Shannon entropy as a reliable score to diagnose human fibroelastic degenerative mitral chords: A micro-ct ex-vivo study.

This paper is aimed at identifying by means of micro-CT the microstructural differences between normal and degenerative mitral marginal chordae tendineae. The control group is composed of 21 normal chords excised from 14 normal mitral valves from heart transplant recipients. The experimental group comprises 22 degenerative fibroelastic chords obtained at surgery from 11 pathological valves after mitral repair or replacement. In the control group the superficial endothelial cells and spongiosa layer remained intact, covering the wavy core collagen. In contrast, in the experimental group the collagen fibers were arranged as straightened thick bundles in a parallel configuration. 100 cross-sections were examined by micro-CT from each chord. Each image was randomized through the K-means machine learning algorithm and then, the global and local Shannon entropies were obtained. The optimum number of clusters, K, was estimated to maximize the differences between normal and degenerative chords in global and local Shannon entropy; the p-value after a nested ANOVA test was chosen as the parameter to be minimized. Optimum results were obtained with global Shannon entropy and 2≤K≤7, providing p < 0.01; for K=3, p = 2.86·10-3. These findings open the door to novel perioperative diagnostic methods in order to avoid or reduce postoperative mitral valve regurgitation recurrences.

Hessian analysis for the delineation of amorphous anomalies in optical coherence tomography images of the aortic wall.

The aortic aneurysm is a disease originated mainly in the media layer of the aortic wall due to the occurrence of degraded areas of altered biological composition. These anomalous regions affect the structure and strength of the aorta artery, being their occurrence and extension proportional to the arterial vessel health. Optical Coherence Tomography (OCT) is applied to obtain cross-sectional images of the artery wall. The backscattering mechanisms in tissue make aorta images difficult to analyze due to noise and strong attenuation with penetration. The morphology of anomalies in pathological specimens is also diverse with amorphous shapes and varied dimensions, being these factors strongly related with tissue degradation and the aorta physiological condition. Hessian analysis of OCT images from aortic walls is used to assess the accurate delineation of these anomalous regions. A specific metric of the Hessian determinant is used to delineate degraded regions under blurry conditions and noise. A multiscale approach, based on an anisotropic Gaussian kernel filter, is applied to highlight and aggregate all the heterogeneity present in the aortic wall. An accuracy estimator metric has been implemented to evaluate and optimize the delineation process avoiding subjectivity. Finally, a degradation quantification score has been developed to assess aorta wall condition by OCT with validation against common histology.

Identification of vessel wall degradation in ascending thoracic aortic aneurysms with OCT.

Degradation of the wall of human ascending thoracic aorta has been assessed through Optical Coherence Tomography (OCT). OCT images of the media layer of the aortic wall exhibit micro-structure degradation in case of diseased aortas from aneurysmal vessels. The OCT indicator of degradation depends on the dimension of areas of the media layer where backscattered reflectivity becomes smaller due to a disorder on the morphology of elastin, collagen and smooth muscle cells (SMCs). Efficient pre-processing of the OCT images is required to accurately extract the dimension of degraded areas after an optimized thresholding procedure. OCT results have been validated against conventional histological analysis. The OCT qualitative assessment has achieved a pair sensitivity-specificity of 100%-91.6% in low-high degradation discrimination when a threshold of 4965.88µm(2) is selected. This threshold suggests to have physiological meaning. The OCT quantitative evaluation of degradation achieves a correlation of 0.736 between the OCT indicator and the histological score. This in-vitro study can be transferred to the clinical scenario to provide an intraoperative assessment tool to guide cardiovascular surgeons in open repair interventions.

Optical coherence tomography assessment of vessel wall degradation in thoracic aortic aneurysms.

Optical coherence tomography images of human thoracic aorta from aneurysms reveal elastin disorders and smooth muscle cell alterations when visualizing the media layer of the aortic wall. These disorders can be employed as indicators for wall degradation and, therefore, become a hallmark for diagnosis of risk of aneurysm under intraoperative conditions. Two approaches are followed to evaluate this risk: the analysis of the reflectivity decay along the penetration depth and the textural analysis of a two-dimensional spatial distribution of the aortic wall backscattering. Both techniques require preprocessing stages for the identification of the air-sample interface and for the segmentation of the media layer. Results show that the alterations in the media layer of the aortic wall are better highlighted when the textural approach is considered and also agree with a semiquantitative histopathological grading that assesses the degree of wall degradation. The correlation of the co-occurrence matrix attains a sensitivity of 0.906 and specificity of 0.864 when aneurysm automatic diagnosis is evaluated with a receiver operating characteristic curve.

Structural analysis of chordae tendineae in degenerative disease of the mitral valve.

BACKGROUND: Degenerative disease of the mitral valve (DDMV) is always accompanied by lengthening and/or rupture of chordae tendineae. However, the mechanisms and the mode of chordal rupture remain controversial, and the pathologic anatomy of the apparently healthy chordae has mostly been overlooked. We analyze the structural aspects of both ruptured and intact chordae tendineae in DDMV. METHODS AND RESULTS: Structural and ultrastructural microscopic analyses indicate that both the extracellular matrix and the interstitial cells are severely affected. Degenerative chordae show alterations in the synthesis and deposition of collagen and elastin, disorganization of collagen bundles and rupture of collagen fibres, accumulation of proteoglycans and of cellular and vesicular remnants, and cell transformation into a myofibroblast phenotype. Structural disruption makes the spongiosa and the dense collagenous core separate and break. Degeneration of the chordae is segmental, affecting both chordae that are clearly abnormal, and chordae that appear healthy on visual inspection. CONCLUSIONS: Changes in both matrix synthesis and degradation disturb the ordered collagen arrangement and modify the structural and physical properties of the chordae. Progressive structural disruption of the diseased chordae is the cause of chordal rupture. Mitral surgery corrects the damage, but the underlying causes of DDMV are not corrected. Thus, progression of the disease and affectation of additional chordae may be at the basis of the late complications and the recurrent mitral regurgitation which occurs several years after surgery. Our results indicate that a more aggressive approach to surgery may be needed.

Repair of rheumatic tricuspid valve disease: predictors of very long-term mortality and reoperation.

BACKGROUND: We examined predictors of reoperation and late mortality in patients undergoing tricuspid valve repair for rheumatic disease. METHODS: Between 1997 and 2007, 299 consecutive patients (mean age 50.8 + or - 13.7 years) underwent surgical repair of the tricuspid valve for multivalvular organic rheumatic disease. A total of 184 patients was found to have mitral and tricuspid valve disease, 108 triple valve disease, 5 isolated tricuspid lesion, and 2 aortic and tricuspid valve disease. Prosthetic ring annuloplasty was performed in 78 patients, commissurotomy and ring annuloplasty in 82, isolated commissurotomy in 10, suture annuloplasty in 105, and commissurotomy and suture annuloplasty in 24. RESULTS: Thirty-day mortality was 7.4%. Previous valve surgery and reoperation for bleeding were risk factors for early death. Late mortality was 51.2%, in the majority of patients due to cardiac causes. There was a median follow-up of 16.4 years (range, 6 months to 34 years) and cumulative follow-up of 5,432 patients per year (96.7% complete). Age, New York Heart Association functional class IV and postclamping time were predictive factors for late mortality. At 25 years, the Kaplan-Meier survival was 26.6% + or - 4.2%. A total of 106 patients required valve reoperation. Age older than 40 years was a protective factor for reoperation. At 25 years, Kaplan-Meier freedom from reoperation was 35.0% + or - 5.3%. CONCLUSIONS: Repair of the tricuspid valve in patients with rheumatic valve disease can be performed with acceptable early results, but progression of rheumatic disease is associated with a high incidence of valve dysfunction and mortality in the long term.

Combined mitral and tricuspid valve repair in rheumatic valve disease: fewer reoperations with prosthetic ring annuloplasty.

BACKGROUND: We examined predictors of early and very long-term outcome after combined mitral and tricuspid valve repair for rheumatic disease. METHODS AND RESULTS: Between 1974 and 2002, 153 consecutive patients (mean age, 46.0+/-13.2 years) underwent combined mitral and tricuspid valve repair for rheumatic disease. Mitral disease was predominantly stenosis (82.3%); 100% of patients had organic tricuspid valve disease, predominantly with regurgitation (53.6%) or some degree of tricuspid stenosis (46.4%). Mitral repair included commissurotomy in 132 patients (86.3%) associated with a flexible annuloplasty in 108. Tricuspid valve repair included flexible annuloplasty in 68 patients (44.4%) and suture annuloplasty in 20 patients (13.1%) combined with tricuspid commissurotomy in 62 patients (42.5%). Thirty-day mortality was 5.9%. Late mortality was 60.1%. The median follow-up was 15.8 years (interquartile range, 6 to 19 years). Follow-up was 97.9% complete. Age>65 years was the only predictor of late mortality. Kaplan-Meier survival probability was 74.4% at 10 years and 57.0% at 15 years. Sixty-three patients required valve reoperation (mitral valve, 59; tricuspid valve, 38). Predictors of valve reoperations were either mitral or tricuspid commissurotomy without associated prosthetic ring annuloplasty. At 20 years, Kaplan-Meier freedom from reoperation was 48.5+/-5.1%. CONCLUSIONS: Combined mitral and tricuspid valve repair in rheumatic disease showed satisfactory early results. Long-term results were poor because of high mortality and a high number of valve-related reoperations. The use of prosthetic ring annuloplasty was significantly associated with a reduced incidence of both mitral and tricuspid valve reoperations.

Repeat mitral valve replacement: 30-years' experience.

Prosthetic heart valve dysfunction is an acquired condition that carries a significant risk of emergency surgery. However, the long-term natural history of the condition is not well understood. Between 1974 and 2006, 1535 isolated mitral valve replacements were performed at our hospital (in-hospital mortality 5%). In total, 369 patients needed a second operation (in-hospital mortality 8.1%), while 80 (age 59.8+/-11.4 years) needed a third. The reasons for the third intervention were structural deterioration (67.5%), paravalvular leak (20%) and endocarditis (6.3%). Some 15 patients died in hospital (18.8%). After a mean follow-up period of 17.8 years, 21 patients needed another intervention (i.e., a fourth intervention). The actuarial reoperation-free rate at 20 years was 40.1+/-13.8%. The late mortality rate was 58.5% (18-year survival rate 15.4+/-5.4%). Indications for repeat mitral valve replacement must be judged on an individual basis given the high risk associated with surgery.

Reintervenciones múltiples sobre la válvula mitral: 30 años de experiencia / Repeat mitral valve replacement: 30-years’ experience

La disfunción protésica es una enfermedad adquirida con significativo riesgo quirúrgico inmediato, aunque la historia natural a largo plazo es poco conocida. Entre 1974 y 2006 se realizaron 1.535 recambios mitrales aislados (mortalidad hospitalaria, 5%). Un total de 369 pacientes requirieron una segunda intervención (mortalidad hospitalaria, 8,1%) y 80, una tercera (59,8 ± 11,4 años). Las causas de la tercera intervención fueron deterioro estructural (67,5%), dehiscencia periprotésica (20%) y endocarditis (6,3%). La mortalidad hospitalaria fue 15 (18,8%) pacientes. Tras un seguimiento medio de 17,8 años, 21 pacientes precisaron nueva intervención (cuarta intervención) y la curva actuarial libre de reoperación fue del 40,1% ± 13,8% a 20 años. La mortalidad tardía fue del 58,5% (supervivencia a 18 años, 15,4% ± 5,4%). La indicación de una reintervención reiterativa mitral debe evaluarse de forma individualizada, dado el alto riesgo quirúrgico asociado (AU)

Prosthetic heart valve dysfunction is an acquired condition that carries a significant risk of emergency surgery. However, the long-term natural history of the condition is not well understood. Between 1974 and 2006, 1535 isolated mitral valve replacements were performed at our hospital (in-hospital mortality 5%). In total, 369 patients needed a second operation (in-hospital mortality 8.1%), while 80 (age 59.8[11.4] years) needed a third. The reasons for the third intervention were structural deterioration (67.5%), paravalvular leak (20%), and endocarditis (6.3%). Some 15 patients died in hospital (18.8%). After a mean follow-up period of 17.8 years, 21 patients needed another intervention (ie, a fourth intervention). The actuarial reoperation-free rate at 20 years was 40.1% [13.8%]. The late mortality rate was 58.5% (18-year survival rate 15.4% [5.4%]). Indications for repeat mitral valve replacement must be judged on an individual basis given the high risk associated with surgery (AU)

Surgery for rheumatic tricuspid valve disease: a 30-year experience.

OBJECTIVE: This study was undertaken to assess factors influencing short- and long-term outcomes of surgery for rheumatic disease of the tricuspid valve. METHODS: Between 1974 and 2005, a total of 328 consecutive patients (mean age 51.3 +/- 13.6 years) underwent tricuspid valve surgery for rheumatic disease. There were 12 cases of isolated tricuspid lesion, 199 of triple-valve disease, 114 of tricuspid and mitral valve disease, and 3 of aortic and tricuspid valve disease. Most patients (72%) had predominantly tricuspid regurgitation. Tricuspid valve prosthetic replacement was performed in 31 cases and valve repair in 297. RESULTS: In-hospital mortality was 7.6%. Late mortality was 52.1%, whereas the expected mortality of the Spanish population of the same age was 24.2%. Predictors of in-hospital mortality were male sex, isolated tricuspid lesion, moderate aortic insufficiency, postclamping time, and tricuspid valve replacement. Mean follow-up was 8.7 years (range 1-31 years). Follow-up was 98.9% complete. Predictors of late mortality were age, New York Heart Association functional class IV, postclamping time, and mitral valve replacement. In total, 114 patients required valve reoperation, but only 4 (3.5%) for isolated tricuspid valve dysfunction. At 30 years, actuarial survival was 12.1% +/- 4.4%, actuarial freedom from reoperation was 27.5% +/- 5.8%, and actuarial freedom from valve-related complications was 2.0% +/- 1.3%. CONCLUSION: Organic tricuspid valve disease associated with rheumatic mitral or aortic lesions increases hospital and late mortality, but valve repair compared favorably with valve replacement. Long-term results may be considered acceptable for otherwise incurable valve disease.

[Cardiac surgery in Jehovah's Witnesses. Experience in Santander, Spain]. / Cirugía cardiaca en testigos de Jehová. Experiencia en Santander.

As patients who are Jehovah's Witnesses are against blood transfusion, they are difficult to manage when a cardiac intervention is required. Between 1998 and 2004, all Jehovah's Witness patients with an indication for cardiac surgery (n=10) were operated on by the same multidisciplinary team. The mean fall in hematocrit was 30% during cardiopulmonary bypass, 35% during the postoperative period, and 22% at discharge. One patient required cardiac re-exploration because of sternal bleeding. All patients survived operation and were discharged. At follow-up, 1 patient died due to respiratory failure. Technological developments that reduce bleeding and enable lost blood to be recovered have made it possible to perform operations involving a risk of hemorrhage in Jehovah's Witnesses.

The 'Valve Racket': a new and different concept of atrioventricular valve repair.

OBJECTIVE: Mitral regurgitation due to prolapse of the mitral leaflets frequently compromises annuloplasty repair procedures. We present a new annuloplasty ring that overcomes this difficulty, preventing displacement of the leaflets into the atrium. METHODS: The 'Valve Racket' is a prosthetic ring transformed into a racket by means of handmade mesh using expanded polytetrafluoroethylene (ePTFE Gore-Tex). After transection of the marginal chordae tendineae, five sheep had the new racket implanted in the mitral (n = 3) and in the tricuspid position (n = 2). The surviving sheep underwent postoperative evaluation. RESULTS: After six months of operation, a standard transthoracic study showed competent valves without significant gradients and without residual valve regurgitation. The ring appeared encapsulated by a uniform fibrous tissue but the threads showed a completely denuded surface except in the zone proximal to the ring. Thrombi or calcification deposits in the ring, racket's mesh, or cardiac chamber were not observed. CONCLUSION: This initial experience confirmed the efficacy and simplicity of the technique.

Cirugía cardiaca en testigos de Jehová. Experiencia en Santander / Cardiac surgery in Jehovah’s witnesses. Experience in Santander, Spain

Los testigos de Jehová constituyen una población de difícil tratamiento para las intervenciones de cirugía cardiaca. Entre 1998 y 2004, todos los pacientes testigos de Jehová con indicación de cirugía cardiaca (n = 10) fueron intervenidos por un mismo equipo. El descenso medio del hematocrito fue, durante la circulación extracorpórea, del 30%, durante el postoperatorio, del 35% y en el alta, del 22%. Un paciente precisó una reintervención precoz por sangrado importante de origen esternal. Todos los pacientes fueron dados de alta y durante el seguimiento un enfermo falleció de causa respiratoria. Las medidas para disminuir y recuperar la pérdida de sangre permiten realizar intervenciones de riesgo hemorrágico en pacientes testigos de Jehová (AU)

As patients who are Jehovah's Witnesses are against blood transfusion, they are difficult to manage when a cardiac intervention is required. Between 1998 and 2004, all Jehovah's Witness patients with an indication for cardiac surgery (n=10) were operated on by the same multidisciplinary team. The mean fall in hematocrit was 30% during cardiopulmonary bypass, 35% during the postoperative period, and 22% at discharge. One patient required cardiac re-exploration because of sternal bleeding. All patients survived operation and were discharged. At follow-up, 1 patient died due to respiratory failure. Technological developments that reduce bleeding and enable lost blood to be recovered have made it possible to perform operations involving a risk of hemorrhage in Jehovah's Witnesses (AU)

Incidental in vivo detection of an isolated hemangioma of the aortic valve in a man with a history of renal transplantation.

Hemangiomas of the cardiac valves are exceptional. To our knowledge, only ten cases of valve hemangiomas, six in the mitral and four in the tricuspid valve, have been reported in the English literature. We describe an incidentally detected aortic valve hemangioma of a 62-year-old man with chronic, degenerative aortic valve stenosis, who underwent renal transplantation 7 years before. We believe that this is the first report of a hemangioma in this localization and the first one in association with solid organ transplantation. The review of the literature of the adult cases of valve hemangioma, including this report, revealed that the average age was 47.2 years (range, 24 to 68 years). No clear sex predominance has been noted. Patients can be asymptomatic or experience sudden death. Symptomatic patients have complaints of palpitations, dyspnea, or syncopal episodes. Histologically, these valve tumors are classified as capillary, cavernous, and mixed. Mean tumor size is 1.1 cm (range, 0.6 to 2 cm). In 50% of cases the hemangioma is an incidental finding at autopsy or in a removed valve. Valve aortic hemangioma, despite its rarity, should be considered in the differential diagnosis of vascular lesions of this cardiac valve.

Risk factors of prosthetic valve endocarditis: a case-control study.

BACKGROUND: Prosthetic valve endocarditis is an important cause of the morbidity and mortality associated with heart valve replacement surgery. The objective of this study was to assess risk factors of prosthetic valve endocarditis related to patients, perioperative events, and postoperative complications. METHODS: This was a retrospective case-control study conducted in a tertiary care hospital in Santander, Spain, from January 1986 to January 1998. Cases were patients with "definite" and "possible" infective endocarditis defined according to the Durack criteria. Controls were patients undergoing prosthetic valve replacement who at the time of the study had not developed infective endocarditis. Information was abstracted from medical records. Cases and controls (1:2) were matched by sex, age at operation (+/- 5 years), surgery of one or more valves in the same anatomic position, and date of operation (+/- 6 months). RESULTS: There were 81 cases and 162 controls. In the multivariate analysis, risk factors significantly associated with prosthetic valve endocarditis were functional class III or IV (New York Heart Association), alcohol consumption, prior history of endocarditis, fever in the intensive care unit, and gastrointestinal bleeding. Functional class III or IV and complications of the surgical wound were independent predictors of early infective endocarditis, whereas fever in the intensive care unit and gastrointestinal bleeding were predictors of prosthetic valve endocarditis late after operation. CONCLUSIONS: Patients with prosthetic valve endocarditis differ from people without infective endocarditis with regard to intrinsic and postoperative risk factors but not regarding perioperative-related variables.