Surgical Management of Coexisting Coronary Artery and Valvular Heart Disease

Purpose: Combined coronary artery bypass (CAB) and valve surgery is one of the most challenging surgical procedures, but the operative results have improved over the years. Materials and Methods: From 1989 through 2004, combined CAB and valve operations were performed in 125 patients. Mean age was 63 years, and 86 patients were male. Forty-six patients were diagnosed with coronary artery disease during preoperative evaluation for valvular heart disease (VHD). All patients underwent CAB, and one or more underwent valve replacement or repair (mitral: 54, aortic: 61, tricuspid: 3, DVR: 7) simultaneously. Results: Mean number of distal graft was 1.98 ± 1.07, and LIMA was used in 68 % of patients. Early mortality occurred in 6 patients (4.8%), and the causes were heart failure (4) and sepsis (2). Mean follow-up duration was 91.4 ± 40.9 months (range: 47-245), and late mortality occurred in 4 patients. Kaplan Meier estimated survival rates at 1, 5, and 10 years were 94.4 %, 92.3%, and 89.9%, respectively. Conclusion: Combined coronary and valve operations can be performed safely with optimal surgical results. Although the surgical mortality of coexisting coronary and VHD is higher than either isolated coronary or valvular operations, it may not affect the long-term survival

High-order dynamic Bayesian network learning with hidden common causes for causal gene regulatory network

Background: Inferring gene regulatory network (GRN) has been an important topic in Bioinformatics. Many computational methods infer the GRN from high-throughput expression data. Due to the presence of time delays in the regulatory relationships, High-Order Dynamic Bayesian Network (HO-DBN) is a good model of GRN. However, previous GRN inference methods assume causal sufficiency, i.e. no unobserved common cause. This assumption is convenient but unrealistic, because it is possible that relevant factors have not even been conceived of and therefore un-measured. Therefore an inference method that also handles hidden common cause(s) is highly desirable. Also, previous methods for discovering hidden common causes either do not handle multi-step time delays or restrict that the parents of hidden common causes are not observed genes. Results: We have developed a discrete HO-DBN learning algorithm that can infer also hidden common cause(s) from discrete time series expression data, with some assumptions on the conditional distribution, but is less restrictive than previous methods. We assume that each hidden variable has only observed variables as children and parents, with at least two children and possibly no parents. We also make the simplifying assumption that children of hidden variable(s) are not linked to each other. Moreover, our proposed algorithm can also utilize multiple short time series (not necessarily of the same length), as long time series are difficult to obtain. Conclusions: We have performed extensive experiments using synthetic data on GRNs of size up to 100, with up to 10 hidden nodes. Experiment results show that our proposed algorithm can recover the causal GRNs adequately given the incomplete data. Using the limited real expression data and small subnetworks of the YEASTRACT network, we have also demonstrated the potential of our algorithm on real data, though more time series expression data is needed

Effect of the prosthesis–patient mismatch on long-term clinical outcomes after isolated aortic valve replacement for aortic stenosis: A prospective observational study

BackgroundThe effect of prosthesis–patient mismatch (PPM) on clinical outcomes after aortic valve replacement remains controversial. We evaluated effect of PPM on long-term clinical outcomes after isolated aortic valve replacement in patients with predominant aortic stenosis.MethodsWe analyzed data from patients with predominant aortic stenosis who underwent isolated aortic valve replacement between January 1995 and July 2010. The indexed effective orifice area, obtained by dividing the in vivo effective orifice area by the patient’s body surface area, was used to define PPM as clinically nonsignificant (group I, 224 patients), mild (group II, 52 patients), moderate (group III, 39 patients), and severe (group IV, 36 patients).ResultsEarly survival was not significantly different among the groups, but overall survival was decreased gradually in group IV. Overall survival at 12 years was lower in group IV than in group I (92.8% ± 2.7% vs 67.0 ± 10.1, respectively; P = .001). Cardiac-related-death-free survival at 12 years was lower in patients with severe PPM. Left ventricular mass index decreased during the follow-up period in all groups. But left ventricular mass index was less decreased in group IV compared with groups I, II, and III. Age, severe PPM, and ejection fraction <40%, and New York Heart Association Functional Class IV were independent risk factors of overall survival on multivariate analysis. Severe PPM was an independent risk factor for cardiac-related death.ConclusionsSevere PPM showed an adverse effect on long-term survival, and was an independent risk factor for cardiac-related death. In addition, patients with severe PPM showed less decreasing left ventricular mass index during follow-up

Acupuncture Induced Necrotizing Aortitis with Infected Pseudoaneurysm Formation

Necrotizing aortitis is a rare and life-threatening complication of local or generalized bacterial infections and most commonly affects the abdominal aorta. We described a case of a 79-year-old man with an acupuncture-induced bacterial aortitis associated with pseudoaneurysm formation causing near rupture. The patient underwent emergent explolapartomy, resection of the infected aorta, wide debridement of surrounding infected tissues, and extra-anatomic axillary to bifemoral graft bypass. The microbiologic examination revealed Escherichia coli and methicillin resistant Staphylococcus aureus (MRSA). Necrotizing aortitis is very serious and fatal disease, careful history taking as well as rapid diagnosis and urgent treatment are of critical importance

Towards Personalized Healthcare in Cardiac Population: The Development of a Wearable ECG Monitoring System, an ECG Lossy Compression Schema, and a ResNet-Based AF Detector

Cardiovascular diseases (CVDs) are the number one cause of death worldwide. While there is growing evidence that the atrial fibrillation (AF) has strong associations with various CVDs, this heart arrhythmia is usually diagnosed using electrocardiography (ECG) which is a risk-free, non-intrusive, and cost-efficient tool. Continuously and remotely monitoring the subjects' ECG information unlocks the potentials of prompt pre-diagnosis and timely pre-treatment of AF before the development of any life-threatening conditions/diseases. Ultimately, the CVDs associated mortality could be reduced. In this manuscript, the design and implementation of a personalized healthcare system embodying a wearable ECG device, a mobile application, and a back-end server are presented. This system continuously monitors the users' ECG information to provide personalized health warnings/feedbacks. The users are able to communicate with their paired health advisors through this system for remote diagnoses, interventions, etc. The implemented wearable ECG devices have been evaluated and showed excellent intra-consistency (CVRMS=5.5%), acceptable inter-consistency (CVRMS=12.1%), and negligible RR-interval errors (ARE<1.4%). To boost the battery life of the wearable devices, a lossy compression schema utilizing the quasi-periodic feature of ECG signals to achieve compression was proposed. Compared to the recognized schemata, it outperformed the others in terms of compression efficiency and distortion, and achieved at least 2x of CR at a certain PRD or RMSE for ECG signals from the MIT-BIH database. To enable automated AF diagnosis/screening in the proposed system, a ResNet-based AF detector was developed. For the ECG records from the 2017 PhysioNet CinC challenge, this AF detector obtained an average testing F1=85.10% and a best testing F1=87.31%, outperforming the state-of-the-art

Clinical Results of Minimally Invasive Open-Heart Surgery in Patients with Mitral Valve Disease: Comparison of Parasternal and Low-Sternal Approach

Clinical results of minimally invasive mitral valve surgery were retrospectively reviewed, and two different surgical approaches were compared in this study. Between 1997 and 2004, a total of 86 patients with mitral valve disease underwent minimally invasive surgery at theYonsei University Cardiovascular Center. Age of patients averaged 41.6 ± 14.0 years and 69 patients were female. Surgical approach included lowsternal incisions with mini-sternotomy, and right parasternal or thoracotomy approach. Either direct aortic or femoral arterial and bicaval cannulations were used in all patients. Patients were divided into two groups according to the method of surgical approach (parasternal (P) vs low-sternal (L)), and the results were compared. Postoperative NYHA functional class improved to 1.1 ± 0.4 in all patients (no significant statistical difference between two groups). Mean wound length (P: 9.21 ± 1.10 vs L: 11.24 ± 0.82 cm, p<0.05), and mechanical ventilation time (P: 10.42 ± 4.36 vs L: 12.90 ± 5.00 min, p=0.04) was significantly shorter in parasternal group, and mean operation time(P:294.74 ± 59.41 vs. L:259.31 ± 54.36 min, p=0.03) was significantly shorter in low-sternal group. Mean cardiopulmonary bypass time, and aortic cross clamp time was also shorter in low-sternal group without statistical difference. There were 2 minor wound complications in all patients (p=NS), and no hospital death. Comparing the two different surgical approach of minimally invasive mitral valve surgery, parasternal approach is thought to be more beneficial in reducing postoperative scar, and intubation time

Earlier Application of Percutaneous Cardiopulmonary Support Rescues Patients from Severe Cardiopulmonary Failure Using the APACHE III Scoring System

Percutaneous cardiopulmonary support (PCPS) is a widely accepted treatment for severe cardiopulmonary failure. This system, which uses a percutaneous approach and autopriming devices, can be rapidly applied in emergency situations. We sought to identify the risk factors that could help predict in-hospital mortality, and to assess its outcomes in survivors. During a 2-yr period, 50 patients underwent PCPS for the treatment of severe cardiopulmonary failure, and of those, 22 (44%) were classified as survivors and 28 (56%) as non-survivors. We compared the 2 groups for risk factors of in-hospital mortality and to establish proper PCPS timing. Twenty patients underwent PCPS for acute myocardial infarction, 20 for severe cardiopulmonary failure after cardiac surgery, 7 for acute respiratory distress syndrome, and 3 for acute myocarditis. Multivariate analysis showed that an acute physiology, age, and chronic health evaluation (APACHE) III score ≥50 prior to PCPS was the only significant predictor of in-hospital mortality (P=0.001). Overall 18-month survival was 42.2%. Cox analysis showed patients with APACHE III scores ≥50 had a poor prognosis (P=0.001). Earlier application of PCPS, and other preemptive strategies designed to optimize high-risk patients, may improve patient outcomes. Identifying patients with high APACHE scores at the beginning of PCPS may predict in-hospital mortality. Survivors, particularly those with higher APACHE scores, may require more frequent follow-up to improve overall survival

Open Pulmonary Thromboembolectomy in Patients with Major Pulmonary Thromboembolism

PURPOSE: We retrospectively analyzed open pulmonary thromboembolectomy in patients with acute and chronic pulmonary thromboembolism. MATERIALS AND METHODS: Between August 1990 and May 2005, 12 consecutive patients with acute and chronic pulmonary thromboembolism underwent open pulmonary thromboembolectomy at Yonsei Cardiovascular Center. Their mean age was 47.5 years, and 7 of the patients were female. Among 12 patients, 5 had acute onset, and 7 had chronic disease, and 9 patients were associated with deep venous thrombosis. Extent of pulmonary embolism was massive in 3 patients with hemodynamic instability, and submassive in 8 patients. Preoperative echocardiogram revealed elevated right ventricular pressure in all patients, and 7 patients were in NYHA functional class III or IV. Pulmonary thromboembolectomy was performed in all patients under total circulatory arrest. RESULTS: There were 2 hospital deaths (16.7%). Among the patients who survived, mean right ventricular pressure was decreased significantly from 64.3mmHg to 34.0mmHg with improvement of NYHA functional class. CONCLUSION: Open pulmonary thromboembolectomy is thought to be an immediate and definitive treatment for massive pulmonary embolism with optimal results. Even though operative mortality is still high, early diagnosis and immediate surgical intervention in highly selective patients may improve the clinical outcomeope

Reexamination of the long-range Potts model: a multicanonical approach

We investigate the critical behavior of the one-dimensional q-state Potts model with long-range (LR) interaction $1/r^{d+\sigma}$, using a multicanonical algorithm. The recursion scheme initially proposed by Berg is improved so as to make it suitable for a large class of LR models with unequally spaced energy levels. The choice of an efficient predictor and a reliable convergence criterion is discussed. We obtain transition temperatures in the first-order regime which are in far better agreement with mean-field predictions than in previous Monte Carlo studies. By relying on the location of spinodal points and resorting to scaling arguments, we determine the threshold value $\sigma_c(q)$ separating the first- and second-order regimes to two-digit precision within the range $3 \leq q \leq 9$. We offer convincing numerical evidence supporting $\sigma_c(q)Comment: 18 pages, 18 figure