Richard J. Shemin

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

During the past decade, catheter ablation of atrial fibrillation (AF) has evolved rapidly from an investigational procedure to its current status as a commonly performed ablation procedure in many major hospitals throughout the world. Surgical ablation of AF, using either standard or minimally invasive techniques, is also performed in many major hospitals throughout the world. In 2007, an initial Consensus Statement on Catheter and Surgical AF Ablation was developed as a joint effort of the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society.1 The 2007 document was also developed in collaboration with the Society of Thoracic Surgeons and the American College of Cardiology. Since the publication of the 2007 document, there has been much learned about AF ablation, and the indications for these procedures have changed. Therefore the purpose of this 2012 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a Task Force, convened by the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society and charged with defining the indications, techniques, and outcomes of this procedure. Included within this document are recommendations pertinent to the design of clinical trials in the field of AF ablation, including definitions relevant to this topic. This statement summarizes the opinion of the Task Force members based on an extensive literature review as well as their own experience. It is directed to all health care professionals who are involved in the care of patients with AF, particularly those who are undergoing, or are being considered for, catheter or surgical ablation procedures for AF. This statement is not intended to recommend or promote catheter ablation of AF. Rather the ultimate judgment regarding care of a particular patient …

Three-dimensional electrospun ECM-based hybrid scaffolds for cardiovascular tissue engineering.

Electrospinning using natural proteins or synthetic polymers is a promising technique for the fabrication of fibrous scaffolds for various tissue engineering applications. However, one limitation of scaffolds electrospun from natural proteins is the need to cross-link with glutaraldehyde for stability, which has been postulated to lead to many complications in vivo including graft failure. In this study, we determined the characteristics of hybrid scaffolds composed of natural proteins including collagen and elastin, as well as gelatin, and the synthetic polymer poly(epsilon-caprolactone) (PCL), so to avoid chemical cross-linking. Fiber size increased proportionally with increasing protein and polymer concentrations, whereas pore size decreased. Electrospun gelatin/PCL scaffolds showed a higher tensile strength when compared to collagen/elastin/PCL constructs. To determine the effects of pore size on cell attachment and migration, both hybrid scaffolds were seeded with adipose-derived stem cells. Scanning electron microscopy and nuclei staining of cell-seeded scaffolds demonstrated the complete cell attachment to the surfaces of both hybrid scaffolds, although cell migration into the scaffold was predominantly seen in the gelatin/PCL hybrid. The combination of natural proteins and synthetic polymers to create electrospun fibrous structures resulted in scaffolds with favorable mechanical and biological properties.

The Society of Thoracic Surgeons Practice Guideline Series: Blood Glucose Management During Adult Cardiac Surgery

The Society of Thoracic Surgeons Practice Guideline Series : Blood Glucose Management During Adult Cardiac Surgery

Long-Term Clinical Outcome in the Bypass Angioplasty Revascularization Investigation Registry Comparison With the Randomized Trial

Background-The Bypass Angioplasty Revascularization Investigation (BARI) included 4039 patients with multivessel coronary artery disease; 1829 consented to randomization, and 2010 did not but were followed up in a registry. Thus, we can evaluate the outcome of physician-guided versus random assignment of percutaneous transluminal coronary angioplasty (PTCA) versus coronary artery bypass graft surgery (CABG). Methods and Results-We compared the baseline features and outcomes for PTCA and CABG in the overall registry and its predesignated subgroups. We assessed the impact of treatment by choice versus random assignment by comparing the results in the registry with those of the randomized trial. Statistical adjustments for differences in baseline characteristics were made. Within the registry, nearly twice as many patients were selected for PTCA (1189) as CABG (625); mortality at 7 years was similar for PTCA (13.9%) and CABG (14.2%) (P=0.66) before and after adjustment for baseline differences between patients selected for PTCA versus CABG (adjusted RR, 1.02; P=0.86). In contrast to the randomized trial, the 7-year mortality rate of treated diabetics in the registry was equally high (26%) with PTCA or CABG. Seven-year mortality was higher for patients undergoing PTCA in the randomized trial than in the registry (19.1% versus 13.9%, P<0.01) but not for those undergoing CABG (15.6% versus 14.2%, P=0.57). The adjusted relative mortality risk for PTCA in the randomized versus registry population was 1.17 (P=0.16). Conclusions-BARI physicians were able to select PTCA rather than CABG for 65% of registry patients who underwent revascularization without compromising long-term survival either in the overall population or in treated diabetics.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.

Glucose-insulin-potassium solutions enhance recovery after urgent coronary artery bypass grafting

OBJECTIVE This prospective, randomized, clinical study was undertaken to determine whether glucose-insulin-potassium solutions would benefit patients undergoing coronary artery bypass grafting because of unstable angina. METHODS The study group consisted of 30 patients with unstable angina who required coronary artery bypass grafting. In 15 patients, glucose-insulin-potassium solution (30% dextrose in water; K+, 80 mEq/L: regular insulin, 50 units) was given intravenously at 1 ml/kg per hour after induction of anesthesia and administration continued for 12 hours after aortic unclamping. Fifteen patients in a separate group received 5% dextrose in water intravenously at 50 ml/hr. RESULTS Patients treated with glucose-insulin-potassium solution had higher cardiac indices (2.8 +/- 0.1 vs 2.0 +/- 1 L/min per square meter; p < 0.001), lower inotrope scores (0.06 +/- 0.01 vs 0.46 +/- 0.19; p = 0.041), and less weight gain (6.4 +/- 9 vs 11.6 +/- 1.1 pounds; p < 0.001) and had shorter times of ventilator support (8.3 +/- 0.6 vs 14.2 +/- 0.2 hours; p = 0.003). They had a significantly lower incidence of atrial fibrillation (13.3% vs 53.3%; p = 0.020) and had shorter stays in the intensive care unit (14.8 +/- 1.3 vs 31.6 +/- 5.2 hours; p = 0.002) and in the hospital (6.0 +/- 0.4 vs 8.0 +/- 0.7 days; p = 0.010). CONCLUSIONS We conclude that glucose insulin-potassium therapy enhances myocardial performance and results in faster recovery from urgent coronary artery bypass grafting.

Shortage of Cardiothoracic Surgeons Is Likely by 2020

Background— Even as the burden of cardiovascular disease in the United States is increasing as the population grows and ages, the number of active cardiothoracic surgeons has fallen for the first time in 20 years. Meanwhile, the treatment of patients with coronary artery disease continues to evolve amid uncertain changes in technology. This study evaluates current and future requirements for cardiothoracic surgeons in light of decreasing rates of coronary artery bypass grafting procedures. Methods and Results— Projections of supply and demand for cardiothoracic surgeons are based on analysis of population, physician office, hospital, and physician data sets to estimate current patterns of healthcare use and delivery. Using a simulation model, we project the future supply of cardiothoracic surgeons under alternative assumptions about the number of new fellows trained each year. Future demand is modeled, taking into account patient demographics, under current and alternative use rates that include the elimination of open revascularization. By 2025, the demand for cardiothoracic surgeons could increase by 46% on the basis of population growth and aging if current healthcare use and service delivery patterns continue. Even with complete elimination of coronary artery bypass grafting, there is a projected shortfall of cardiothoracic surgeons because the active supply is projected to decrease 21% over the same time period as a result of retirement and declining entrants. Conclusion— The United States is facing a shortage of cardiothoracic surgeons within the next 10 years, which could diminish quality of care if non–board-certified physicians expand their role in cardiothoracic surgery or if patients must delay appropriate care because of a shortage of well-trained surgeons.

A prospective, randomized, crossover pilot study of inhaled nitric oxide versus inhaled prostacyclin in heart transplant and lung transplant recipients

OBJECTIVE Inhaled nitric oxide has been shown to reduce pulmonary vascular resistance in patients undergoing cardiothoracic surgery, but it is limited by toxicity, the need for special monitoring, and cost. Inhaled prostacyclin also decreases pulmonary artery pressure, is relatively free of toxicity, requires no specific monitoring, and is less expensive. The objective of this study was to compare nitric oxide and prostacyclin in the treatment of pulmonary hypertension, refractory hypoxemia, and right ventricular dysfunction in thoracic transplant recipients in a prospective, randomized, crossover pilot trial. METHODS Heart transplant and lung transplant recipients were randomized to nitric oxide or prostacyclin as initial treatment, followed by a crossover to the other agent after 6 hours. Pulmonary vasodilators were initiated in the operating room for pulmonary hypertension, refractory hypoxemia, or right ventricular dysfunction. Nitric oxide was administered at 20 ppm, and prostacyclin was administered at 20,000 ng/mL. Hemodynamic and oxygenation parameters were recorded before and after initiation of pulmonary vasodilator therapy. At 6 hours, the hemodynamic and oxygenation parameters were recorded again, just before discontinuing the initial agent. Crossover baseline parameters were measured 30 minutes after the initial agent had been stopped. The crossover agent was then started, and the hemodynamic and oxygenation parameters were measured again 30 minutes later. RESULTS Heart transplant and lung transplant recipients (n = 25) were randomized by initial treatment (nitric oxide, n = 14; prostacyclin, n = 11). Nitric oxide and prostacyclin both reduced pulmonary artery pressure and central venous pressure, and improved cardiac index and mixed venous oxygen saturation on initiation of therapy. More importantly, at the 6-hour crossover trial, there were no significant differences between nitric oxide and prostacyclin in the reduction of pulmonary artery pressures or central venous pressure, or in improvement in cardiac index or mixed venous oxygen saturation. Nitric oxide and prostacyclin did not affect the oxygenation index or systemic blood pressure. There were no complications associated with nitric oxide or prostacyclin. CONCLUSION In heart transplant and lung transplant recipients, nitric oxide and prostacyclin similarly reduce pulmonary artery pressures and central venous pressure, and improve cardiac index and mixed venous oxygen saturation. Inhaled prostacyclin may offer an alternative to nitric oxide in the treatment of pulmonary hypertension in thoracic transplantation.

Mitral valve repair in heart failure: Five-year follow-up from the mitral valve replacement stratum of the Acorn randomized trial

OBJECTIVE The study objective was to evaluate the long-term (5-year) safety and efficacy of mitral valve surgery with and without the CorCap cardiac support device (Acorn Cardiovascular, St Paul, Minn) in patients with dilated cardiomyopathy and New York Heart Association class II-IV heart failure. BACKGROUND The Acorn trial provided a unique opportunity to assess the long-term safety and efficacy of mitral valve surgery because clinical visits and echocardiograms (read by a core laboratory) were completed for 5 years of follow-up. Further, this study provided follow-up data on the long-term effect of the CorCap cardiac support device as an adjunct to mitral valve surgery. METHODS From the original Acorn trial (n = 300 patients), 193 patients were enrolled in the mitral valve repair/replacement stratum. A total of 102 were randomized to mitral valve surgery alone (control group) and 91 were randomized to mitral valve surgery with implantation of the CorCap cardiac support device (treatment group). Patients were followed up for 5 years. RESULTS As previously reported, 30-day operative mortality was only 1.6%. At 5 years, the total mortality was 30% with an average annual mortality rate of approximately 6% per year. The effects of mitral valve surgery led to a progressive decrease in left ventricular end-diastolic and end-systolic volumes, which were highly significant at all time points. At the end of 5 years, there was an average reduction in left ventricular end-diastolic volume of 75 mL, which represents a 28% reduction from baseline. During 5 years of follow-up, 29 patients had recurrent mitral regurgitation and 5 patients underwent repeat mitral valve surgery. The addition of the CorCap device led to greater decreases in left ventricular end-diastolic volume (average difference of 16.5 mL; P = .05), indicating that the CorCap device had an additive effect to the mitral valve operation. CONCLUSIONS This study demonstrates long-term improvement in left ventricular structure and function after mitral valve surgery for up to 5 years. These data provide evidence supporting mitral valve repair in combination with the Acorn CorCap device for patients with nonischemic heart failure with severe left ventricular dysfunction who have been medically optimized yet remain symptomatic with significant mitral regurgitation.

The use of three-dimensional nanostructures to instruct cells to produce extracellular matrix for regenerative medicine strategies

Synthetic polymers or naturally-derived extracellular matrix (ECM) proteins have been used to create tissue engineering scaffolds; however, the need for surface modification in order to achieve polymer biocompatibility and the lack of biomechanical strength of constructs built using proteins alone remain major limitations. To overcome these obstacles, we developed novel hybrid constructs composed of both strong biosynthetic materials and natural human ECM proteins. Taking advantage of the ability of cells to produce their own ECM, human foreskin fibroblasts were grown on silicon-based nanostructures exhibiting various surface topographies that significantly enhanced ECM protein production. After 4 weeks, cell-derived sheets were harvested and histology, immunochemistry, biochemistry and multiphoton imaging revealed the presence of collagens, tropoelastin, fibronectin and glycosaminoglycans. Following decellularization, purified sheet-derived ECM proteins were mixed with poly(epsilon-caprolactone) to create fibrous scaffolds using electrospinning. These hybrid scaffolds exhibited excellent biomechanical properties with fiber and pore sizes that allowed attachment and migration of adipose tissue-derived stem cells. Our study represents an innovative approach to generate strong, non-cytotoxic scaffolds that could have broad applications in tissue regeneration strategies.