood disorder. This lack in knowledge results in a lack of consistency considering different therapeutic approaches. Recent studies have provided new insights into the etiology and clinical impacts of bicuspid aortic valve related aortopathy in different clinical settings, leading to a growing body of opinion towards a more individualized surgical approach than currently provided by the guidelines. Especially valvular hemodynamics—stenosis and regurgitation—seem to have significant impact on the development of bicuspid aortic valve related aortopathy. In this context, there is evidence that regurgitation of bicuspid aortic valves is the more fatal pathomechanism. Furthermore, “age” represents an aspect that should be taken into account when deciding whether to replace the aorta or not, because the diameter depends mainly on a patients age. The same diameter of the aorta in a 70-year old and a 20-year old patient has to be interpreted differently and should, therefore, result in different therapeutic strategies.

HeartMate III Left Ventricular Assist Device Thrombosis Triggered by an Automatic Implantable Cardioverter-Defibrillator Shock

We report the case of an HeartMate III left ventricular assist device (LVAD) thrombosis triggered by a shock from an automatic implantable cardioverter defibrillator, releasing a left ventricular thrombus sucked in the LVAD inflow cannula. With LVAD low flow only the increase in motor temperature gave a hint of the thrombosis and a computer tomography scan confirmed the diagnosis. Pump exchange was performed with an uneventful outcome.