Ventricular assist device in patients with prosthetic heart valves

Ventricular assist device (VAD) support inpatients with a prosthetic heart valve had previously been considered a relative contraindication due to an increased risk of thromboembolic complications. We report our clinical experience of VAD implantation in patients with prosthetic heart valves, including both mechanical and bioprosthetic valves. The clinical records of 133 consecutive patients who underwent VAD implantation at a single institution from January 2002 through June 2009 were retrospectively reviewed. Six of these patients had a prosthetic valve in place at the time of device implantation. Patient demographics,operative characteristics, and postoperative complications were reviewed.Of the six patients,four were male.The mean age was 57.8 years (range 35–66 years). The various prosthetic cardiac valves included a mechanical aortic valve (n = 2), a bioprosthetic aortic valve (n = 3), and a mechanical mitral valve (n = 1).The indications for VAD support included bridge to transplantation (n = 2), bridge to recovery (n = 1), and postcardiotomy ventricular failure(n = 3). Three patients underwent left ventricular assist device placement and three received a right ventricular assist device. Postoperatively, standard anticoagulation management began with a heparin infusion (if possible)followed by oral anticoagulation.The 30-day mortality was50% (3/6). The mean duration of support among survivors was 194.3 days (range 7–369 days) compared with 16.0 days(range 4–29 days) for nonsurvivors. Of the three survivors,two were successfully bridged to heart transplantation and one recovered native ventricular function.Among the three nonsurvivors,acute renal failure developed in each case, and two developed heparin-induced thrombocytopenia. This study suggests that VAD placement in patients with a prosthethic heart valve, either mechanical or bioprosthetic,appears to be a reasonable option.     

Improved Results for Postcardiotomy Cardiogenic Shock With the Use of Implantable Left Ventricular Assist Devices

Background. Over the past decade, the use of mechanical circulatory support in patients with postcardiotomy cardiogenic shock has resulted in hospital discharge rates of 25% to 40%. In an attempt to improve patient survival, we initiated a program of early insertion of an implantable Thermocardiosystems Incorporated Heartmate left ventricular assist device in patients who have circulatory failure after having undergone high-risk cardiac operations.

Methods. Between April 1993 and February 1997, 12 patients underwent insertion of an implantable left ventricular assist device for postcardiotomy cardiogenic shock after coronary artery bypass grafting. Indications for insertion included postoperative cardiogenic shock (7 patients), postoperative cardiac arrest (3 patients), and failure to wean from cardiopulmonary bypass (2 patients).

Results. The median time to device insertion was 3.5 days. The mean duration of left ventricular assist device support was 103 ± 19 days (range, 2 to 225 days). Nine of 11 patients (82%) survived to undergo either transplantation (8 patients) or explantation (1 patient), with successful hospital discharge of all 9 patients. The major complication was device-related infection (42%). A single thromboembolism occurred in a patient with an infection.

Conclusions. Long-term outcome after postcardiotomy cardiogenic shock is improved substantially with the use of an implantable left ventricular assist device early in the postoperative course. Access to such a device is an important consideration before undertaking a high-risk cardiac operation, and early implantation of the device is a critical factor in ensuring long-term survival.     

Ventricular assist device support in patients with mechanical heart valves

Background. Due to potential thromboembolic complications, mechanical valves within the native heart are often considered contraindications to ventricular assist device (VAD) support.

Methods. A retrospective review of VAD cases between June 1982 and March 1998 showed 8 patients with mechanical valves who were supported with Thoratec (Pleasanton, CA) VADs.

Results. There were 6 males and 2 females ranging in age from 20 to 69 years (mean 49.8 ± 5.6). Four patients were supported when they could not be weaned from cardiopulmonary bypass after reparative procedures and were thought to have reversible injuries. Four patients were supported as a bridge-to-cardiac transplantation. Two patients had mechanical mitral valves, 2 had aortic valve replacements, 1 had an aortic homograft and mechanical mitral valve, 2 had mechanical aortic and mitral prosthesis, and 1 patient had aortic, mitral, and triscupid valves. The types of valvular prostheses were St. Jude (5 patients) and Bjork-Shiley (3 patients). Duration of support ranged from 3.0 to 150 days (mean 34 days). Four patients were supported with biventricular assist devices and 4 had left VADs. Dextran and intravenous heparin anticoagulation were used in the shorter duration patients, with warfarin being used in the bridge patients. One patient received warfarin and aspirin. At the time of autopsy or device removal, only 1 of the 12 mechanical intracardiac valves showed any evidence of thrombosis, including the aortic valves in 2 patients supported for 2 and 5 months. There were no clinical thromboembolic events. Four patients (50%) were discharged (1 weaned, 3 transplanted).

Conclusions. The 50% (4 of 8) survival rate compares favorably with the 44% (41 of 92) overall survival rate for our Thoratec patients (bridge plus recovery) who did not have mechanical prosthetic valves. These data suggest that patients with mechanical intracardiac valves can be supported for short durations with some additional risk, which is yet to be determined.     

Long-term follow-up of Thoratec ventricular assist device bridge-to-recovery patients successfully removed from support after recovery of ventricular function.

BACKGROUND: In certain forms of severe heart failure there is sufficient improvement in cardiac function during ventricular assist device (VAD) support to allow removal of the device. However, it is critical to know whether there is sustained recovery of the heart and long-term patient survival if VAD bridging to recovery is to be considered over the option of transplantation. METHODS: To determine long-term outcome of survivors of VAD bridge-to-recovery procedures, we retrospectively evaluated 22 patients with non-ischemic heart failure successfully weaned from the Thoratec left ventricular assist device (LVAD) or biventricular assist device (BVAD) after recovery of ventricular function at 14 medical centers. All patients were in imminent risk of dying and were selected for VAD support using standard bridge-to-transplant requirements. There were 12 females and 10 males with an average age of 32 (range, 12-49). The etiologies were 12 with myocarditis, 7 with cardiomyopathies (4 post-partum [PPCM], 1 viral [VCM], and 2 idiopathic [IDCM]), and 3 with a combination of myocarditis and cardiomyopathy. BVADs were used in 13 patients and isolated LVADs in 9 patients, for an average duration of 57 days (range, 11-190 days), before return of ventricular function and successful weaning from the device. Post-VAD survival was compared with 43 VAD bridge-to-transplant patients with the same etiologies who underwent cardiac transplantation instead of device weaning. RESULTS: Nineteen of the 22 patients are currently alive. Three patients required heart transplantation, 1 within 1 day, 2 at 12 and 13 months post-weaning, and 2 died at 2.5 and 6 months. The remaining 17 patients are alive with their native hearts after an average of 3.2 years (range, 1.2-10 years). The actuarial survival of native hearts (transplant-free survival) post-VAD support is 86% at 1 year and 77% at 5 years, which was not significantly different (p = 0.94) from that of post-VAD transplanted patients, also at 86% and 77%, respectively. CONCLUSIONS: Long-term survival for bridge-to-recovery with VADs for acute cardiomyopathies and myocarditis is equivalent to that for cardiac transplantation. Recovery of the native heart, which can take weeks to months of VAD support, is the most desirable clinical outcome and should be actively sought, with transplantation used only after recovery of ventricular function has been ruled out.     

Heart Transplantation: A Single-Center Experience

Background. The success of heart transplantation led to the extension of the criteria for both recipients and donors. The aim of the study was to evaluate the experience with this therapeutic approach for end-stage heart failure at a single center.

Methods. Between April 1986 and January 1996, 1,413 patients were accepted as candidates for heart transplantation. Ventricular assist devices were used as a bridge to transplantation in 173 patients (biventricular assist device in 141 patients and left ventricular assist device in 32 patients). The longest duration of support was 572 days (average, 46 days).

Results. Of the 1,413 patients, 891 underwent heart transplantation (65 children/adolescents and 826 adults; 522 (36%) patients died awaiting a donor heart. The average time spent on the waiting list was 107 days. The average recipient age was 44 years, and the age of donors was extended up to 69 years. Eighty-three patients with ventricular assist devices (48%) subsequently underwent heart transplantation. Twenty-five patients (2.7%) underwent retransplantation. The 30-day mortality rate was 14%, and the overall actual survival at 1, 5, and 10 years was 80%, 59%, and 50%, respectively. Ninty-four percent of patients were in New York Heart Association functional class I or II at 1 year, and 44% returned to work after transplantation.

Conclusions. Despite the broadening of the selection criteria for both recipients and donors, heart transplantation remains an effective treatment for end-stage heart failure. Nevertheless, this therapeutic approach is severely limited by a considerable disparity between the need and availability of donor organs.     

Application of "double bridge mechanical" resuscitation for profound cardiogenic shock leading to cardiac transplantation

BACKGROUND: In patients with acute profound cardiogenic circulatory failure unresponsive to conventional resuscitation, we instituted immediate aggressive application of extracorporeal membrane oxygenation (ECMO) to restore circulatory stability. Long-term hemodynamic support was accomplished with an early "bridge" to ventricular assist device (VAD) before definitive treatment with cardiac transplantation. METHODS: A respective review of ECMO and VAD data registries was instituted. RESULTS: From May 1996 to July 2000, 23 patients were placed on ECMO support for profound cardiogenic circulatory failure. Eleven patients (47%) were withdrawn from support due to severe neurologic injury or multisystem organ failure. Three patients (13%) were weaned off ECMO with good outcome. Nine patients (39%) were transferred to a VAD. Two patients expired while on VAD support, and 7 of the VAD-supported patients (78%) survived to transplantation. Overall survival was 43%. CONCLUSIONS: Emergent ECMO support is a salvage approach for cardiac resuscitation once conventional measures have failed. In neurologically intact patients, the early transfer to a VAD quickly stabilizes hemodynamics, avoids complications, and is essential for long-term circulatory support before definitive treatment with cardiac transplantation.     

Experience with over 1000 implanted ventricular assist devices

PURPOSE: The use of ventricular assist devices (VADs) in patients with chronic end-stage or acute heart failure has led to improved survival. We present our experience since 1987. SUBJECTS AND METHODS: Between July 1987 and December 2006, 1026 VADs were implanted in 970 patients. Most of them were men (81.9%). The indications were: cardiomyopathy (n = 708), postcardiotomy heart failure (n = 173), acute myocardial infarction (n = 36), acute graft failure (n = 45), a VAD problem (n = 6), and others (n = 2). Mean age was 46.1 (range 3 days to 78) years. In 50.5% of the patients the VAD implanted was left ventricular, in 47.9% biventricular, and in 1.5% right ventricular. There were 14 different types of VAD. A total artificial heart was implanted in 14 patients. RESULTS: Survival analysis showed higher early mortality (p < 0.05) in the postcardiotomy group (50.9%) than in patients with preoperative profound cardiogenic shock (31.1%) and patients with preoperative end-stage heart failure without severe shock (28.9%). A total of 270 patients were successfully bridged to heart transplantation (HTx). There were no significant differences in long-term survival after HTx among patients with and without previous VAD. In 76 patients the device could be explanted after myocardial recovery. In 72 patients the aim of implantation was permanent support. During the study period 114 patients were discharged home. Currently, 54 patients are on a device. CONCLUSIONS: VAD implantation may lead to recovery from secondary organ failure. Patients should be considered for VAD implantation before profound, possibly irreversible, cardiogenic shock occurs. In patients with postcardiotomy heart failure, a more efficient algorithm should be developed to improve survival. With increased experience, more VAD patients can participate in out-patient programs.     

心脏瓣膜术后心室辅助治疗

目的 总结瓣膜病变术后重症心衰病人置入心室辅助(VADs)装置时,心脏瓣膜或人工瓣膜处理方法及围术期抗凝管理的经验.方法 回顾1994年1月到2008年6月,宾夕法尼亚大学附属医院心脏中心157例置入VADs病人中,10例为瓣膜术后重症心衰者.对于二尖瓣和三尖瓣病变,无论成形或置换,置入VADs时均未处理原瓣膜或人工瓣膜(环).5例主动脉瓣病变病例置入VADs时,2例用生物瓣膜取代了原机械瓣膜,1例未处理原来生物瓣膜,1例未处理原机械瓣膜,1例取出机械瓣膜,用牛心包封闭主动脉根部.结果 所有病人置入VADs术后应用抗凝治疗.10例病人中,停VAD出院和VAD姑息治疗各1例;转心脏移植4例;4例死亡,3例为多器官衰竭,1例为血栓栓塞事件.结论 瓣膜病变术后置入VADs总的生存率是60%,与非瓣膜病心衰病人置入VADs相比,未增加手术风险.

Abstract：

Objective An increasing number of patients requiring ventricular assist devices (VAD) have had previous valvular corrections,including valve repair,and valve replacement with mechanical or bioprosthetic valves.The operative and peri-operative management of these patients has been varied.Methods A retrospective study of VADs between Jan 1994 and June 2008 revealed 10 patients with previous prosthetic valves requiring management during and after VAD placement.Three patients were supported post-cardiotomy after valve surgery.Two patients were supported due to cardiogenic shock postopera-tively.Four patients were supported as a bridge to transplantation.One patient was supported as a destination therapy.Results The mitral valve was left untreated during VAD implantation regardless of valve repair or replacement.For aortic valves,the mechanical aortic valve was replaced with tissue valve in two patients and left untreated in one case.One patient had tricuspid valve repair previously and was left untouched.All patients with prosthetic valves in aortic,mitral and tricuspid position during VAD support received anticoagulation therapy.There were 4 deaths,and 4 went on to transplantation.One patient weaned from VAD and discharge from hospital.One patient received HeartMate Ⅰ as destination therapy.The most common causes of death were multisystem organ failure and sepsis.One patient had a thromboembolic event.Conclusion The survival rate of 60% is encouraging when compared to overall survival rates.The most common cause of death was multisystem organ failure.Patients with prosthetic valves may be safely managed during VAD support.     

First Clinical Application of the DuraHeart Centrifugal Ventricular Assist Device for a Japanese Patient

The DuraHeart ventricular assist device (VAD) is a third-generation implantable centrifugal pump with a magnetically levitated impeller. Since February 2007, the device has been clinically applied with excellent results as a bridge to heart transplantation in Europe. As of this writing, however, the device has yet to be approved by the Ministry of Health, Labour and Welfare for clinical use in Japan. We herein report the first clinical application of this device for a Japanese patient. A 31-year-old man with dilated cardiomyopathy was transferred to the Heart and Diabetes Center NRW (HDZ-NRW) in Bad Oeynhausen, Germany, where he was to await heart transplantation. The transfer was safely completed under management with low-dose dopamine. His condition gradually deteriorated at HDZ-NRW, and the DuraHeart left ventricular assist device was implanted for the left ventricle at 7 weeks after admission. Shortly thereafter, however, on POD 7, a Thoratec VAD had to be inserted on the right side due to refractory right heart failure. The right ventricular assist device could be explanted after a 3-month assist, and the patient is now waiting for heart transplantation at home in Germany.     

Towards the development of a pediatric ventricular assist device

The very limited options available to treat ventricular failure in children with congenital and acquired heart diseases have motivated the development of a pediatric ventricular assist device at the University of Pittsburgh (UoP) and University of Pittsburgh Medical Center (UPMC). Our effort involves a consortium consisting of UoP, Children's Hospital of Pittsburgh (CHP), Carnegie Mellon University, World Heart Corporation, and LaunchPoint Technologies, Inc. The overall aim of our program is to develop a highly reliable, biocompatible ventricular assist device (VAD) for chronic support (6 months) of the unique and high-risk population of children between 3 and 15 kg (patients from birth to 2 years of age). The innovative pediatric ventricular assist device we are developing is based on a miniature mixed flow turbodynamic pump featuring magnetic levitation, to assure minimal blood trauma and risk of thrombosis. This review article discusses the limitations of current pediatric cardiac assist treatment options and the work to date by our consortium toward the development of a pediatric VAD.     

HeartMate Left Ventricular Assist Device as Bridge to Heart Transplantation

Background. Because of the limited supply of donor hearts, prospective recipients continue to die while on the waiting list for heart transplantation. Use of long-term mechanical circulatory support devices as a bridge to transplantation may reduce this mortality. However, with the present state of technology, continued clinical evaluation of the various long-term, mechanical circulatory support devices available is mandatory.

Methods. Sixteen patients were bridged with the HeartMate left ventricular assist device (LVAD) to heart transplantation for New York Heart Association functional class IV cardiac failure. Twelve pneumatic and six electric devices were used. The mean cardiac index and the mean pulmonary vascular resistance of the patient cohort were 1.7 1 · min⁻¹ · m⁻² and 3.1 Wood units, respectively.

Results. The mean LVAD support time per transplanted patient was 237 days, with a cumulative LVAD support time of about 7.2 years. Bleeding was the main operative and postoperative complication. Two patients suffered from neurologic complications and there were two major incidents of device malfunction. Twelve patients (75%) now have received a transplant, 3 (19%) are awaiting a transplant, and in 1 patient (6%), the device was explanted after spontaneous left ventricular recovery. Eleven of the 12 patients who received a transplant are alive and doing well. The HeartMate LVAD gave adequate circulatory support over extended periods of time and reversed the vital organ dysfunction. Since the start of the LVAD program, only 1 patient has died on our heart transplantation waiting list, compared to nine deaths in the 2 preceding years.

Conclusions. The HeartMate LVAD bridge to heart transplantation can be performed with low post-LVAD implantation and posttransplantation mortality and offers 1- and 2-year posttransplantation actuarial survival rates comparable to those for nonbridged heart transplant recipients.     

Emergent mechanical support in the community: improvement with early transplant center referral.

Emergent mechanical support for the failing ventricle, with eventual transfer for definitive care, is often required at non-transplant centers. Transfer for definitive care, in terms of bridge to transplant, may require ventricular assist device (VAD) placement at the primary institution or at the transplant center. Review of consecutive single transplant center referrals was conducted to decipher optimal management. From January 1997 to December 2000, 104 patients were transferred to the University of Pennsylvania Heart Failure/Transplant Service. Most were transferred from active cardiac surgical programs, with 56 patients having post-cardiotomy failure at the primary site. A VAD was placed in procedures done at the outside hospital (OSH) in 28 patients, most commonly (60%) an Abiomed device. Of the 76 patients that received a VAD at the transplant center (TxpC), 86% received a TCI or Thoratec device. Biventricular support was required in 34 patients. Overall survival was 57%, with 54 patients bridged to transplantation and 5 patients undergoing recovery. Patients having a VAD placed at the OSH had a 32% (9 of 28) survival, whereas at the TxpC survival was 65% (45 of 76) (p < 0.05). Mid-term follow-up showed that all 5 patients weaned are presently alive, and 52 patients are alive at >1-year post-transplant. The most common cause of death was multi-system organ failure (19 of 45), followed by major neurologic event (15 of 45). Infection was the cause of death in only 6 patients. Left ventricular failure can be treated by emergent VAD placement. Overall survival is substantial if these patients are referred to a transplant center with multiple options. In contrast to previous reports, survival rates may be improved by earlier referral, before VAD placement at non-transplant centers and use of a VAD with longer-term capability.     

Mechanical circulatory assistance after heart transplantation

From October 1985 through December 1989, 92 heart transplant procedures were performed in 89 patients. Nine patients (aged 19 to 66 years; 7 male, 2 female) required mechanical circulatory support after transplantation because of primary idiopathic organ failure (n = 2), implant difficulty (2), poor organ quality (2), or acute right heart failure (3). Devices used included the intraaortic balloon pump (6), centrifugal right ventricular assist device (2), left ventricular assist (1), biventricular assists (2), and total artificial heart (1). Two patients required multiple devices. One patient underwent retransplantation. Implant time ranged from 1 to 18 days. One early death occurred owing to right heart failure 6 days after transplantation, 7 hours after removal of a right ventricular assist device, for an overall mortality of 11%. The remaining 8 patients are alive 4 months to 28 months after transplantation. The actuarial 1-year survival of 89% +/- 10% compares well with the survival of 87% +/- 4% for the entire transplant group. All surviving patients are in functional class I. Echocardiographic examination in all patients revealed left ventricular ejection fraction to be normal in 7 and depressed in 1. Extending the criteria for organ donors or difficulty with the implant procedure can lead to early organ failure, which may be reversible with circulatory assistance allowing excellent survival.     

Risk analysis in patients bridged to transplantation

Background. Efforts to predict mortality in bridge to cardiac transplant patients have concentrated on pre-ventricular assist device (VAD) status. To more fully identify factors influencing survival to transplant, we reviewed the preoperative and postoperative VAD courses of 105 bridge to transplant patients.

Methods. Sixty-four parameters (34 pre-VAD, 30 post-VAD), including hemodynamics, complications, and evaluations of major organ function were examined and analyzed.

Results. Thirty-three patients (31%) died on VADs and 72 were transplanted. There were two posttransplant operative deaths (3%). By univariate analysis 23 of 64 factors were significant. These 23 factors were entered into a stepwise logistic regression analysis to identify predictors of survival to transplant. Four factors, including pre-VAD intubation (p < 0.005), cardiopulmonary bypass (CPB) time during VAD insertion (p < 0.0001), mean pulmonary artery pressure (first postoperative day after VAD) (p < 0.0002), and highest post-VAD creatinine (p < 0.01) were independent predictors of transplantation.

Conclusions. Other than the need for intubation, pre-VAD variables were of little value in predicting survival to transplant. Problems during VAD insertion (long CPB time) and post-VAD renal insufficiency were independent predictors. Severe complications that developed during the interval of VAD support, including cerebrovascular accident, bleeding and infection, were surprisingly not predictors for transplantation.     

Ventricular assist device support in children and adolescents with heart failure: the Children's Medical Center of Dallas experience

Children with heart failure unresponsive to medical therapy are left with few options for survival. Ventricular assist devices (VADs) are life-saving options for such patients, allowing for bridge to transplantation or cardiac recovery. Retrospective review of cases from May 2006 to October 2010 was undertaken. Fourteen patients underwent implantation of VADs for refractory heart failure. Mean age was 9 years (range 1-17 years), and weight was 41 kg (range 9.7-71 kg). Indications for support: end-stage cardiomyopathy (n = 8), myocarditis (n = 3), univentricular failure (n = 2), and congenital heart disease/postcardiotomy (n = 1). Level of limitation at time of implant included critical cardiogenic shock in six (43%) and progressive decline in eight (57%). Extracorporeal membrane oxygenation was used as a bridge to VAD in five (36%) patients. Preimplant variables: 86% of patients requiring mechanical ventilation (mean 10.3 days), hyperbilirubinemia in 75%, and acute renal insufficiency in 79%. Device selection was systemic VAD in 11 (79%) and biventricular assist device in three (21%). Berlin Heart EXCOR was used in eight patients, while six patients received a Thoratec implantable VAD or paracorporeal VAD. Mean duration of support was 68 days (range 8-363 days). Overall survival was 79%. Ten patients (71%) were successfully bridged to transplantation, three (21%) died while on a device, one remains on support, and no patients were weaned from VAD. Children supported for single ventricle heart failure had a 50% survival with none currently bridged to transplantation. Complications included bleeding requiring reoperation in 21% (n = 3), stroke in 29% (n = 4), and driveline infections in 7% (n = 1). In two patients, a total of six pump exchanges were performed for thrombus formation. Survival for pediatric patients of all ages is excellent using current device technology with a majority of patients being successfully bridged to transplantation. Morbidity is acceptably low considering the severity of illness. Significant challenges exist with long-term extracorporeal support due to lack of donor availability and the high incidence of preformed alloantibodies especially in the failing single ventricle.     

Current Status of Heart Assist and Replacement in Taiwan

Abstract: The first clinical application of intraaortic balloon pumps (IABP) in Taiwan was in 1976 to treat post-cardiotomy cardiogenic shock. It is now the most commonly used circulatory assist. From 1991 to 1995, 186 patients received IABP support with an overall mortality rate of 41.9%. The male patients had the best survival rate, 67%, after coronary artery bypass grafting. The first extracorporeal membrane oxygenation (ECMO) was in 1987 to treat intractable heart failure caused by severe acute rejection after heart transplantation. Because of poor outcome, patients only received ECMO sporadically during the past years. From November 1994 to November 1995, 30 patients received ECMO support with 50% of them eventually weaned from ECMO and 27% discharged. For short-term support or emergency rescue, ECMO was a good choice. When long-term support was required, the ventricular assist device (VAD) was a more suitable assist. One patient who received Thermedics VAD developed right heart failure and finally died of sepsis and multiple organ failure. VAD should be implanted before the secondary organ failure. The first successful clinical heart transplantation in Taiwan was performed on July 17, 1987. From 1991 to 1995, 102 patients underwent heart transplantation. The operative mortality was 3.9%, and the 1 and 5 year actuarial survival rates were 86 ± 3% and 77 ± 5%, respectively. To improve the success rate of clinical heart transplantation, organ donation should be encouraged.     

Selection of candidates for a ventricular assist device as a bridge to heart transplantation

This study was undertaken to see how many people could receive the ventricular assist device (VAD) as a bridge to heart transplantation and to get selection criteria of the recipient. From January 1984 to December 1987, 9916 patients were admitted to our institute and 399 cases of them were dead. All dead cases were examined in terms of age, heart disease, other organ function, infection, and so on. There were 42 possible candidates for VAD, 31 men and 11 women. The average age was 50 years with a range from 22 to 63 years. Ten cases (23.8%) of them had the indication for VAD bridge to transplantation. The criteria for transplantable patients included the following three categories: I) Cardiogenic shock: Irreversible left or double ventricular failure with or without life-threatening dysrhythmia during IABP therapy--4 cases. II) End-stage valvular heart disease; Operation under VAD stand-by--2 cases. III) Postoperative refractory ventricular pump failure: Failure to wean from assist circulation after IABP trial or sustained ventricular failure under IABP support--4 cases. It was indicated that continuous precise evaluation of the deteriorating hemodynamics and the intensive care for major organ functions (renal, pulmonary, neurologic, hepatic, coagulation, etc.) were important to select the candidate for VAD bridge to heart transplantation.     

Adjustable Model of Chronic Left Ventricular Dysfunction

Background. As an adjunct to the development of skeletal muscle-powered left ventricular assist devices, an adjustable model of chronic left ventricular failure was developed.

Methods. Implantation of a left ventricular balloon to induce heart failure was accomplished via left thoracotomy. Upon recovery, left ventricular failure was simulated by manipulation of left ventricular balloon volume to chronically raise left atrial pressure.

Results. Left atrial pressure increased from a baseline of 9.3 ± 0.7 mm Hg to 18.5 ± 1.2 mm Hg, 20.2 ± 1.8 mm Hg, and 26.0 ± 1.2 mm Hg by the 2nd, 6th, and 10th postoperative week, respectively. Cardiac index declined from a baseline of 4.4 ± 0.3 L · min⁻¹ · m⁻², reaching stability by the 8th postoperative week at 3.0 ± 0.4 L · min⁻¹ · m⁻². Stroke volume index declined from 1.12 ± 0.1 mL · kg⁻¹ · beat⁻¹ to 0.60 ± 0.1 mL · kg⁻¹ · beat⁻¹ by the 10th postoperative week. Mean survival was 75 ± 7 days. Causes of death included left ventricular failure, thromboembolism, and euthanasia.

Conclusions. This method of simulating chronic left ventricular dysfunction proved to be stable and adjustable and has been useful in the development of ventricular assist systems.     

Management of Prosthetic Valves during Ventricular Assist Device Implantation

Abstract Background: An increasing number of patients requiring ventricular assist devices (VAD) have had previous valvular corrections, including valve repair and valve replacement with mechanical or bioprosthetic valves. The operative and peri‐operative management of these patients has been varied. Methods: A retrospective study of VADs between January 1994 and June 2008 revealed 10 patients with previous prosthetic valves requiring management during and after VAD placement. Three patients were supported postcardiotomy after valve surgery. Two patients were supported due to cardiogenic shock postoperatively. Four patients were supported as a bridge to transplantation. One patient was supported as a destination therapy (DT). Results: The mitral, valve was left untreated during VAD implantation regardless of valve repair or replacement. For aortic valves, the mechanical aortic valve was replaced with tissue valve in two patients and left untreated in one case. One patient had tricuspid valve repair previously and was left untouched. All patients with prosthetic valves in aortic, mitral and tricuspid position during VAD support received anticoagulation therapy. There were four deaths, and four went on to transplantation. One patient was weaned from VAD and discharged from the hospital. One patient received HeartMate I as DT. The most common causes of death were multisystem organ failure (MSOF) and sepsis. One patient had a thromboembolic event. Conclusions: The survival rate of 60% is encouraging when compared to overall survival rates. The most common cause of death was MSOF. Patients with prosthetic valves may be safely managed during VAD support. (J Card Surg 2010;25:601‐605)     

Surgical procedures for patients receiving mechanical cardiac support

Mechanical cardiac support devices are used for patients with cardiopulmonary failure. We reviewed our institutional experience with noncardiac surgical procedures (NCPs) in patients supported by ventricular assist devices (VADs, n = 198) or extracorporeal membrane oxygenation (ECMO, n = 165) between July 1998 and June 2010. In total, 64 NCPs were performed in 55 VAD patients and 14 NCPs in 14 ECMO patients. Thirty-day mortality was higher for the VAD compared with the ECMO group (25 vs 86%; P < 0.001) and was greater for emergent compared with nonemergent procedures (58 vs 19%; P < 0.001). Excluding tracheostomy, no patients died within 30 days of a nonemergent procedure. Kaplan-Meier survival showed a trend toward worse survival after NCP in ECMO patients, but NCP did not alter survival in VAD patients. Fewer VAD patients were bridged to heart transplantation when NCP was required, and time from device implantation to transplant was significantly longer than for patients without NCP. In summary, this is the largest series of NCPs on VAD support and the only series on ECMO. Mortality is substantial for ECMO patients. Selected procedures can be performed safely in VAD patients but will delay heart transplantation.