Resection and double pericardial patch repair of a congenital aneurysm of the mitral-aortic intervalvular fibrosa.

Mitral-aortic intervalvular fibrosa aneurysms and pseudoaneurysms are rare entities but can lead to different, unpredictable and sometime dramatic complications. We report the case of a young woman presenting a congenital form of this aneurysm. Given the clinical and symptomatological progression, surgical treatment is mandatory. After a transverse aortotomy, we resected the aneurysm. Performing a pulmonary arteriotomy allows adequate control of the left main coronary artery, adjacent to the lesion. We repaired the remaining cavity, not far from the left coronary aortic cusp, with a double patch of bovine pericardium.

Predictors of Atrial Fibrillation After Coronary Artery Bypass Grafting: A Bayesian Analysis.

BACKGROUND: This study was conducted to identify preoperative predictors of postoperative atrial fibrillation (POAF) after isolated coronary artery bypass grafting (CABG) by using a Bayesian analysis that included information from prior studies. METHODS: We performed a prospective observational study from October 2008 to December 2013 of 1,481 patients who underwent isolated CABG with cardiopulmonary bypass and had no history of AF. Bayesian analysis was used to study the preoperative risks factors for POAF. RESULTS: The POAF incidence was 21%. Multivariate analysis identified the following independent predictors of POAF after CABG: high CHA2DS2-VASc (Congestive heart failure, Hypertension [blood pressure >140/90 mm Hg or treated hypertension on medication], Age ≥75 years, Diabetes mellitus, prior Stroke or transient ischemic attack or thromboembolism, vascular disease, Age 65 to 74 years, Sex category [female sex]) score (odds ratio [OR], 1.23; 95% credible interval [CI], 1.14 to 1.33 per 1-point increment, probability (Pr) [OR > 1] = 1), severe obesity with a body mass index of 35 kg/m2 or higher (OR, 1.28; 95% CI, 1.12 to 1.45; Pr [OR > 1] = 1), preoperative ß-blocker use (OR, 1.12; 95% CI, 1.06 to 1.20; Pr [OR > 1] = 1), preoperative antiplatelet therapy (OR, 1.75; 95% CI, 1.14 to 2.79, Pr [OR > 1] = 1), and renal insufficiency with a creatinine clearance of less than 60 mL/min (OR, 1.34; 95% CI, 1.03 to 1.74; Pr [OR > 1] = 1). CONCLUSIONS: This prospective Bayesian analysis identified five independent preoperative predictors of POAF after isolated CABG with cardiopulmonary bypass: CHA2DS2-VASc score, severe obesity, preoperative ß-blocker use, preoperative antiplatelet therapy, and renal failure. The main interest in the CHA2DS2-VASc score as a predictor of POAF is that it is a simple and widely used bedside tool. Patients with these independent predictors of POAF may constitute a target population to test preventive strategies, such as non-antiarrhythmic and antiarrhythmic drugs.

Trends in isolated coronary artery bypass grafting over the last decade.

OBJECTIVES: The purpose of this study was to assess the impact on hospital mortality and morbidity of extensive myocardial revascularization, using arterial grafts in patients undergoing isolated coronary artery bypass grafting (CABG). METHODS: Our prospective perioperative database was used to define two groups of patients who underwent isolated CABG with cardiopulmonary bypass, based on the years in which the operation was performed: Group A (2000-2003; 898 patients) and Group B (2009-2012; 1249 patients). The baseline and operative characteristics and outcomes were compared. RESULTS: Several significant changes in perioperative variables were observed. Group B included higher percentages of patients aged over 80 years (+58.1%), with diabetes (+32.0%) and with a history of percutaneous coronary intervention (+24.9%). The mean EuroSCORE II was significantly increased from 2.5 ± 4.4% in Group A to 3.2 ± 5.7% in Group B (P= 0.001). The mean number of distal anastomoses was significantly increased over time (total: 2.6 ± 0.8 vs 3.1 ± 1.0, P< 0.0001 and with arterial grafts: 1.6 ± 0.8 vs 2.6 ± 0.9, P< 0.0001). In-hospital mortality was low and did not significantly differ between Groups A and B (1.3 vs 2.4%; P= 0.08). Significant increases of new-onset atrial fibrillation (11.7 vs 21.9%, P= 0.017) and deep sternal infection (0.2 vs 1.1%, P= 0.017) were observed in Group B, compared with Group A. In multivariate analysis, extensive use of arterial grafts was not a risk factor of hospital mortality or sternal morbidity. CONCLUSIONS: Despite the increasing risk profiles of patients undergoing CABG, extensive myocardial revascularization using arterial grafts is associated with good early results.

Impact of prosthesis-patient mismatch on early haemodynamic status after aortic valve replacement.

OBJECTIVES: Prosthesis-patient mismatch (PPM) has been reported to impact early haemodynamic status and early mortality after prosthetic aortic valve replacement (AVR) in patients with aortic stenosis (AS). The aim of this study was to assess the impact of PMM on early haemodynamic status after AVR using vasoactive-inotropic dependency index (VDI), postoperative pressures and end-organ perfusion. METHODS: A total of 183 patients with AS were included in this prospective cohort study, and underwent elective AVR with or without combined coronary artery bypass graft surgery. PPM was defined as a projected indexed effective orifice area of ≤0.85 cm2/m2, and was present in 27.9% of the patients. The primary end-point was the VDI [VDI = vasoactive-inotropic score/mean arterial pressure] measured upon admission to the intensive care unit (POD0) and on the morning of the first postoperative day (POD1). The secondary end-points were the following: mean left atrial pressure, mean central venous pressure, fluid balance, brain natriuretic peptide, troponin I, glomerular filtration rate and lactate levels on POD0 and POD1. RESULTS: No significant differences in VDI were observed between the no PPM and PPM groups on POD0 (0.08 ± 0.48 vs 0.05 ± 0.13, respectively, P = 0.622) or on POD1 (0.09 ± 0.40 vs 0.06 ± 0.13, respectively; P = 0.583). The mean arterial pressure, mean left atrial pressure, central venous pressure, troponin I, glomerular filtration rate and lactate levels did not differ between the two groups on POD0 and POD1, as well as fluid balance and brain natriuretic peptide on POD1. CONCLUSIONS: PPM is not associated with early haemodynamic status impairment and end-organ perfusion after AVR. CLINICAL TRIAL NUMBER: ClinicalTrials.gov number, NCT00699673.

The prothrombotic paradox of severe obesity after cardiac surgery under cardiopulmonary bypass.

BACKGROUND: Obesity is suggested to reduce postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) but perioperative hemostasis variations have not been studied. Therefore, we investigated the effects of severe obesity (body mass index [BMI] ≥35kg/m(2)) on chest tube output (CTO) and hemostasis in patients undergoing cardiac surgery with CPB. MATERIALS AND METHODS: We prospectively investigated 2799 consecutive patients who underwent coronary and/or valve surgery using CPB between 2008 and 2012. 204 patients (7.3%) presented a severe obesity. RESULTS: In the severe obesity group, the 6-h and 24-h CTO were significantly reduced by -21.8% and -14.8% respectively (P<0.0001) compared with the control group. A significant reduction of the mean number of red blood cell units transfused at 24h was observed in the severe obesity groups (P=0.01). On admission to the intensive care unit, a significant increase of platelet count (+9.2%; P<0.0001), fibrinogen level (+12.2%; P<0.0001) and prothrombin time (+4.1%; P<0.01) and a significant decrease of the activated partial thromboplastin time (-4.2%; P<0.01) were observed in the severe obesity group compared with the control group. In multivariate analysis, severe obesity was significantly associated to a decreased risk of excessive bleeding (24-h CTO >90th percentile; Odds ratio: 0.37, 95% CI: 0.17 to 0.82). No significant differences were observed regarding postoperative thromboembolic events between the two groups. CONCLUSIONS: Severe obesity is associated with a prothrombotic postoperative state that leads to a reduction of postoperative blood loss in patients undergoing cardiac surgery with CPB.

Plasma fibrinogen level on admission to the intensive care unit is a powerful predictor of postoperative bleeding after cardiac surgery with cardiopulmonary bypass.

INTRODUCTION: Evidence regarding the behavior of fibrinogen levels and the relation between fibrinogen levels and postoperative bleeding is limited in cardiac surgery under cardiopulmonary bypass (CPB). To evaluate perioperative fibrinogen levels as a predictor of postoperative bleeding in patients undergoing cardiac surgery with CPB. MATERIALS AND METHODS: In this prospective, single-center, observational cohort study of 1956 patients following cardiac surgery with CPB, fibrinogen level was measured perioperatively. Excessive bleeding group was defined as patients with a 24-h chest tube output (CTO) exceeded the 90th percentile of distribution. RESULTS: The median 24-h CTO was 728.6±431.1ml. A total of 189 patients (9.7%) were identified as having excessive bleeding. At admission to the intensive care (Day 0), the fibrinogen levels were 2.5±0.8g/l and 2.1±0.8g/l in the control and excessive bleeding groups, respectively (P<0.0001). The fibrinogen level on Day 0 was significantly correlated with the 24-h CTO (rho=-0.237; P<0.0001). Multivariate analysis demonstrated that the fibrinogen level at Day 0 was the best perioperative standard laboratory test to predict excessive bleeding (P=0.0001; odds ratio, 0.5), whereas preoperative fibrinogen level was not a predictor. Using receiver operating characteristics curve analyses, the best Day 0 fibrinogen level cutoff to predict postoperative bleeding was 2.2g/l. CONCLUSIONS: In this large prospective study, the fibrinogen level upon admission to the intensive care unit after CPB predicted the risk of postoperative bleeding. Our data add to the concern regarding the fibrinogen level threshold that might require fibrinogen concentrate infusion to reduce postoperative blood loss.

Exclusive low-molecular-weight heparin as bridging anticoagulant after mechanical valve replacement.

BACKGROUND: Unfractionated heparin has been the standard anticoagulant used immediately after mechanical heart valve replacement (MHVR). The purpose of this study was to assess a postoperative anticoagulation protocol with low-molecular-weight heparin (LMWH) immediately after MHVR without the use of unfractionated heparin or anti-factor Xa monitoring. METHODS: We performed a prospective, single-center, observational study of 1,063 consecutive patients undergoing elective MHVR with postoperative LMWH anticoagulation treatment. The exclusion criteria were as follows: renal failure, intraaortic balloon counterpulsation, critical perioperative state, or a recent neurologic event. The postoperative anticoagulation protocol used subcutaneous enoxaparin as a bridging anticoagulant treatment beginning on the first postoperative day and continuing until vitamin K antagonist treatment was fully effective. Patients were followed for 6 weeks. The primary endpoints were the incidence of thromboembolic or major bleeding events. RESULTS: Eleven (1%) thromboembolic events occurred. Ten of these events were transient or permanent strokes. Major bleeding events occurred in 44 patients (4.1%), 7 of which were observed before the enoxaparin treatment period. At the time of discharge, 570 patients (53.6%) were no longer receiving LMWH treatment due to achieving the target international normalized ratio. The mean length of hospital stay was 8.5 ± 2.9 days. There were no deaths during the 6-week follow-up period. CONCLUSIONS: In our highly selected population, after MHVR, postoperative anticoagulation using LMWH is associated with a low rate of thromboembolic and major bleeding events. This large observational study demonstrates that the use of LMWH as an anticoagulant is effective and safe after MHVR.

Analytic expression for the mean time to absorption for a random walker on the Sierpinski gasket. II. The eigenvalue spectrum.

We continue the study of a particle (atom, molecule) undergoing an unbiased random walk on the Sierpinski gasket, and obtain for the gasket and tower the eigenvalue spectrum of the associated stochastic master equation. Analytic expressions for recurrence relations among the eigenvalues are derived. The recurrence relations obtained are compared with those determined for two Euclidean lattices, the closed chain with an absorbing site and a finite chain with an absorbing site at one end. We check and confirm the internal consistency between the smallest eigenvalue and the mean walklength in each of the cases studied. Attention is drawn to the relevance of the results obtained to a problem of electron transfer in proteins.

Aggregation of dipolar colloidal particles: geometric effects.

To understand the importance of confinement and the influence of translational degrees of freedom on aggregation of dipolar colloidal particles, we calculate numerically-exact values for the mean encounter time for two nonspherically symmetric molecules to form a two-molecule cluster, regarded here as a precursor to aggregation. A lattice model is formulated in which the asymmetry of the molecules is accounted for by representing each as a "dimer" in the sense that each molecule is specified to occupy two adjacent lattice sites. The two dimers undergo simultaneous translation, and the mean times for their encounter are determined. Exact numerical results are obtained via application of the theory of finite Markov processes. The results allow one to examine in a detailed way the interplay among such factors as geometrical confinement, system size, translational motion, and specific orientational effects in influencing the aggregation event. The results are compared with previously reported theoretical predictions and experiments on the behavior of dipolar colloidal particles in the presence of an applied magnetic field.