Bridging transitions and capillary forces for colloids in a slit.

Capillary bridges can form between colloids immersed in a two-phase fluid, e.g., in a binary liquid mixture, if the surface of the colloids prefers the species other than the one favored in the bulk liquid. Here, we study the formation of liquid bridges induced by confining colloids to a slit, with the slit walls having a preference opposite to the one of the colloid surface. Using mean field theory, we show that there is a line of first-order phase transitions between the bridge and the no-bridge states, which ends at a critical point. By decreasing the slit width, this critical point is shifted toward smaller separations between the colloids. However, at very small separations and far from criticality, we observe only a minor influence of the slit width on the location of the transition. Monte Carlo simulations of the Ising model, which mimics incompressible binary liquid mixtures, confirm the occurrence of the bridging transitions, as manifested by the appearance of "spinodal" regions where both bridge and no-bridge configurations are stable or metastable. Interestingly, we find that there is no such spinodal region in the case of small colloids, but we observe a sharpening of the transition when the colloid size increases. In addition, we demonstrate that the capillary force acting between the colloids can depend sensitively on the slit width and varies drastically with temperature, thus achieving strengths orders of magnitude higher than at criticality of the fluid.

Transpulmonary correction of an isolated aortopulmonary window in an adult.

We describe the operative management of a 65-year-old patient with a congenital type I aortopulmonary window. At surgery, heavy calcifications on the aortic side of the defect, and close proximity with the left coronary ostium, prevented patch repair from the transaortic access. Patch closure through a combined transpulmonary approach was therefore required. This case illustrates unique features of a late-presenting aortopulmonary window.

Cardiac valvular surgery and history of anorectic drug intake: A retrospective study of a large population of benfluorex-exposed patients.

BACKGROUND: Anorectic drugs are overlooked as a cause of valvular heart disease (VHD). AIM: To describe the characteristics of a large population of patients with severe VHD who underwent cardiac surgery and had a history of benfluorex intake. METHODS: Retrospective observational and cross-sectional study of patients from a large French database (Office National d'Indemnisation des Accidents Médicaux). Clinical, echocardiographic, surgical and pathology findings were comprehensively collected from medical files. RESULTS: From a chart review of 9584 subjects, 1031 patients with VHD underwent cardiac surgery; 453 surgical patients were excluded because of VHD obviously unrelated to benfluorex exposure, six because of missing data and eight declined to participate. The final study population comprised 564 patients who had surgery between 1987 and 2019. Median age was 58 (interquartile range 50-65) years; 85% were female. Median duration of preoperative benfluorex exposure was 5.8 (3.3-10) years. Most patients had aortic and mitral valve disease. Pure or predominant aortic and/or mitral regurgitation were found in 84% of patients (n=471), and aortic or mitral stenosis (pure or combined with regurgitation) in 12% (n=67) and 15% (n=84), respectively. Overall, 403 aortic, 402 mitral and 64 tricuspid valve surgical procedures were collected. Aortic and mitral valves were found to be thickened, rigid and/or restrictive in most cases; restrictive tricuspid valve disease was seldom documented. Pathology was available in half of the population (276 patients); valvular fibrosis suggestive of drug-induced VHD was found in 222 patients, including 146 with expert examination. Mixed VHD aetiologies were discussed in 107 patients, including 54 with available pathology. CONCLUSIONS: Drug-induced VHD features are miscellaneous, including well-known restrictive valvular regurgitation, but also stenosis or combined regurgitation and stenosis. Besides a history of drug taking, thorough echocardiography and comprehensive surgical reports, pathology is key in the diagnostic procedure.

Survival in patients with idiopathic, familial, and anorexigen-associated pulmonary arterial hypertension in the modern management era.

BACKGROUND: Novel therapies have recently become available for pulmonary arterial hypertension. We conducted a study to characterize mortality in a multicenter prospective cohort of patients diagnosed with idiopathic, familial, or anorexigen-associated pulmonary arterial hypertension in the modern management era. METHODS AND RESULTS: Between October 2002 and October 2003, 354 consecutive adult patients with idiopathic, familial, or anorexigen-associated pulmonary arterial hypertension (56 incident and 298 prevalent cases) were prospectively enrolled. Patients were followed up for 3 years, and survival rates were analyzed. For incident cases, estimated survival (95% confidence intervals [CIs]) at 1, 2, and 3 years was 85.7% (95% CI, 76.5 to 94.9), 69.6% (95% CI, 57.6 to 81.6), and 54.9% (95% CI, 41.8 to 68.0), respectively. In a combined analysis population (incident patients and prevalent patients diagnosed within 3 years before study entry; n=190), 1-, 2-, and 3-year survival estimates were 82.9% (95% CI, 72.4 to 95.0), 67.1% (95% CI, 57.1 to 78.8), and 58.2% (95% CI, 49.0 to 69.3), respectively. Individual survival analysis identified the following as significantly and positively associated with survival: female gender, New York Heart Association functional class I/II, greater 6-minute walk distance, lower right atrial pressure, and higher cardiac output. Multivariable analysis showed that being female, having a greater 6-minute walk distance, and exhibiting higher cardiac output were jointly significantly associated with improved survival. CONCLUSIONS: In the modern management era, idiopathic, familial, and anorexigen-associated pulmonary arterial hypertension remains a progressive, fatal disease. Mortality is most closely associated with male gender, right ventricular hemodynamic function, and exercise limitation.

Argument for a Doppler echocardiography during exercise in assessing asymptomatic patients with severe aortic stenosis.

AIMS: Exercise stress testing (EST) is recommended by guidelines to risk-stratify patients with asymptomatic valvular aortic stenosis (AS), though the role of quantitative exercise-Doppler echocardiography has rarely been studied. This prospective study sought to correlate standard EST results with the haemodynamic measurements made during exercise by Doppler echocardiography. METHODS AND RESULTS: We performed rest and semi-supine exercise Doppler echocardiography in 44 consecutive patients (mean age=68+/-12 years) with aortic valve areas

Prolonged heparin and vitamin K antagonist regimen for early non-obstructive thrombosis of mechanical mitral valve prostheses.

BACKGROUND AND AIM OF THE STUDY: Transesophageal echocardiography (TEE) has been used to document the incidence of non-obstructive thrombosis (NOT) after mechanical prosthetic mitral valve replacement (MVR). The postoperative occurrence and unpredictable evolution of NOT complicate its management. The study aim was to examine the safety and efficacy of prolonged, combined administration of heparin and vitamin K antagonists (VKA) recommended for this indication. METHODS: All patients who underwent mechanical prosthetic MVR between July 1999 and December 2004 at the authors' institution were systematically studied with TEE immediately after surgery. Patients who presented with > or = 5 mm NOT were treated with combined heparin and VKA until TEE-confirmed resolution of the thrombus. RESULTS: Among 256 patients who underwent 263 MVRs (seven reinterventions), 47 (17.9%) presenting with > or = 5 mm NOT received combined heparin and VKA for between 7 and 115 days (median 17 days). No thromboembolic or hemorrhagic events or deaths were observed during this period of observation. Four patients were treated with danaparoid and VKA because of thrombocytopenia induced by heparin before the diagnosis of NOT. Over a mean follow up of 39 months, one patient died from cancer and another from the sequelae of a stroke. In total, there were five NOT recurrences, three of which were complicated by embolic events without sequelae within eight months, and one by a recurrent stroke. In addition, three patients without demonstrable NOT recurrence suffered transient ischemic attacks. CONCLUSION: Among this small sample of patients, combined heparin and VKA was well tolerated and effective, and could prevent reoperation or thrombolysis. These observations may warrant further study in a larger patient population.

[Surgery for aortic valve stenosis after age 80 years]. / La chirurgie des sténoses aortiques après 80 ans.

Population aging in industrialized countries and advances in surgical care are leading to an increased number of elderly patients referred for surgical management of aortic stenosis (AS). Our report is a retrospective review of 988 consecutive patients aged 80 to 93 years (mean 82.4 +/- 2.3) who had aortic valve replacement (AVR) for AS. Surgical mortality was 9.4% (93 patients). Among 895 operative survivors, follow-up rate has been 99.7%, total 4446 patient-years (mean 5 +/- 3 years, max 19 years). Actuarial survival including operative mortality was 82%, 59% and 23% at two, five and ten years respectively. Functionnal recovery was excellent (46 % NYHA I and 43% NYHA II). Long term survival paralleled that of age and sex matched control population. Age itself is no longer a contraindication to surgery and AVR is the procedure of choice for elderly patients with aortic stenosis. Percutaneous aortic valve implantation is feasible and requires evaluation. It might become an alternative for selected high-risk non surgical patients with AS.

Eastern Caribbean Circulation and Island Mass Effect on St. Croix, US Virgin Islands: A Mechanism for Relatively Consistent Recruitment Patterns.

The northeastern Caribbean Sea is under the seasonal influence of the Trade Winds but also of the Orinoco/Amazon freshwater plume. The latter is responsible for intensification of the Caribbean Current in general and of its eddy activity in the northern part of the Caribbean Sea. More importantly, we show in this study that the front of the freshwater plume drives a northward flow that impinges directly on the island of St. Croix in the United States Virgin Islands. The angle of incidence of the incoming flow controls the nature of the wake on both sides and ends of the island, which changes from cyclonic to anticylonic wake flow, with either attached or shed eddies. Using an off-line bio-physical model, we simulated the dispersal and recruitment of an abundant Caribbean coral reef fish, the bluehead wrasse (Thalassoma bifasciatum) in the context of the wake flow variability around St. Croix. Our results revealed the role played by the consistent seasonal forcing of the wake flow on the recruitment patterns around the island at the interannual scale. The interannual variability of the timing of arrival and northward penetration of the plume instead controls the nature of the wake, hence the regional spatial recruitment patterns.

Predictors of 6-month poor clinical outcomes after transcatheter aortic valve implantation.

BACKGROUND: Patient selection for transcatheter aortic valve implantation (TAVI) remains a major concern. Indeed, despite promising results, it is still unclear which patients are most and least likely to benefit from this procedure. AIMS: To identify predictors of 6-month poor clinical outcomes after TAVI. METHODS: Patients who were discharged from our institution with a transcatheter-implanted aortic valve were followed prospectively. Our population was divided into two groups ('good outcomes' and 'poor outcomes') according to occurrence of primary endpoint (composite of all-cause mortality, all stroke, hospitalizations for valve-related symptoms or worsening heart failure from discharge to 6 months or 6-month New York Heart Association functional class III or IV). Patient characteristics were studied to find predictors of poor outcomes. RESULTS: We included 163 patients (mean age, 79.9 ± 8.8 years; 90 men [55%]; mean logistic EuroSCORE, 18.4 ± 11.4%). The primary endpoint occurred in 49 patients (mean age, 83 ± 5 years; 31 men [63%]). By multivariable analysis, atrial fibrillation (odds ratio [OR] 3.94), systolic pulmonary artery pressure ≥60 mmHg (OR 7.56) and right ventricular dysfunction (OR 3.55) were independent predictors of poor outcomes, whereas baseline aortic regurgitation ≥2/4 (OR 0.07) demonstrated a protective effect. CONCLUSION: Atrial fibrillation, severe baseline pulmonary hypertension and right ventricular dysfunction (i.e. variables suggesting a more evolved aortic stenosis) were predictors of 6-month poor outcomes. Conversely, baseline aortic regurgitation ≥2/4 showed a protective effect, which needs to be confirmed in future studies. Our study highlights the need for a specific 'TAVI risk score', which could lead to better patient selection.

Simple bedside clinical evaluation versus established scores in the estimation of operative risk in valve replacement for severe aortic stenosis.

BACKGROUND: The operative risk of cardiac surgery is ascertained preoperatively on the basis of scores validated in multinational studies. However, the value they add to a simple bedside clinical evaluation (CE) remains controversial. AIMS: To compare operative mortality (defined as death from all causes before the 31st postoperative day) predicted by CE with that predicted by additive and logistic EuroSCOREs, EuroSCORE II and Society of Thoracic Surgeons (STS), Ambler and age-creatinine-ejection fraction (ACEF) scores in patients undergoing aortic valve replacement (AVR) for severe aortic stenosis. METHODS: Overall, 314 consecutive patients were included who underwent AVR between October 2009 and November 2011 (22% with coronary artery bypass graft); mean age 73.4 ± 9.7 years (29% aged>80 years). Based on CE, patients were divided into four predefined groups of increasing estimated mortality risk: I ≤ 3.9%; II 4-6.9%; III 7-9.9%; IV ≥ 10%. The positive and negative predictive values of the six scores and CE were compared. RESULTS: The observed overall operative mortality was 5.7%. The distribution of the four predicted mortality groups by each score was highly variable. The positive predictive value, calculated for the 64 patients classified at highest risk by CE (groups III or IV) or each score, was 17.2% for EuroSCORE II, 14.1% for CE and STS scores, 10.9% for additive and logistic EuroSCOREs, 10.6% for ACEF and 10.2% for Ambler. The positive predictive value of each score in the low-risk groups (I and II) ranged from 2.8% to 4.4%. CONCLUSION: A simple bedside CE appears as reliable as the various established scores for predicting operative risk in patients undergoing surgical aortic valve replacement. The development and validation of more comprehensive risk stratification tools, including risk factors thus far neglected, seems warranted.

Prediction of left ventricular ejection fraction 6 months after surgical correction of organic mitral regurgitation: the value of exercise echocardiography and deformation imaging.

AIMS: Left ventricular (LV) end-systolic diameter and LV ejection fraction (LVEF) are correlated with postoperative LVEF and prognosis in patients with organic mitral regurgitation (MR). However, in some patients, the LVEF does not return to normal 6 months postoperatively, despite normal preoperative diameters. Thus, our study aimed to evaluate whether preoperative LV strain values assessed by echocardiography at rest and during exercise were predictors of postoperative LVEF at 6-month follow-up in patients undergoing surgery for severe organic MR. METHODS AND RESULTS: In total, 88 patients with severe organic MR (mean age 62.6 ± 1.4 years) were prospectively recruited. All patients underwent an echocardiogram at rest and submaximal exercise (110 ± 10 bpm) prior to surgery and then at rest 6 months after surgery. Exclusion criteria were significant coronary artery disease, other organic valvular diseases, uncontrolled arrhythmia, and haemodynamic instability. Among the 88 patients, 77 had complete data sets with rest and exercise echocardiograms and underwent isolated mitral valve surgery (repaired, n= 72). Global longitudinal strain (GLS) at rest (R= -0.42, P= 0.011) and during exercise (R= -0.36, P= 0.034) correlated with postoperative LVEF. When normalized for LV end-systolic diameter, GLS during exercise was more closely correlated with postoperative LVEF and was its best predictor based on a multivariate linear regression model. At a cut-off of -5.7%/cm, sensitivity was 0.83, specificity 0.70, negative predictive value 0.64, and positive predictive value 0.86 for predicting a 6-month postoperative LVEF of <50%. CONCLUSION: In patients undergoing surgery for severe organic MR, GLS normalized for LV end-systolic diameter at submaximal exercise may be used as a predictor of postoperative LVEF.

Predictive value of global longitudinal strain in a surgical population of organic mitral regurgitation.

BACKGROUND: Because of the lack of reliable echocardiographic parameters to predict recovery after surgery, the optimal timing of surgery for severe mitral regurgitation remains controversial. The aim of this study was to determine whether global longitudinal strain (GLS) recorded preoperatively could help in predicting left ventricular (LV) ejection fraction (LVEF) postoperatively. METHODS: A total of 88 patients (mean age, 63 ± 13 years; 59 men) with severe degenerative mitral regurgitation were included prospectively in this study. Rest echocardiography was performed before and 6 ± 1 months after mitral valve surgery. Patients were divided into two groups: group A (postoperative LVEF ≥ 50%) and group B (postoperative LVEF < 50%). RESULTS: In group B, patients had larger preoperative LV end-systolic diameters (21.6 ± 2.6 vs 19.2 ± 3.7 mm/m(2), P = .02) and impaired preoperative GLS (-17 ± 2.8% vs -19.6 ± 3.6%, P = .01), whereas there was no difference in preoperative LVEF. Preoperative LV end-systolic diameter ≥ 22 mm/m(2) and GLS < -18% were independent predictors of postoperative LV dysfunction. CONCLUSIONS: LV end-systolic diameter is a well-recognized prognostic marker. In addition, this study demonstrates the additive and independent predictive value of preoperative GLS for predicting postoperative LV dysfunction.

Aortic valve replacement for low-flow/low-gradient aortic stenosis operative risk stratification and long-term outcome: a European multicenter study.

OBJECTIVES: We evaluated a large multicenter series of patients operated on for low-flow/low-gradient aortic stenosis (LF/LGAS) to stratify the operative risk, assess whether perioperative mortality has decreased over recent years, and analyze the post-operative outcome. BACKGROUND: Although LF/LGAS is classically associated with a high operative risk, few data are available concerning the results of surgery in this setting. METHODS: A total of 217 consecutive patients (168 men, 77%) with severe aortic stenosis (area <1 cm(2)), low ejection fraction (EF) (

Pulmonary arterial hypertension in France: results from a national registry.

RATIONALE: Pulmonary arterial hypertension (PAH) is an orphan disease for which the trend is for management in designated centers with multidisciplinary teams working in a shared-care approach. OBJECTIVE: To describe clinical and hemodynamic parameters and to provide estimates for the prevalence of patients diagnosed for PAH according to a standardized definition. METHODS: The registry was initiated in 17 university hospitals following at least five newly diagnosed patients per year. All consecutive adult (> or = 18 yr) patients seen between October 2002 and October 2003 were to be included. MAIN RESULTS: A total of 674 patients (mean +/- SD age, 50 +/- 15 yr; range, 18-85 yr) were entered in the registry. Idiopathic, familial, anorexigen, connective tissue diseases, congenital heart diseases, portal hypertension, and HIV-associated PAH accounted for 39.2, 3.9, 9.5, 15.3, 11.3, 10.4, and 6.2% of the population, respectively. At diagnosis, 75% of patients were in New York Heart Association functional class III or IV. Six-minute walk test was 329 +/- 109 m. Mean pulmonary artery pressure, cardiac index, and pulmonary vascular resistance index were 55 +/- 15 mm Hg, 2.5 +/- 0.8 L/min/m(2), and 20.5 +/- 10.2 mm Hg/L/min/m(2), respectively. The low estimates of prevalence and incidence of PAH in France were 15.0 cases/million of adult inhabitants and 2.4 cases/million of adult inhabitants/yr. One-year survival was 88% in the incident cohort. CONCLUSIONS: This contemporary registry highlights current practice and shows that PAH is detected late in the course of the disease, with a majority of patients displaying severe functional and hemodynamic compromise.

Diagnostic strategy for patients with suspected pulmonary embolism: a prospective multicentre outcome study.

BACKGROUND: We designed a prospective multicentre outcome study to evaluate a diagnostic strategy based on clinical probability, spiral CT, and venous compression ultrasonography of the legs in patients with suspected pulmonary embolism (PE). The main aim was to assess the safety of withholding anticoagulant treatment in patients with low or intermediate clinical probability of PE and negative findings on spiral CT and ultrasonography. METHODS: 1041 consecutive inpatients and outpatients with suspected PE were included. Patients with negative spiral CT and ultrasonography and clinically assessed as having a low or intermediate clinical probability were left untreated. Those with high clinical probability underwent lung scanning, pulmonary angiography, or both. All patients were followed up for 3 months. FINDINGS: PE was diagnosed in 360 (34.6%) patients; 55 had positive ultrasonography despite negative spiral CT. Of 601 patients with negative spiral CT and ultrasonography, 76 were clinically assessed as having a high probability of PE; lung scanning or angiography showed PE in four (5.3% [95% CI 1.5-13.1]). The remaining 525 patients were assessed as having low or intermediate clinical probability, and 507 of them were not treated. Of these patients, nine experienced venous thromboembolism during follow-up (1.8% [0.8-3.3]). The diagnostic strategy proved inconclusive in 95 (9.1%) patients, and pulmonary angiography was done in 74 (7.1%). INTERPRETATION: Withholding of anticoagulant therapy is safe when the clinical probability of PE is assessed as low or intermediate and spiral CT and ultrasonography are negative.