Niloo M. Edwards

Transapical Mitral Valved Stent Implantation

BACKGROUNDnTranscatheter aortic and pulmonary valve replacement is currently being tested in human trials. Efforts to create a valved stent to replace the atrioventricular valves have shown limited success. This is due to their their complex anatomy and function.nnnMETHODSnA self-expanding valved stent was created for transapical replacement of the atrioventricular valve. Ten pigs underwent transapical off-pump mitral valved stent implantation. Data were gathered to assess the animals hemodynamic stability for 60 minutes after implantation. The valved stent function was assessed by transesophageal echocardiography (TEE) and contrast left ventriculogram.nnnRESULTSnAll animals exhibited normal hemodynamics immediately after mitral valved stent implantation and maintained stability for the entire period of monitoring. Accurate positioning of the valved stent was established in all animals. Mild paravalvular regurgitation was found in three out of ten animals by TEE and in two animals during left ventriculogram. No left ventricular outflow tract obstruction was encountered.nnnCONCLUSIONSnTransapical off-pump mitral valved stent implantation is feasible in an acute experimental setting. Long-term function of the new valved stent remains to be established.

Off-pump transapical mitral valve replacement

OBJECTIVEnPercutaneous valve replacement was recently introduced, and reports of early clinical experience have already been published. To date, this technique is limited to the replacement of pulmonary and aortic valves in a strictly selected group of patients. The aim of this study was to analyse a self-expanding valved stent for minimally invasive replacement of the mitral valve in animals.nnnMETHODSnA newly designed nitinol stent was specially designed for this experimental acute study. It comprised of a left ventricular tubular stent with star shaped left atrial anchoring springs and carried a trileaflet bovine pericardial valve. A polytetrafluoroethylene membrane was sutured to envelop the atrial springs and the outside of the ventricular stent. The ventricular anchoring system was the same as in our previously reported results with a similar mitral valved stent. Seven pigs underwent minimally invasive off-pump mitral valved stent implantation. This was performed through a lower mini-sternotomy and a standard transapical approach under transoesophageal echocardiographic (TEE) guidance was used.nnnRESULTSnThe valved stent is fully retrievable and precise deployment and accurate adjustment of its intra-annular position is achievable to eliminate paravalvular leakage. The deployment time ranged from 127 to 255s and the blood loss from 70 to 220cc. One animal died of intractable ventricular fibrillation. Mitral regurgitation in all surviving animals was minimal (trace in 5/6 and mild in 1/6 during echo examination; on the contrast ventriculogram no mitral insufficiency was observed except in one documented as mild paravalvular regurgitation). These animals remained haemodynamically stable (6/6) and without TEE or ventriculographic changes for 1h.nnnCONCLUSIONnImplantation of a tricuspid bovine pericardial valved stent in the mitral position is feasible in pigs through a transcatheter approach. This was possible through a smaller delivery system than previously reported. Additional studies are required to demonstrate long-term feasibility, durability, and heart function.

Transapical mitral valved stent implantation: A survival series in swine

OBJECTIVEnTo assess short-term survival after transcatheter mitral valve replacement using a unique mitral valved stent design and anchoring system.nnnMETHODSnThe new nitinol self-expandable valved stent houses a trileaflet glutaraldehyde-preserved bioprosthesis and contains atrial and ventricular fixation systems. Eight pigs underwent transesophageal echocardiogram-guided transapical mitral valved stent implantation through a lower mini-sternotomy. Intracardiac pressure gradients were estimated by transesophageal echocardiogram.nnnRESULTSnThe mean mitral annulus size was 24.6 +/- 1.4 mm, and the valved stent size was 26.0 +/- 2.6 mm. The average mean transvalvular gradient across the valved stent immediately after deployment, at 6 hours, and after 1 week remained low. The gradient across the neighboring left ventricular outflow tract was not affected. Average animal survival was 7.3 days (8 hours to 29 days). Animals that died before 1 week (n = 4) were found at necropsy to have valved stent malpositioning. Animals that survived 1 week or more had accurate deployment and only trace post-deployment paravalvular leak. The causes of death in this latter group were endocarditis (n = 1), failure of atrial fixation (n = 2), and failure of ventricular fixation (n = 1). There was no valved stent embolization in any of the animals.nnnCONCLUSIONnAdequate function and effective anchoring of the new mitral valved stent allowed for short-term animal survival after transapical mitral valved stent implantation.

Successful Radiofrequency Ablation Therapy for Intractable Ventricular Tachycardia With a Ventricular Assist Device

Refractory ventricular tachycardia (VT) can be a potentially life-threatening rhythm in the presence of non-ischemic dilated cardiomyopathy, particularly when it results in hemodynamic compromise. A 65-year-old man with non-ischemic cardiomyopathy was referred for multiple episodes of VT. A HeartMate left ventricular assist device (LVAD) was implanted to stabilize and control the VT. However, he had multiple episodes of VT and the frequency of ventricular arrhythmias did not improve after LVAD implantation. He required electrical cardioversion to treat each episode. On Day 41 post-operatively, radiofrequency ablation was performed. Two significant areas of scarring were identified and were successfully ablated. After ablation, he did not have significant sustained VT episodes and was discharged.

Improved survival in patients with ventricular assist device therapy: the University of Wisconsin experience

OBJECTIVEnVentricular assist devices (VADs) have been implanted since 1990 in our institution, becoming an increasingly common treatment for end-stage heart failure. Beginning in 1997, VAD patients were discharged home when feasible. In August 2003, a dedicated multidisciplinary VAD team (cardiac surgeons, cardiologists, VAD coordinators, nurses, rehabilitation specialists, nutrition experts, psychologists, pharmacists, social workers, and administrators) was created to optimize the management of VAD patients. The purpose of this study is to analyze the impact of these changes in care at our center over the last 17 years.nnnMETHODSnWe retrospectively studied 107 consecutive VAD recipients between June 1990 and August 2006. VADs were implanted as bridge to recovery, bridge to transplant and destination therapy. The cohort was divided by care plans into early (n=37, June 1990-1996), mid (n=32, 1997-July 2003), and late groups (n=38, August 2003-August 2006). Demographic profile, survival and complications were assessed.nnnRESULTSnPatient demographics tended to show an increased severity of illness over time. Post-VAD survival rate significantly improved in the late group (post-VAD 1- and 3-year survival rates; early: 54.1% and 40.5%; mid: 51.6% and 41.9%; late: 86.8% and 82.5%, p<0.001, respectively). The incidence of complications including re-operation, major bleeding and major infection, significantly decreased in the late group (p<0.05).nnnCONCLUSIONSnOutcomes have improved dramatically in recent VAD patients, despite an increasingly high-risk patient population. These data suggest that advances in device technology and medical therapies, as well as a multidisciplinary approach, have improved survival on VAD therapy.

Patient preferences for coronary artery bypass graft surgery or percutaneous intervention in multivessel coronary artery disease.

Objectives: Determine if patients prefer multivessel percutaneous coronary intervention (mv‐PCI) over coronary artery bypass graft surgery (CABG) for treatment of symptomatic multivessel coronary artery disease (mv‐CAD) despite high 1‐year risk. Background: Patient risk perception and preference for CABG or mv‐PCI to treat medically refractory mv‐CAD are poorly understood. We hypothesize that patients prefer mv‐PCI instead of CABG even when quoted high mv‐PCI risk. Methods: 585 patients and 31 physicians were presented standardized questionnaires with a hypothetical scenario describing chest pain and medically refractory mv‐CAD. CABG or mv‐PCI was presented as treatment options. Risk scenarios included variable 1‐year risks of death, stroke, and repeat procedures for mv‐PCI and fixed risks for CABG. Participants indicated their preference of revascularization method based on the presented risks. We calculated the odds that patients or physicians would favor mv‐PCI over CABG across a range of quoted risks of death, stroke, and repeat procedures. Results: For nearly all quoted risks, patients preferred mv‐PCI over CABG, even when the risk of death was double the risk with CABG or the risk of repeat procedures was more than three times that for CABG (P < 0.0001). Compared to patients, physicians chose mv‐PCI less often than CABG as the risk of death and repeat procedures increased (P < 0.001 and P = 0.004, respectively). Conclusion: Patients favor mv‐PCI over CABG to treat mv‐CAD, even if 1‐year risks of death and repeat procedures far exceed risk with CABG. Physicians are more influenced by actual risk and prefer mv‐PCI less than patients despite similarly quoted 1‐year risks.

Improved Survival After Heart Transplantation in Patients With Bridge to Transplant in the Recent Era: A 17-year Single-center Experience

BACKGROUNDnVentricular assist device (VAD) implantation as a bridge to transplant (BTT) has become an important approach for heart transplant candidates. In this study we document our institutional long-term results and recent improvements in BTT therapy.nnnMETHODSnWe retrospectively studied 531 consecutive heart transplant recipients between January 1990 and August 2007. The cohort was divided into old orthotopic heart transplant (OHT) without device (oOHT; n = 399, January 1990 to July 2003), old BTT (oBTT; n = 41, January 1990 to July 2003), new OHT without device (nOHT; n = 58, August 2003 to August 2007) and new BTT (nBTT; n = 33, August 2003 to August 2007) groups. Demographics and post-transplant outcomes were assessed.nnnRESULTSnPost-transplant survival in the nBTT group improved significantly compared with the oBTT group (log-rank test, p = 0.01) and survival in the nOHT group tended to be higher than in the oOHT group (p = 0.19). Survival in the oBTT group was significantly worse than in the oOHT group (p < 0.01). However, there was no difference between the nBTT and nOHT groups. The mean period of BTT support was 113 (range 5 to 524) days in the oBTT group and 148 (range 38 to 503) days in the nBTT group. Multivariate analysis revealed diabetes (p < 0.01) and biventricular support (p = 0.04) as significant independent predictors of post-transplant mortality.nnnCONCLUSIONSnPost-transplant survival has improved in recent BTT patients. Indeed, recent outcome for OHT after BTT has become equivalent to that for OHT without VAD. These data suggest that advances in device technology and our institutional multidisciplinary program have improved survival and allow BTT candidates to have an outcome equivalent to that of non-VAD patients in the recent era.

Redo lung transplantation for acute and chronic lung allograft failure: long-term follow-up in a single center

OBJECTIVEnThis study was undertaken to evaluate outcomes of redo lung transplantation (LT) for acute and chronic graft failure.nnnMETHODSnBetween 1988 and 2007, 388 LT procedures were performed on 369 patients. From those, 17 (4.6%) patients had redo LT once and 2 patients had redo LT twice. Patient survival and recurrence of bronchiolitis obliterans syndrome (BOS) after redo LT were reviewed.nnnRESULTSnThe overall survival rates of the 17 redo LT recipients at 1, 2 and 5 years were 59+/-23%, 59+/-23% and 42+/-25%, respectively. For the chronic graft failure group (n=12), survival rates at 1, 2 and 5 years were 67+/-26%, 67+/-26% and 44+/-30%, respectively. These survival rates were significantly lower than the survival rates observed in our experience after primary LT (n=352, 1-, 2- and 5-year survival rates of 88+/-4%, 80+/-4% and 65+/-5%, respectively. For the acute graft failure group (n=5), the 1-year survival rate was 40%; two patients remain free from BOS. Two patients had a second redo LT, one died from multi-organ failure on postoperative day 86 and the other died from pulmonary aspergillosis on postoperative day 214.nnnCONCLUSIONSnRedo LT is a valid therapeutic option for selected patients with BOS and might be an option for highly selected patients with acute lung graft failure. Outcomes from a second redo LT are poor, and a second lung retransplantation must be used very cautiously, if at all.

Multidisciplinary approach decreases length of stay and reduces cost for ventricular assist device therapy

High implantation costs and long postoperative length of stay (LOS) in debilitated patients complicate ventricular assist device (VAD) therapy. Between July 2000 and February 2005, 30 patients received a VAD at our institution. Of those, 20 patients were successfully discharged from the hospital with VADs. In August 2003, a multidisciplinary team was formed consisting of all services for VAD patients to replace a single-discipline (cardiac surgery) system. This team evaluated potential VAD candidates and identified optimal timing for implantation. These 20 VAD patients were divided into two groups according to the initiation of multidisciplinary team; the traditional group (n=7, July 2000-July 2003) and the multidisciplinary group (n=13, August 2003-February 2005). Patient demographics were not different. The LOS decreased from 61 to 15 days (P<0.01), especially LOS on the floor decreased from 35 to 7 days (P=0.03). The floor cost was significantly reduced (

The potential of cardiac allografts from donors after cardiac death at the University of Wisconsin Organ Procurement Organization

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