Sovering annuloplasty rings: experimental pathology in the sheep model

Thrombocytopenia among Patients Undergoing Aortic Valve Replacement Using the Sutureless Perceval S Bioprosthesis: A Retrospective Study

BACKGROUND

The sutureless Perceval S bioprosthesis is associated with postoperative thrombocytopenia. Our objectives were to compare the incidence, severity, and clinical implications of thrombocytopenia after aortic valve replacement (AVR) using the Perceval S or the Trifecta bioprosthesis.

METHODS

Patients who underwent AVR between March 2016 and August 2019 using the Perceval or Trifecta were retrospectively included. The primary endpoint was the nadir in platelet counts within 15 days after surgery. Secondary endpoints included postoperative hemolysis and inflammatory parameters, as well as clinical and echocardiographic outcomes.

RESULTS

Overall, 156 patients were included (Perceval, n = 103; Trifecta, n = 53). Preoperatively, there was no difference in platelet counts between the two groups. Postoperatively, the Perceval S bioprosthesis was associated with a greater decrease in platelet counts. The nadir was reached at Day 3 for both groups, but thrombocytopenia was more severe for the Perceval S (Perceval S vs. Trifecta, 89.2 ± 37.7 × 109/L vs. 106.5 ± 34.1 × 109/L, p = 0.01). No difference regarding lactate dehydrogenase, C-reactive protein, and white blood cells count was found. All-cause 30-day mortality rates (both valves, 2%, p = 0.98), hospital lengths of stay, and re-operation rates were similar.

CONCLUSION

The Perceval S bioprosthesis was associated with more severe postoperative thrombocytopenia. This did not translate into higher short-term morbidity or mortality.

Risk of Stroke and Major Bleeding With Vitamin K Antagonist Use After Mitral Valve Repair

BACKGROUND

Guidelines are discordant on the use of a vitamin K antagonist (VKA) after mitral valve repair (MVr) to reduce the risk of cerebral embolic events. We performed an observational study among patients who underwent a MVr, without perioperative atrial fibrillation, to determine the risk of cerebral ischemic and major bleeding events with or without VKA.

METHODS

From 2004 to 2016, we included patients who underwent MVr, using a national administrative claims database. Those with preoperative atrial fibrillation and anticoagulant use were excluded. Patients were stratified based on the presence of a VKA. Inverse probability weighting with a Cox proportional hazard model was used.

RESULTS

After MVr, 754 patients were discharged on VKA and 1462 on no-VKA. We found no difference in the cumulative incidence for embolic stroke at 180 days (VKA: 2.21% vs no-VKA: 1.50%; hazard ratio, 1.35; P = .38). However, VKA patients had a significantly increased risk for any-cause major bleeding events at 180 days (VKA: 8.58% vs no-VKA: 4.21%; hazard ratio, 2.09; P < .001). VKA patients also had increased need for a pericardiocentesis/pericardial window at 30 days after discharge (VKA: 1.13% vs no-VKA: 0.37%; hazard ratio, 3.88; P = .025).

CONCLUSIONS

Our study suggests that VKA after MVr does not reduce the risk of cerebral embolic events but is associated with an increased risk of major bleeding events.

Clinical outcomes of tricuspid valve repair accompanying left-sided heart disease

AIM

To determine whether the need for additional tricuspid valve repair is an independent risk factor when surgery is required for a left-sided heart disease.

METHODS

One hundred and eighty patients (68 ± 12 years, 79 males) underwent tricuspid annuoplasty. Cox proportional-hazards regression model for multivariate analysis was performed for variables found significant in univariate analyses.

RESULTS

Tricuspid regurgitation etiology was functional in 154 cases (86%), organic in 16 cases (9%), and mixed in 10 cases (6%), respectively. Postoperative mortality at 30 days was 11.7%. Mean follow-up was 51.7 mo with survival at 5 years of 73.5%. Risk factors for mortality were acute endocarditis [hazard ratio (HR) = 9.22 (95%CI: 2.87-29.62), P < 0.001], ischemic heart disease requiring myocardial revascularization [HR = 2.79 (1.26-6.20), P = 0.012], and aortic valve stenosis [HR = 2.6 (1.15-5.85), P = 0.021]. Significant predictive factors from univariate analyses were double-valve replacement combined with tricuspid annuloplasty [HR = 2.21 (1.11-4.39), P = 0.003] and preoperatively impaired ejection fraction [HR = 1.98 (1.04-3.92), P = 0.044]. However, successful mitral valve repair showed a protective effect [HR = 0.32 (0.10-0.98), P = 0.046]. Additionally, in instances where tricuspid regurgitation required the need for concomitant tricuspid valve repair, mortality predictor scores such as Euroscore 2 could be shortened to a simple Euroscore-tricuspid comprised of only 7 inputs. The explanation may lie in the fact that significant tricuspid regurgitation following left-sided heart disease represents an independent risk factor encompassing several other factors such as pulmonary arterial hypertension and dyspnea.

CONCLUSION

Tricuspid annuloplasty should be used more often as a concomitant procedure in the presence of relevant tricuspid regurgitation, although it usually reveals an overly delayed correction of a left-sided heart disease.

Biocompatibility and Systemic Safety of a Novel Implantable Annuloplasty Ring for the Treatment of Mitral Regurgitation in a Minipig Model

Prosthetic annuloplasty rings are a common treatment modality for mitral regurgitation, and recently, percutaneous implantation techniques have gained popularity due to their favorable safety profile. Although in common use, biocompatibility of annuloplasty rings has been reported only sparsely in the literature, and none of these reports used the percutaneous technique of implantation. We report on the biocompatibility and the systemic safety of a novel transcatheter mitral valve annuloplasty ring (AMEND™) in 6 minipigs. This device is composed of a nitinol tube surrounded by a braided polyethylene terephthalate fabric tube. The device produced no adverse inflammatory response, showing gradual integration between the metal ring and the fabric by normal host fibrocellular response, leading to complete neoendocardium coverage. There was no evidence for adverse reactions, rejection, or intolerance in the valvular structure. In 2 animals, hemopericardium resulted from the implantation procedure, leading to right-sided cardiac insufficiency with pulmonary edema and liver congestion. The findings reported herein can serve as a case study for the expected healing pathology reactions after implantation of transcatheter mitral valve annuloplasty rings.

Efficacy of polymer injection for ischemic mitral regurgitation: persistent reduction of mitral regurgitation and attenuation of left ventricular remodeling

OBJECTIVES

The aim of this study was to examine the chronic effects of polyvinyl-alcohol (PVA) injection on mitral regurgitation (MR) reduction, mitral valve geometry, and left ventricular (LV) remodeling in a chronic ischemic MR sheep model.

BACKGROUND

Previous studies have demonstrated acute efficacy of PVA hydrogel polymer injection into infarcted myocardium underlying the papillary muscle to relieve MR by papillary muscle repositioning. However, the chronic efficacy of PVA injection in the chronic infarction setting remains unclear.

METHODS

Sixteen sheep developed chronic MR 8 weeks after induced inferoposterior myocardial infarction. Ten consecutive sheep underwent PVA injection (PVA group) and 6 sheep served as control subjects with saline injection. Epicardial 2-/3-dimensional echocardiography was performed at the baseline, chronic MR (pre-injection), and sacrifice (8 weeks after injection) stages.

RESULTS

Both groups were comparable at the baseline and chronic MR stages. At sacrifice, MR decreased from moderate to trace or mild (vena contracta: 0.17 ± 0.08 cm vs. 0.56 ± 0.10 cm, p < 0.001) in the PVA group but progressed to moderate to severe in the control group. End-systolic and -diastolic volumes remained stable in the PVA group but increased significantly in the control group (both p < 0.05). At sacrifice, compared with the control group, the PVA group had significantly less left ventricular remodeling (end-systolic volume: 41.1 ± 10.4 ml vs. 55.9 ± 12.4 ml, p < 0.05), lower MR severity (vena contracta: 0.17 ± 0.08 cm vs. 0.60 ± 0.14 cm, p < 0.01), and favorable changes in mitral valve geometry.

CONCLUSIONS

Polymer injection in a chronic ischemic MR model results in persistent reduction of MR and attenuation of continued left ventricular remodeling over 8 weeks of follow-up.

Comparison of the novel Medtentia double helix mitral annuloplasty system with the Carpentier-Edwards Physio annuloplasty ring: morphological and functional long-term outcome in a mitral valve insufficiency sheep model

Background

The prevalence of mitral regurgitation in cardiac diseases requires annuloplasty systems that can be implanted without excessive patient burden. This study was designed to examine the morphological and functional outcome of a new double helix mitral annuloplasty ring in an ovine model in comparison to the classical Carpentier-Edwards (CE) annuloplasty ring as measured by reduction of mitral regurgitation and tissue integration. The Medtentia annuloplasty ring (MAR) is a helical device that is rotated into the annulus self-restoring the valve geometry, enabling a faster fixation without the need of elaborate repair of the valve geometry. The ventricular part of the helical ring encircles the valve chords.

Methods

Twenty adult sheep were overpaced until 2+ level mitral valve regurgitation was achieved. Seven animals per group received either the MAR or the CE ring. Implantation was performed on-pump in a beating heart through the left atrial appendix. The animals were sacrificed 3.6 ± 0.3 months after surgery following an echocardiography for assessing mitral regurgitation as primary endpoint. The annuloplasty rings with surrounding tissue were harvested for histological analyses as secondary endpoints. The remaining six sheep received the MAR system and were sampled seven, nine or 12 months after surgery.

Results

Implantation time (p < 0.01) and perfusion time (p < 0.001) as clinical secondary endpoints were significantly shorter in the MAR group. Echocardiography follow-ups showed sufficient valve function repair in nearly all animals with a normalization of the ventricle diameters in both groups (group difference: p = 0.147). The weights of the hearts did not differ significantly. Histology revealed adequately covered atrial annuloplasty rings with functional endothelium and lack of excessive granulation tissue or fibrosis in all specimens. The ventricular projections of the MAR systems encircling the chordae tendineae were not completely covered with neointimal tissue, although in no case were microthrombi detected and no thromboembolic events were recorded.

Conclusions

The new MAR system is an easy to use annuloplasty system with a functional outcome comparable to that of the well–proven CE ring. Mitral valve regurgitation is effectively stopped both by restricting the pathological expansion of the annulus and by gathering the chords without thrombus formation.

Beating Heart Mitral Valve Replacement with a Bovine Pericardial Bioprosthesis for Treatment of Mitral Valve Dysplasia in a Bull Terrier

OBJECTIVES

To describe an open, beating heart surgical technique and use of a bovine pericardial prosthetic valve for mitral valve replacement (MVR) in the dog.

STUDY DESIGN

Clinical case report.

ANIMALS

Male Bull Terrier (17-month-old, 26 kg) with mitral valve dysplasia and severe regurgitation.

METHODS

A bovine pericardial bioprosthesis was used to replace the mitral valve using an open beating heart surgical technique and cardiopulmonary bypass.

RESULTS

Successful MVR was achieved using a beating heart technique. Mitral regurgitation resolved and cardiac performances improved (left ventricular end-diastolic diameter decreased from 57.6 to 48.7 mm, and left atrium/aorta ratio returned to almost normal, from 1.62 to 1.19). Cardiopulmonary by-pass time and total surgical duration were decreased compared with standard cardioplegic techniques. Surgical recovery was uneventful and on echocardiography 6 months later valve function was excellent.

CONCLUSION

Considering the technique advantages (no cardiac arrest, ischemic reperfusion injury, and hypothermia, or the need for aortic dissection and cannulation for administration of cardioplegic solution), short-term mortality and morbidity may be reduced compared with standard cardioplegic techniques.

CLINICAL RELEVANCE

Based on experience in this dog, beating heart mitral valvular replacement is a seemingly safe and viable option for the dog and bovine pericardial prosthesis may provide better long-term survival than mechanical prostheses.