New insights and novel perspectives in bileaflet mechanical heart valve prostheses thromboresistance.

BACKGROUND: Although well-known for their thromboresistance, bileaflet mechanical heart valves (BMHV) require lifelong anti-thrombotic therapy. This must be associated with a certain level of thrombogenicity. Since both thromboresistance and thrombogenicity are explained by the blood-artificial surface or liquid-solid interactions, the aim of the present study was to explore BMHV thromboresistance from new perspectives. The wettability of BMHV pyrolytic carbon (PyC) occluders was investigated in under-liquid conditions. The submerged BMHV wettability clarifies the mechanisms involved in the thromboresistance. METHODS: The PyC occluders of a SJM Regent™ BMHV were previously laser irradiated, to create a surface hierarchical nano-texture, featuring three nano-configurations. Additionally, four PyC occluders of standard BMHV (Carbomedics, SJM Regent™, Bicarbon™, On-X®), were investigated. All occluders were evaluated in under-liquid configuration, with silicon oil used as the working droplet, while water, simulating blood, was used as the surrounding liquid. The under-liquid droplet-substrate wetting interactions were analyzed using contact angle goniometry. RESULTS: All the standard occluders showed very low contact angle, reflecting a pronounced affinity for non-polar molecules. No receding of the contact line could be observed for the untreated occluders. The smallest static contact angle of around 61° could be observed for On-X® valve (the only valve made of full PyC). The laser-treated occluders strongly repelled oil in underwater conditions. A drastic change in their wetting behaviour was observed depending on the surrounding fluid, displaying a hydrophobic behaviour in the presence of air (as the surrounding medium), and showing instead a hydrophilic nature, when surrounded by water. CONCLUSIONS: BMHV "fear" water and blood. The intrinsic affinity of BMHV for nonpolar fluids can be translated into a tendency to repel polar fluids, such as water and blood. The blood-artificial surface interaction in BMHV is minimized. The contact between blood and BMHV surface is drastically reduced by polar-nonpolar Van der Waals forces. The "hydro/bloodphobia" of BMHV is intrinsically related to their chemical composition and their surface energy, thus their material: PyC indeed. Pertaining to thromboresistance, the surface roughness does not play a significant role. Instead, the thromboresistance of BMHV lies in molecular interactions. BMHV wettability can be tuned by altering the surface interface, by means of nanotechnology.

Contained rupture of a sinus of Valsalva aneurysm: Is it just a matter of luck?

BACKGROUND: Contained rupture of the ascending aorta is a rare condition, but the severity of this complication enforces strict guidelines for its prevention and a prompt diagnosis, once already occurred. CASE PRESENTATION: A 66-year-old man with a history of type 2 diabetes, longstanding aortic valve stenosis and aortic root aneurysm of 47 mm was hospital admitted for elective surgery. A Bentall-De Bono procedure was performed in order to replace the stenotic bicuspid aortic valve and exclude the dilated portion of the aortic wall. Intraoperatively, a discontinuity of the aortic wall, just above the aortic annulus, at the non-coronary sinus of Valsalva was incidentally observed. The aortic wall discontinuity was none other than a contained aortic rupture. The preoperative CT-scan images were afterwards analyzed by the radiologist, in order to identify the contained aortic rupture. Indeed a false aneurysm of the non-coronary sinus of Valsalva of a maximum diameter of 15 mm was detected, thanks to a 3D reconstruction. CONCLUSIONS: The diagnosis of contained aortic rupture is certainly demanding, particularly in absence of signs or symptoms of rupture in a chamber of the heart or in the pericardium. Although this case represents a consensus of experts' opinion, the recognition of these specific cases in which the risk of dissection, rupture or death is at its highest, would allow to operate at the appropriate time, improving the outcomes.

Laser texturing of a St. Jude Medical RegentTM mechanical heart valve prosthesis: the proof of concept.

OBJECTIVES: The liquid-solid interactions have attracted broad interest since solid surfaces can either repel or attract fluids, configuring a wide spectrum of wetting states (from superhydrophilicity to superhydrophobicity). Since the blood-artificial surface interaction of bileaflet mechanical heart valves essentially represents a liquid-solid interaction, we analysed the thrombogenicity of mechanical heart valve prostheses from innovative perspectives. The aim of the present study was to modify the surface wettability of standard St. Jude Medical Regent™ occluders. METHODS: Four pyrolytic carbon occluders were irradiated by means of ultra-short pulse laser, to create 4 different nanotextures (A-D), the essential prerequisite to achieve superhydrophobicity. The static surface wettability of the occluders was qualified by the contact angle (θ) of 2 µl of purified water, using the sessile drop technique. The angle formed between the liquid-solid and the liquid-vapour interface was the contact angle and was obtained by analysing the droplet images captured by a camera. The morphology of the occluders was characterized and analysed by a scanning electron microscope at different magnifications. RESULTS: The scanning electron microscope analysis of the textures revealed 2 different configurations of the pillars since A and B showed well-rounded shaped tops and C and D flat tops. The measured highest contact angles were comprised between 108.1° and 112.7°, reflecting an improved hydrophobicity of the occluders. All the textures exhibited, to different extents, an orientation (horizontal or vertical), which was strictly related to the observed anisotropy. CONCLUSIONS: In this very early phase of our research, we were able to demonstrate that the intrinsic wettability of pyrolytic carbon occluders can be permanently modified, increasing the water repellency.

Minimally Invasive Aortic Valve Replacement with Sutureless Valves: Results From an International Prospective Registry.

OBJECTIVE: To report the early and mid-term results of patients who underwent minimally invasive aortic valve replacement (MI-AVR) with a sutureless prosthesis from an international prospective registry. METHODS: Between March 2011 and September 2018, among 957 patients included in the prospective observational SURE-AVR (Sorin Universal REgistry on Aortic Valve Replacement) registry, 480 patients underwent MI-AVR with self-expandable Perceval aortic bioprosthesis (LivaNova PLC, London, UK) in 29 international institutions through either minithoracotomy (n = 266) or ministernotomy (n = 214). Postoperative, follow-up, and echocardiographic outcomes were analyzed for all patients. RESULTS: Patient age was 76.1 ± 7.1 years; 64.4% were female. Median EuroSCORE I was 7.9% (interquartile range [IQR], 4.8 to 10.9). Median cardiopulmonary bypass and cross-clamp times were 81 minutes (IQR 64 to 100) and 51 minutes (IQR 40 to 63). First successful implantation was achieved in 97.9% of cases. Two in-hospital deaths occurred, 1 for noncardiovascular causes and 1 following a disabling stroke. In the early (≤30 days) period, stroke rate was 1.4%. Three early explants were reported: 2 due to nonstructural valve dysfunction (NSVD) and 1 for malpositioning. One mild and 1 moderate paravalvular leak were reported. In 16 patients (3.3%) pacemaker implantation was needed. Mean follow-up was 2.4 years (maximum = 7 years). During follow-up 5 explants were reported, 3 due to endocarditis and 2 due to NSVD. Follow-up stroke rate was 2.5%. Three structural valve deteriorations not requiring reintervention were reported. Five-year survival was 91.45%. CONCLUSIONS: In this large prospective international registry, MI-AVR with Perceval valve confirmed to be safe, reproducible, and effective in an intermediate-risk population, providing excellent clinical recovery both in early and mid-term follow-up.

Catching a floating thrombus; a case report on the treatment of a large thrombus in the ascending aorta.

BACKGROUND: The ascending aorta is an uncommon site for non-infective thrombus. In non-aneurysmal and non-atherosclerotic vessels this condition becomes extremely rare, while it represents a source of potential cerebral and peripheral embolic events. Currently, there is no consensus in the guidelines on how to treat a free floating thrombus in ascending aorta, therefore we present our decision making process and therapeutic strategy. CASE PRESENTATION: A healthy 48-year-old man was hospital admitted with acute abdominal pain. CT-scan showed a right renal embolism in presence of a defect in the distal ascending aorta suggestive for thrombus. After heart team discussion the patient was scheduled for surgery and successfully underwent an emergent thrombus removal. Also, owing to multiple aortic wall insertions, the ascending aorta was replaced. The patient's recovery was uneventful and histological examination showed no signs of connective tissue disorders of aortic wall while confirmed the thrombotic nature of the mass. CONCLUSIONS: We present a patient with a floating thrombus in the ascending aorta who underwent an ascending aorta replacement. While angio-CT scan led to a prompt diagnosis, intraoperative epi-aortic echocardiography allowed to define precise location of thrombus, minimizing operative risk. This case demonstrates that multi-disciplinary heart team discussion is essential to define a successful strategy, that surgical treatment is feasible with specific tools such as epi-aortic echocardiography.

Clinical mid-term results after tricuspid valve replacement.

Tricuspid valve replacement (TVR) is associated with high mortality and morbidity. Frequently, TVR is performed in critically ill patients with high frequency of re-intervention. We analyzed our experience in TVR focusing on predicting risk factors, mid-term survival and quality of life assessed with a Short-Form 36 Health Survey (SF-36) questionnaire. Between January 1992 and May 2007, 81 consecutive patients underwent TVR (54 re-interventions, 66.7%; 46 procedures, associated with a left-sided operation, 56.8%). There were 59 females (73%) with a mean age of 59.3+/-11.6 years. The most prevalent etiology was rheumatic fever (61.7%). Pulmonary hypertension was present in 64%. Mean left ventricle ejection fraction (LVEF) was 56.6% and mean right ventricle ejection fraction (RVEF) was 48.1%. All but four patients (4.9%) received a bio-prosthesis. Hospital mortality was 9.88%. The mean follow-up was 61+/-42 months. Survival was 68% at five years. Univariate predictors of hospital mortality were atrial fibrillation (AFib) (P<0.01), associated procedures on the left heart (P=0.025) and preoperative chronic right heart failure symptoms (P<0.01). At follow-up: 10.8% of patients had a pace-maker (PM) induced rhythm; the mean SF-36 score was 51.1+/-4.8 (range 59-38). Age (P=0.015), associated procedures (P=0.024) and previous cardiovascular surgery (P=0.015) were univariate predictors of the SF-36 score. At a multivariate analysis LVEF, venous congestion and pulmonary artery pressures (PAPs) were related with a SF-36 score.

"Grey zone" patterns of unexplained endocarditis: still a challenge for clinical decision making.

The authors report two cases of unexplained active inflammatory endocarditis with totally different clinical presentations. The patients had undergone previous mitral repair surgery and were referred for multiple soft mobile masses on the mitral ring without clinical or laboratory signs of endocarditis. Serologic screening and blood culture results were negative, including those for specific fastidious bacteria, as well as immunologic tests to rule out "nonbacterial thrombotic endocarditis." Before new surgery, both patients were treated with long-term antibiotic and anticoagulant therapy, with no significant changes in clinical setting and echocardiographic patterns. In neither case was it possible to characterize a specific microorganism: the intraoperative findings were highly evocative of active endocarditis with a macroscopic infiltration of the mitral ring, and culture results from surgical material and valvular tissue were negative.

Quality of life of elderly patients following valve surgery for chronic organic mitral regurgitation.

OBJECTIVE: Mitral valve surgery for organic mitral regurgitation (MR) in the elderly has been debated. In the elderly, quality of life is a better indicator of surgical success than survival. We assessed quality of life of elderly patients submitted to surgery for MR using the Minnesota Living with Heart Failure (MLHF) questionnaire. METHODS: Between August 2003 and August 2006, 225 consecutive patients >70 years old underwent surgical treatment of organic MR. Mean age was 77 +/- 3.3 years (range 71-87 years). Mean EF was 50 +/- 11%. Degenerative disease was the most prevalent (77%) etiology. CABG was associated in 25% of patients. Mean Charlson score was 4.3 +/- 1.5 and 101 patients (45%) were NYHA class III and IV. Hospital survivors were followed up and quality of life by MLHF score was assessed. RESULTS: Mitral repair and replacement were equally distributed in this population. Hospital mortality was 2.7%. Late survival was 91 +/- 1.9% at 3 years. MLHF was obtained from 204 patients at mean 2 +/- 1 years of follow-up. MLHF score was 38 +/- 18; there were 135 (66%) patients with MLHF >30. MLHF tended to increase with age at follow-up (p = 0.007). Multivariable predictors of MLHF were preoperative atrial fibrillation (p = 0.019), diabetes (p = 0.03), higher creatinine level (p = 0.0009), higher EuroSCORE (p = 0.02), residual mitral regurgitation grade at follow-up echocardiography (p < 0.0001) and systolic pulmonary artery pressure at follow-up (p = 0.04). Type of surgical treatment (repair vs replacement and choice of prosthesis) did not predict MLHF at follow-up, although those who had recurrent MR after repair had the highest scores compared to patients who had repair and durable result and those treated by replacement (MLHF was 51 +/- 21, vs 34 +/- 16, vs 39 +/- 18, respectively, p = 0.0013). CONCLUSIONS: Quality of life following mitral valve surgery is suboptimal in more than half of elderly patients. MLHF score at follow-up is mostly related to preoperative conditions. Type of surgery does not influence MLHF score, however, quality of life is worse in patients with recurrent/residual MR following repair.

Annular-to-leaflet mismatch and the need for reductive annuloplasty in patients undergoing mitral repair for chronic mitral regurgitation due to mitral valve prolapse.

Annular dilation is a common feature of chronic degenerative mitral regurgitation caused by leaflet prolapse. Accordingly, patients undergoing surgical repair usually undergo concomitant reductive annuloplasty to restore a normal annular-to-leaflet relation. With the evolution of transcatheter valve repair technologies, patient selection criteria for those who do not require annuloplasty are needed. A series of patients undergoing mitral repair was analyzed, and the role of annular-to-leaflet mismatch in identifying patients requiring reductive annuloplasty was explored. Preoperative data for 82 patients undergoing mitral repair with annuloplasty for degenerative mitral regurgitation were prospectively collected, including annular intercommissural (IC) and septolateral (SL) dimensions and heights of anterior (ALH) and posterior leaflets. An SL/ALH ratio >1.4 was used to define annular-to-leaflet mismatch. After mitral repair, the ratio between preoperative IC distance and the size of the implanted annular prosthesis (Seguin ring [SR], IC/SR <1.2) was used to identify patients for whom annuloplasty was nonreductive. All patients underwent successful mitral repair. Mean preoperative IC was 46 +/- 6 mm, SL was 42 +/- 5 mm, and ALH was 31 +/- 5 mm. Mean SR was 34 +/- 3 mm, with a mean IC/SR ratio of 1.34 +/- 0.14. Sixteen patients (19%) had an IC/SR ratio <1.2. IC/SR ratio <1.2 was predicted by a SL/ALH ratio < or =1.4 (p = 0.009). In conclusion, annular dilation is negligible in <20% of surgical candidates. In this subgroup, an isolated leaflet repair may be indicated. SL/ALH ratio is a good indicator of annular-to-leaflet mismatch and could be used as an adjunct to other methods of annular function assessment to select patients for ringless mitral repair.

Surgical isolated edge-to-edge mitral valve repair without annuloplasty: clinical proof of the principle for an endovascular approach.

AIMS: A variety of endovascular technologies for valve repair for mitral regurgitation (MR) are under development. Endovascular Edge-to-Edge (E2E) approach recently entered the clinical trial phase. The aim of the present study was to determine the effectiveness of surgical isolated E2E repair without annuloplasty to predict the efficacy of the endovascular E2E approach. METHODS AND RESULTS: Clinical and echocardiographic data of 29 patients with either degenerative or functional MR who had surgical E2E repair without annuloplasty, were retrospectively analysed. Mean age was 63.8+/-8.79 years, 45% were in NYHA class III or IV and 41% had a left ventricular ejection fraction less than 60%. Hospital mortality was 3.4% and overall survival after a mean follow-up of 6.8 year was 93%. At latest follow-up, 68% of patients were in NYHA class I, 28% in class II and 4% in class III; 86% of patients had MR < grade 2. Two patients with recurrent grade 4 MR underwent re-operation. The 5 years freedom from the combined end-point of recurrent MR>2+ and re-operation, was 90+/-5%. CONCLUSIONS: Isolated surgical E2E mitral repair, intentionally performed without annuloplasty, has acceptable midterm results for degenerative and functional MR, comparable to conventional repair techniques with annuloplasty. These results encourage the evaluation of less invasive endovascular E2E repair approaches in a clinical setting.