Exotic Superfluid Phases in Spin-Polarized Fermi Gases in Optical Lattices.

Leveraging cutting-edge numerical methodologies, we study the ground state of the two-dimensional spin-polarized Fermi gas in an optical lattice. We focus on systems at high density and small spin polarization, corresponding to the parameter regime believed to be most favorable to the formation of the elusive Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid phase. Our systematic study of large lattice sizes, hosting nearly 500 atoms, provides strong evidence of the stability of the FFLO state in this regime, as well as a high-accuracy characterization of its properties. Our results for the density correlation function reveal the existence of density order in the system, suggesting the possibility of an intricate coexistence of long-range orders in the ground state. The ground-state properties are seen to differ significantly from the standard mean-field description, providing a compelling avenue for future theoretical and experimental explorations of the interplay between spin imbalance, strong interactions, and superfluidity in an exotic phase of matter.

Colchicine reduces postoperative atrial fibrillation: results of the Colchicine for the Prevention of the Postpericardiotomy Syndrome (COPPS) atrial fibrillation substudy.

BACKGROUND: Inflammation and pericarditis may be contributing factors for postoperative atrial fibrillation (POAF), and both are potentially affected by antiinflammatory drugs and colchicine, which has been shown to be safe and efficacious for the prevention of pericarditis and the postpericardiotomy syndrome (PPS). The aim of the Colchicine for the Prevention of the Post-Pericardiotomy Syndrome (COPPS) POAF substudy was to test the efficacy and safety of colchicine for the prevention of POAF after cardiac surgery. METHODS AND RESULTS: The COPPS POAF substudy included 336 patients (mean age, 65.7±12.3 years; 69% male) of the COPPS trial, a multicenter, double-blind, randomized trial. Substudy patients were in sinus rhythm before starting the intervention (placebo/colchicine 1.0 mg twice daily starting on postoperative day 3 followed by a maintenance dose of 0.5 mg twice daily for 1 month in patients ≥70 kg, halved doses for patients <70 kg or intolerant to the highest dose). The substudy primary end point was the incidence of POAF on intervention at 1 month. Despite well-balanced baseline characteristics, patients on colchicine had a reduced incidence of POAF (12.0% versus 22.0%, respectively; P=0.021; relative risk reduction, 45%; number needed to treat, 11) with a shorter in-hospital stay (9.4±3.7 versus 10.3±4.3 days; P=0.040) and rehabilitation stay (12.1±6.1 versus 13.9±6.5 days; P=0.009). Side effects were similar in the study groups. CONCLUSION: Colchicine seems safe and efficacious in the reduction of POAF with the potentiality of halving the complication and reducing the hospital stay.

6 months of "temporary" support by Levitronix left ventricular assist device.

An otherwise healthy 47-year-old man presented to the emergency department in cardiogenic shock after suffering a massive myocardial infarction due to left main occlusion. He was initially supported by extracorporeal membrane oxygenation and subsequently was converted to paracorporeal support with a Levitronix left ventricular assist device. He experienced multiple postoperative complications including renal failure, respiratory failure, retroperitoneal hematoma requiring suspension of anticoagulation, and fungal bloodstream infection precluding transition to an implantable device. He was reconditioned and successfully underwent orthotopic heart transplant 183 days after presentation. A discussion of the relevant issues is included.

Colchicine prevents early postoperative pericardial and pleural effusions.

BACKGROUND: No preventive pharmacologic strategies have been proven efficacious for the prevention of postoperative effusions after cardiac surgery. Colchicine is safe and efficacious for the prevention of pericarditis. On this basis, we realized a substudy of the COPPS trial to assess the efficacy and safety of colchicine for the prevention of postoperative pericardial and pleural effusions. METHODS: The COPPS is a multicenter, double-blind, randomized trial, where 360 consecutive patients (mean age 65.7 ± 12.3 years, 66% men), 180 in each treatment arm, were randomized on the third postoperative day to receive placebo or colchicine for 1 month (1.0 mg twice daily for the first day, followed by a maintenance dose of 0.5 mg twice daily in patients ≥70 kg, and halved doses for patients <70 kg). The incidence of postoperative effusions was evaluated in each study group. RESULTS: Despite similar baseline features, colchicine significantly reduced the incidence of postoperative pericardial (12.8% vs 22.8%, P = .019, relative risk reduction 43.9%, no. of patients needed to treat 10) and pleural effusions (12.2% vs 25.6%, P = .002, relative risk reduction 52.3%, no. of patients needed to treat 8). The rate of side effects (only gastrointestinal intolerance) and drug withdrawal was similar in the study groups with a trend toward an increased rate of both events for colchicine. In multivariable analysis, female gender (hazard ratio 1.76, 95% CI 1.03-3.03, P = .040) and pleura incision (hazard ratio 2.58, 95% CI 1.53-4.53, P < .001) were risk factors for postoperative effusions. CONCLUSIONS: Colchicine is safe and efficacious for the primary prevention of postoperative effusions after cardiac surgery.

A case of inefficient defibrillation during thoracotomy.

We describe the case of an accidental intraoperative ventricular fibrillation that could not be interrupted by a 35-J shock fired by an implantable cardioverter defibrillator (ICD). We believe that the iatrogenic pneumothorax induced by thoracotomy during the epicardial lead implant temporarily changed the intrathoracic impedance, causing an increase in defibrillation threshold. This possible change in impedance with resulting ineffective interruption of arrhythmia should be taken in consideration when a thoracotomy is planned in a patient bearing an ICD.

COlchicine for the Prevention of the Post-pericardiotomy Syndrome (COPPS): a multicentre, randomized, double-blind, placebo-controlled trial.

AIMS: No drug has been proven efficacious to prevent the post-pericardiotomy syndrome (PPS), but colchicine seems safe and effective for the treatment and prevention of pericarditis. The aim of the COlchicine for the Prevention of the Post-pericardiotomy Syndrome (COPPS) trial is to test the efficacy and safety of colchicine for the primary prevention of the PPS. METHODS AND RESULTS: The COPPS study is a multicentre, double-blind, randomized trial. On the third post-operative day, 360 patients (mean age 65.7 ± 12.3 years, 66% males), 180 in each treatment arm, were randomized to receive placebo or colchicine (1.0 mg twice daily for the first day followed by a maintenance dose of 0.5 mg twice daily for 1 month in patients ≥70 kg, and halved doses for patients <70 kg or intolerant to the highest dose). The primary efficacy endpoint was the incidence of PPS at 12 months. Secondary endpoint was the combined rate of disease-related hospitalization, cardiac tamponade, constrictive pericarditis, and relapses. Baseline characteristics were well balanced between the study groups. Colchicine significantly reduced the incidence of the PPS at 12 months compared with placebo (respectively, 8.9 vs. 21.1%; P = 0.002; number needed to treat = 8). Colchicine also reduced the secondary endpoint (respectively, 0.6 vs. 5.0%; P = 0.024). The rate of side effects (mainly related to gastrointestinal intolerance) was similar in the colchicine and placebo groups (respectively, 8.9 vs. 5.0%; P = 0.212). CONCLUSION: Colchicine is safe and efficacious in the prevention of the PPS and its related complications and may halve the risk of developing the syndrome following cardiac surgery. ClinicalTrials.gov number, NCT00128427.

Prevention of limb ischemia and edema during peripheral venoarterial extracorporeal membrane oxygenation in adults.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a mechanical circulatory support indicated for the advanced treatment of refractory heart failure. The cannulation of the femoral vessels may be complicated by distal limb ischemia by arterial hypoperfusion and severe edema by venous obstruction. We describe a modified cannulation technique in order to prevent ischemia and edema of the inferior limb during VA-ECMO.

Technique to prevent inadvertent paramedian sternotomy.

Previous reports documented the relationship between inadvertent paramedian sternotomy and postoperative sternal instability and dehiscence.We describe a modification of the technique of median sternotomy in order to prevent inadvertent paramedian sternotomy and related wound complications.

Initial results of clinical trial with a new left ventricular assist device (LVAD) providing synchronous pulsatile flow.

OBJECTIVES: A multicentric European Clinical Study is ongoing to evaluate safety and efficacy of a new pulsatile implantable LVAD (BestBeat), smaller and lighter than similar devices, capable of providing synchronous and counterpulsating flow with respect to the LV of end-stage heart failure patients. Preliminary clinical results are reported. METHODS: The new BestBeat LVAD was used, consisting of an implantable pulsatile blood pump, electromechanically driven by a ball screw mechanism, and a wearable electronic controller and power sources. The clinical trial was conducted at 5 european centers. Adult patients affected by CHF in NYHA Class IV despite optimized medical treatment were enrolled. The primary study endpoint was survival at 90 days. Further study endpoints were maintenance of adequate LVAD pump flow and a minimum rate of adverse events during support. RESULTS: As of June 2008, 6 patients received the implant. Cumulative support time was 3.7 years, median support time 176 days. All patients who completed the study survived except for one, who died after 48 days, due to combined infection and cerebrovascular accident. Another two patients died: one from intracranial bleeding 113 days after implant, and one from septic shock after 123 days. Hemodynamic improvement with CI>2.0 l/min/m2 and recovery of end-organ function expressed by consistent improvement of BUN, creatinine and bilirubin were reached in all patients. No device failure was observed. There was no bleeding requiring re-exploration, no hemolysis and only two device-related infections (both in one patient). Neurologic events were reported, the most serious ones occurring in patients with pre-implant respiratory and kidney failure. Three patients were discharged home. Two patients were successfully transplanted, one after 6 months and one after 13 months on device. CONCLUSIONS: Good performance and efficacy of the device were observed; the endpoints of the study were achieved, and its safety was consistent with expectations. The ongoing study will allow further conclusions to be drawn.

Ex-vivo characterization of three Björk-Shiley Delrin heart valves.

BACKGROUND AND AIM OF THE STUDY: Björk-Shiley Delrin (BSD) tilting-disc mechanical valve occluders have demonstrated good performance, with superior patient survival and low incidence of obstruction phenomena compared to caged-ball valves. Unfortunately, the use of Delrin as the occluder material was problematic, and in 1971 this led to its replacement with a pyrolitic carbon-coated occluder. The study aim was to report and to determine the mechanism of wear on BSD valve discs. To achieve this, three BSD valves which had been in place for between 312 and 355 months were explanted and analyzed. METHODS: Optical microscopy and scanning electron microscopy were used to investigate material imperfections or damage to the housing and occluder components of the explanted valves. RESULTS: The valve discs showed more than one type of wear pattern. Notably, the wear pattern observed on the surface and edge of the disc did not affect correct in-vivo function of the valves, as indicated by their long implantation period. No cracks, fractures or perforations of the Delrin discs were observed, but clear imprints caused by the impact of the struts on the inlet and outlet disc surfaces were detected. The depth of the strut imprints was indicative of a hindered disc rotation. A reduction in the diameter of the Delrin disc (ca. 1.44 mm) was detected in valve #3. CONCLUSION: The results obtained for the three BSD valves were in agreement with data reported elsewhere, and showed good performance of this mechanical valve. Although the clinical follow up for these second-generation mechanical valves is extensive and supportive of their good clinical performance, they may in time fail due to wear of the polymer surface.

Clinical outcome and bridge to transplant rate of left ventricular assist device recipient patients: comparison between continuous-flow and pulsatile-flow devices.

BACKGROUND: Long-term implantable continuous axial-flow pumps are increasingly used in bridging heart failure patients to heart transplant. Compared to pulsatile left ventricular assist devices (LVADs), they offer smaller dimensions, less surgical trauma and less thromboembolisms. However concerns still remain about the long-term effects of continuous-flow on patients' outcome. The aim of this study was to review our mechanical bridge to transplant experience to compare pre- and post-transplant outcomes between pulsatile and continuous-flow LVAD recipients. METHODS: Thirty-six patients with a continuous-flow device (Micromed DeBakey, Houston, TX or InCor Berlin Heart, Berlin, Germany--group A) were compared with 41 patients supported with a pulsatile device (Novacor, WorldHeart, Oakland, CA--group B). RESULTS: Mean age (48.6+/-12.4 vs 47.2+/-12.5) and LVAD duration (119.3+/-115.4 vs 128.3+/-198.3) were similar in the two groups. Group A recipients were smaller compared to group B (mean body surface area=1.77+/-0.18 vs 1.93+/-0.16; p<0.001). Idiopathic dilated cardiomyopathy was not significantly greater between the two groups (78% vs 58.3%; p=0.085). Successful bridging to transplantation was similar in group A compared to group B (52.8% vs 63.4%; p=non significant). On-VAD mortality was similar between the two groups (A vs B=33.3% vs 36.6%; p=non significant). Thirty-day mortality after HTx in group A was 10.5% compared to 7.7% in group B (p=non significant). First year post-transplant incidence of treated rejections (36.8% vs 46%; p=non significant) as the mean number of rejection/patient (0.38+/-0.5 vs 0.53+/-0.83; p=non significant) were similar in group A compared to group B. CONCLUSIONS: In our experience, when compared to pulsatile LVAD, continuous-flow pumps are similarly effective in transplant rate and post-transplant outcome.

Different clinical scenarios for circulatory mechanical support in acute and chronic heart failure.

Chronic heart failure (HF) is a leading cause of death in developed countries. Over the last 2 decades, mechanical circulatory support (MCS) devices have steadily evolved in the clinical management of end-stage HF and have emerged as a standard of care for the treatment of acute and chronic HF refractory to conventional medical therapy. Possible indications for using MCS are acute cardiogenic shock, as a bridge to transplantation, as a bridge to recovery, and more recently, as destination therapy in dilated cardiomyopathy, of either ischemic or idiopathic etiology. We reviewed the different clinical scenarios in which we think there are currently indications to implant different kinds of MCS systems.

Different applications for left ventricular mechanical support with the Impella Recover 100 microaxial blood pump.

The "Impella Recover 100" (IR100) is a new intravascular microaxial blood pump for use as short-term mechanical support for cases of acutely reduced left ventricular function. From September 2002 to April 2003, we used the IR100 to support 5 patients: 2 patients were bridged to heart transplant; 2 were being treated for fulminant acute myocarditis; and 1 for post-cardiotomy low-output syndrome. Only 1 patient with myocarditis died of septic shock, 2 had successful heart transplants; and the latter 2 were slowly weaned from the device and, at 3-month follow-up, showed moderate improvement of left ventricular (LV) function. Our initial experience with the IR100 as mechanical support for patients in cardiogenic shock of varying etiology has been positive, yielding good survival in a population of particularly compromised patients.

Surgical ablation of arrhythmias.

The surgical approach was the earliest therapeutic ablation of hyperkinetic arrhythmias. Following the progressive improvements in electrophysiological mapping and operative techniques, new surgical approaches have been developed for the treatment of those arrhythmias related to ectopic phenomena or reentry mechanisms. These procedures have been proven to be highly effective but the associated morbidity and mortality were unacceptably high. More recent and advanced techniques of transcatheter ablation have revolutionized the treatment of these arrhythmias and now represent the treatment of choice in the majority of cases. However, the significant reduction in the operative risk and the improvement in patient outcome with respect to the past, thanks to a better patient selection and to advances in the surgical and myocardial protection techniques, make do that the surgical approach to some forms of arrhythmias is still valid, especially in those cases requiring associated surgery: atrial tachyarrhythmias in patients with congenital heart disease, post-ischemic ventricular tachycardias in patients who necessitate myocardial revascularization, and/or ventricular remodeling and chronic or paroxysmal atrial fibrillation in patients who require cardiac surgery. New techniques such as radiofrequency, microwaves and cryoablation guarantee the creation of linear and transmural lesions with minimum damage to the cardiac structures and appear very interesting as they are surgically simple and associated with shorter procedure times and less complications. The possibility of performing the ablative procedure completely on the epicardial surface may open the way for atrial fibrillation surgery on a totally beating heart and for procedures that are ever less invasive thus enabling treatment of patients without associated surgical indications.

One-year clinical experience with the Acorn CorCap cardiac support device: results of a limited market release safety study in Italy and Sweden.

BACKGROUND: The Acorn CorCap cardiac support device (CSD) is a mesh-like device intended to provide end-diastolic support and reduce ventricular wall stress. Animal studies with the CorCap CSD have demonstrated beneficial reverse remodeling, and preliminary safety studies in patients with heart failure have shown that the device is safe and associated with improved left ventricular (LV) structure and function. The objective of the current study was to further evaluate the safety and efficacy of the CorCap CSD in patients with advanced heart failure. METHODS: Twenty-four patients with dilated cardiomyopathy, severe LV dysfunction, and advanced heart failure (NYHA class II-IV) were enrolled at four centers in Italy and Sweden. All patients underwent CorCap CSD implantation either alone (n = 3) or in combination with mitral valve repair/replacement (n = 13), coronary artery bypass surgery (n = 6), combined mitral valve repair/coronary artery bypass surgery (n = 1) or aneurysmectomy (n = 1). RESULTS: The LV end-diastolic diameter decreased from 69.3 +/- 7.2 to 60.1 +/- 9.0 mm at 3 months, 60.9 +/- 9.6 mm at 6 months, and 58.9 +/- 8.0 mm at 12 months (all p < 0.05). A trend toward an improved LV ejection fraction (28.8 +/- 10.5% at baseline and 32.4 +/- 12.7, 33.1 +/- 10.8, and 33.8 +/- 13.9% at 3, 6 and 12 months respectively) was also noted. The NYHA functional class, 6-min walking distance, and quality of life as measured using Uniscale were all improved. There were no differences in response among the patients submitted to the different types of concomitant surgery. CONCLUSIONS: In agreement with earlier safety studies, even the present investigation demonstrated improvements in cardiac structure and function as well as in patient functional status after Cor Cap CSD implantation. Randomized controlled trials are in progress.

Surgical therapy in advanced heart failure.

Congestive heart failure (CHF) affects about 1% of adults in the United States and is a contributing factor in >250,000 deaths per year. In an increasingly elderly population, the surgical treatment of CHF made great progress during the past 3 decades, consuming enormous health care resources. Heart transplantation is still the most effective therapy for end-stage heart disease, with the 10-year survival rate after transplantation approaching 50%. Efforts to increase the supply of donor organs have failed to improve the shortage, underscoring the crucial need for alternatives to cardiac allotransplantation. Alternative surgical options to end-stage heart transplantation are rapidly evolving. Left ventricular assist devices have been used as a bridge to heart transplantation for patients who otherwise might die awaiting a new heart. There is also continued interest in the use of these devices either to bridge patients to full recovery or to destination therapy, without the need for heart replacement. Left ventricular reconstruction, including the Batista and Dor procedures, along with mitral valve repair, cardiomyoplasty, and extreme coronary artery bypass graft surgery, are now being increasingly performed as alternative options. The history, status, and personal experience of surgical treatment of end-stage heart disease are discussed.

Clinical results with an ePTFE inflow conduit for mechanical circulatory support.

BACKGROUND: Neurologic complication is an adverse event associated with mechanical circulatory support. To decrease the incidence of embolic cerebrovascular accidents (CVA) during support with the Novacor left ventricular assist system (LVAS), an expanded polytetrafluoroethylene (ePTFE) inflow conduit has been developed and introduced clinically. METHODS: Using clinical data from Europe and Canada, we conducted a retrospective analysis of the incidence of embolic CVA with the ePTFE inflow conduit (n=88) in comparison with the previously used polyester inflow conduits (n=310, including Vascutek n=155 and Cooley n=155). We calculated freedom from embolic CVA, risk reduction for embolic CVA, and linearized rates of embolic CVA. RESULTS: A significant decrease in the incidence of embolic CVA was demonstrated with the ePTFE conduit (ePTFE 10% vs polyester 23%, p=0.002). Kaplan-Meier analysis of freedom from embolic CVA at 180 days after implantation was 86% for the ePTFE group vs 72% for the polyester group (log-rank test, 0.0185). We also found an associated risk reduction of 55% in CVA occurrence in the ePTFE group when compared with the Polyester group (hazard ratio, 0.445; 95% confidence limit, 0.222-0.890; p=0.0221). Linearized CVA rates also were decreased at all time intervals after implantation in the ePTFE group. CONCLUSIONS: Preliminary clinical results with the newly introduced ePTFE inflow conduit provide compelling evidence that the ePTFE conduit material significantly decreases thromboembolic complications during mechanical circulatory support with the Novacor LVAS.

Successful intraventricular thrombolysis during ventricular assist device support.

Different types of mechanical ventricular assist devices are available for treating end stage congestive heart failure. Despite technical improvements, however, various complications are still reported for patients during mechanical support. We report our experience with intraventricular thrombolysis as a treatment for possible thrombosis of a continuous flow device that had been implanted as a bridge to heart transplantation. This approach has been demonstrated to be both effective and safe.

Successful experience in bridging patients to heart transplantation with the MicroMed DeBakey ventricular assist device.

BACKGROUND: Pulsatile left ventricular assist devices are used with increasing frequency to bridge patients with end-stage heart failure to heart transplantation (HTx). Implantation of pulsatile devices is a cumbersome surgical procedure that is associated with major complications, such as bleeding, thromboembolism, and infection. Recently, a continuous axial flow left ventricular assist device (DeBakey ventricular assist device) has been introduced with the goal of reducing the incidence of major complications. METHODS: We reviewed our experience with 11 patients who received a DeBakey ventricular assist device axial flow pump for bridge to HTx from April 2000 through November 2001. RESULTS: Two patients (18.2%) died of multiple-organ failure while on left ventricular assist device support. Bleeding requiring thoracotomy occurred in 2 patients (18.2%). One patient had a minor neurologic event, and one patient developed left ventricular assist device thrombosis, which was successfully treated without pump exchange. Renal failure developed in 1 patient and hepatic dysfunction in 2 patients. There were no instances of right heart failure. No device, pocket, or drive-line infections occurred. Nine patients (9 of 11, 81.8%) had HTx within 51 +/- 49 days (range, 11 to 141 days) after left ventricular assist device implant. One patient died 29 days after HTx because of acute rejection. CONCLUSIONS: The continuous axial flow DeBakey ventricular assist device had reliable features, including a high rate of bridge to HTx. This device had low complication and system failure rates. We consider the DeBakey ventricular assist device a favorable alternative to pulsatile heart assist devices as a bridge to HTx.

Aortic complications after bicuspid aortic valve replacement: long-term results.

BACKGROUND: Bicuspid aortic valve (BAV) is a risk factor for aortic dissection and aneurysm. We studied patients with BAV and tricuspid aortic valve (TAV) to evaluate long-term changes in the ascending aorta after aortic valve replacement (AVR). PATIENTS AND METHODS: One hundred consecutive patients were allocated into two groups according to the presence of BAV (group A, 50 patients) or TAV (group B, 50 patients). Mean age was 51 +/- 12 years in group A, and 50 +/- years 12 in group B. No patients had hypertension or Marfan's syndrome. Until July 2001, mean follow-up was 234 +/- 47 months in group A and 241 +/- 43 months in group B. RESULTS: Five patients (10%, CL 5.7 to 13.9) in group A suffered late acute aortic dissection. Acute aortic dissection (5 vs 0, p = 0.0001) and sudden death (7 vs 0, p = 0.0001) occurred more frequently in patients with BAV. All survivors were assessed by echocardiogram. The mean diameter of the ascending aorta was 48.4 mm in group A and 36.8 mm in group B. Three patients in group A were operated on because of ascending aorta aneurysm more than 6 cm in diameter. CONCLUSIONS: As a result of our experience, we recommend a policy of prophylactic replacement of even a seemingly normal and definitely a mildly enlarged ascending aorta in cases of BAV at the moment of AVR, and consideration of a similar approach for any other cardiac surgical procedure in patients with BAV.