A case series of patients with left ventricular assist devices and concomitant mechanical heart valves

Mechanical heart valves left in situ at the time of left ventricular assist device (LVAD) implantation are thought to potentially increase the risk of thromboembolism. Recommendations exist to replace dysfunctional mechanical mitral valves and any mechanical aortic valves at the time of LVAD implantation. Due to potential increases in cardiopulmonary bypass time and associated comorbidities with valve replacement, leaving a functional mechanical valve in place at LVAD implantation has been suggested to be a safe option. We retrospectively reviewed all patients with prior mechanical mitral or aortic valves undergoing LVAD implantation at our center between 2012 and 2017. Echocardiograms were read by a single cardiologist to assess for mechanical valve dysfunction. We identified 15 patients. Five patients had major bleeding requiring transfusion. On follow-up, 2 patients had hemorrhagic stroke and 2 had transient ischemic attach/ischemic stroke. In addition, 2 patients had LVAD thrombosis and 2 patients had LVAD driveline malfunction. Mild mechanical valve regurgitation was identified on follow-up echocardiograms of 2 patients. Rate of complications in patients with mechanical valves undergoing LVAD implantation was comparable to that reported for the general LVAD population. Leaving a functional mechanical valve in place at the time of LVAD implantation could be a reasonable alternative to valve replacement. More data are required to further guide patient care in these individuals.     

Surgical management of valvular disease in patients requiring left ventricular assist device support

BACKGROUND: Success with long-term implantable left ventricular assist devices (LVAD) has led to increased use in patients previously thought to be unsuitable for mechanical circulatory assistance. Patients with preexisting or newly diagnosed valvular disease have been traditionally excluded from device placement. The purpose of this study was to review our experience with LVAD support in patients with valvular disease and to develop a management algorithm for these difficult patients. METHODS: We reviewed the clinical records of 199 consecutive patients who received the ThermoCardiosystems, Inc, HeartMate Pneumatic or Vented Electric LVAD. There were 18 patients (9%) who required surgical management of native or prosthetic valvular disease during LVAD implantation. RESULTS: Suture or patch closure of the aortic valve was performed in 6 patients, aortic valve plication and repair in 1 patient, mitral valve repair in 4 patients, and tricuspid valve annuloplasty in 5 patients. Two patients with mechanical mitral valve prostheses were treated with postoperative warfarin anticoagulation. Fifteen of the 18 patients with valvular pathology survived the immediate postoperative period (17% mortality). Eleven patients have either undergone transplantation or continue to be supported with an LVAD (61%). Operative mortality in LVAD patients without concomitant valve repair was 18% (n = 33) with a late mortality of 7% (n = 13). Seven of these late deaths occurred in patients who received a device as destination therapy. In the remaining 6 patients, the cause of death was sepsis (n = 2), multisystem organ failure (n = 2), driveline rupture (n = 1), and massive gastrointestinal bleed (n = 1). CONCLUSIONS: Preexisting native or prosthetic valve pathology does not increase the immediate perioperative risk of LVAD insertion; however, these patients continue to pose a challenge for postoperative management while awaiting transplantation.     

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.     

Direct transaortic transcather valve-in-valve implantation into a mechanical aortic valve prosthesis during left ventricular assist device implantation: description of a surgical technique

The presence of a mechanical aortic valve prosthesis is considered a relative contraindication for left ventricular assist device implantation (LVAD) due to the occurrence of thromboembolic events. Five patients were operated on for LVAD implantation with status post mechanical aortic valve implantation (n = 3 with status post Bentall procedure). After removal of the leaflets, a transcatheter balloon-expandable valve was placed within the mechanical ring in all patients. Three patients were discharged from hospital with a maximum follow-up of 3.3 years. Transaortic transcatheter valve implantation into a mechanical aortic valve during LVAD implantation is a feasible option. It reduces operative times and might also prevent thromboembolic events.     

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.     

Mitral valve replacement in the first 5 years of life

Between 1976 and 1986, 19 children aged 1 month to 5 years underwent replacement of the mitral (systemic atrioventricular) valve. Indications for valve replacement included isolated congenital mitral stenosis (n = 2), valve dysfunction associated with a more complex procedure (n = 15), and failed valvuloplasty (n = 2). Seven different valve types were used; nine were mechanical valves and ten were bioprosthetic valves. There were 6 hospital deaths (32%; 70% confidence limits, 20% to 47%). Among the 13 survivors there were 3 late deaths at a mean of 14 months after operation. The late deaths were unrelated to valve malfunction. Thromboembolic events occurred in 2 patients, both with mechanical valves. One minor bleeding complication occurred among 10 patients on a regimen of Coumadin (crystalline warfarin sodium). Five patients, all with bioprostheses, required a second valve replacement. Indications for reoperation included prosthetic valve regurgitation (n = 1) and calcific stenosis (n = 4). No early or late deaths occurred after second valve replacement. Survival was 51% +/- 12% (standard error) at 112 months after valve replacement. Analysis failed to identify age, weight, sex, previous operation, underlying cardiac lesion, or prosthesis size and type as significant risk factors for mortality. Mechanical valves had a lower reoperation rate compared with bioprostheses. These data suggest that although mitral valve replacement within the first 5 years of life is associated with a high operative and late mortality, satisfactory long-term palliation for many patients can be achieved. Mechanical valves are superior to bioprosthetic valves, and offer the best long-term results.     

Total left ventricular outflow tract obstruction due to left ventricular assist device-induced sub-aortic thrombosis in 2 patients with aortic valve bioprosthesis.

This report describes 2 patients with an aortic bioprosthesis. Both patients developed total thrombotic occlusion of the sub-aortic left ventricular outflow tract consequent to insertion of a left ventricular assist device (LVAD). Replacing a mechanical valve with a bioprosthesis in patients receiving a left ventricular assist device offers no additional protection against thrombosis of the aortic prosthesis. Pericardial patching below the aortic prosthesis at the time of LVAD implantation may be performed, but will significantly impede or prohibit the native ventricle from ejecting blood and demonstrating any degree of recovery.     

Successful recovery and long-term survival following postcardiotomy (mitral valve replacement) cardiogenic shock by means of a left ventricular assist device

A 48-year-old woman who had had mitral regurgitation associated with hypertension and left ventricular hypertrophy underwent mitral valve replacement with a 29 mm xenograft. Following the uneventful procedure, she could not come off cardiopulmonary bypass for 6 times even with an aid of IABP and with re-replacement of the mitral valve using a 29 mm Duromedics prosthesis because of the fear of xenograft malfunction. A left ventricular assist device (LVAD) was then utilized with a resultant dramatic recovery from profound postcardiotomy cardiogenic shock, and cardiopulmonary bypass was successfully terminated. Postoperatively, her hemodynamics were maintained with a LVAD and IABP. Heparin was used to keep the prosthesis from blood clotting by monitoring the ACT. The heart recovered gradually from intraoperative myocardial damage and the LVAD was successfully removed at the 5th postoperative day. Postoperative cardiac catheterization studies showed decreases in left ventricular wall motion and ejection fraction, although improvements of pulmonary hypertension and left ventricular end-diastolic pressure at rest were observed. At present, 1 year and 9 months after the use of LVAD, she is leading nearly normal life of NYHA grade 1. Because of the excellent present clinical condition of this patient, the benefit of a LVAD in perioperative cardiogenic shock is stressed.     

Mechanical failure of the Bj?rk-Shiley valve. Incidence, clinical presentation, and management

The experience after implantation of 3,334 Bj?rk-Shiley valves over a 15 year period is described. With a 99.2% follow-up (covering 17,511 patient-years, mean follow-up time 6.3 years) and an autopsy rate of 75% among all fatalities, altogether 19 cases of mechanical failure were documented. There were no mechanical failures among the standard Delrin Bj?rk-Shiley valve (n = 271), the aortic standard Pyrolyte Bj?rk-Shiley (n = 739), or the Monostrut Bj?rk-Shiley valve (n = 377). One of the mitral standard Pyrolyte valves (n = 430) fractured. Among the 1,461 convexo-concave valves, 18 fractured (6/884 with an opening angle of 60 degrees and 12/577 with an opening angle of 70 degrees). The actuarial incidence of mechanical failure at 5 years was 0.6% (with an upper 95% confidence limit of 1.2%) for the 60 degree convexo-concave valve and 2.8% (upper 95% confidence limit of 4.4%) for the 70 degree convexo-concave valve (p less than 0.01). Two groups of valves were especially affected by this complication; the 23 mm aortic 60 degree convexo-concave valve (5 year actuarial incidence 2.2%, upper 95% confidence limit 4.7%) and the 29 to 31 mm mitral 70 degree convexo-concave valve (8.3%, upper 95% confidence limit 14.2%). The hazard function presently indicates a constant (60 degree convexo-concave) or decreasing (70 degree convexo-concave) tendency for mechanical failure. The time interval between the first symptom of mechanical failure and circulatory collapse was significantly (p less than 0.01) shorter after aortic failure than after mitral failure, and no patient with a fractured aortic prosthesis survived long enough to undergo reoperation. The incidence of mechanical failure among patients dying suddenly (but with an autopsy) was 9.6% (95% confidence limits 4.9%-16.6%), and most cases of sudden death were unrelated to the prosthesis. The management of patients with suspected mechanical failure is described. Prophylactic re-replacements are discussed but cannot be generally recommended at present.     

Mitral valvuloplasty with sutures used for aortic prosthesis implantation

BACKGROUND: The purpose of this study was to analyze surgical treatment for aortic valve lesions with coexisting mitral regurgitation (MR). METHODS: Seventy-five patients were divided into two groups according to intensity of MR (group 1, MR less than or equal to II; group 2, MR greater than or equal to II/III). There were two control groups (control 1, only patients with implantation of aortic valve; control 2, patients with implantation of both aortic and mitral prostheses). During implantation of a mechanical aortic prosthesis, the same suture for fixation of a mechanical prosthesis and for suspension of mitral commissural regions and lifting the base of anterior mitral cusp was used. RESULTS: In all patients, no early death occurred. There were two late deaths, one due to endocarditis, and the other to heart failure. All patients from both groups had decreased MR. Selected echocardiographic parameters improved: end diastolic and end systolic diameter and ejection fraction in group 2 improved in proportion to patients in whom mitral valves were implanted (control 2). CONCLUSIONS: Simultaneous suspension of the mitral commissure area during mechanical aortic prosthesis implantation reduces associated MR. This technique seems to be efficient during implantation of aortic prostheses in patients with coexisting MR.     

Intravascular hemolysis in patients with new-generation prosthetic heart valves: a prospective study

OBJECTIVE: A prospective clinical study was designed to assess the frequency and severity of intravascular hemolysis in patients with new-generation, normally functioning prosthetic heart valves. METHODS: Hemolysis was evaluated in 172 patients with a mechanical prosthesis (53 CarboMedics and 119 Sorin Bicarbon) and in 106 patients with a bioprosthesis (15 St Jude Medical Toronto, 19 Baxter Perimount, and 72 Medtronic Mosaic) in the aortic position, mitral position, or both. Aortic valve replacement was performed in 206 patients, mitral valve replacement in 59 patients, and double valve replacement in 13 patients. The presence of hemolysis was assessed on the basis of the level of serum lactic dehydrogenase and serum haptoglobin and the presence and amount of reticulocytes and schistocytes in the peripheral blood. Severity of intravascular hemolysis was estimated on the basis of serum lactic dehydrogenase. Clinical, echocardiographic, and hematologic evaluations were performed 1, 6, and 12 months after discharge. RESULTS: None of the 278 patients experienced decompensated anemia, whereas at 12 months, mild subclinical hemolysis was identified in 49 patients, 44 (26%) with a mechanical prosthesis and 5 (5%) with a bioprosthesis (P <.001). At multivariate analysis, independent predictors of the presence of subclinical hemolysis were mitral valve replacement (P <.001), use of a mechanical prosthesis (P =.002), and double valve replacement (P =.02). Frequency of hemolysis in patients with stented aortic bioprostheses was 3%, whereas it was absent in those with stentless valves. Among mechanical valve recipients, double versus single valve replacement (P =.04) and mitral versus aortic valve replacement (P =.05) were correlated with the presence of hemolysis; double valve recipients also showed a more severe degree of hemolysis (P =.03). In patients with a Sorin Bicarbon prosthesis, hemolysis was less frequent (22% vs 34%, P =.09) and severe (P <.001) than in those with a CarboMedics prosthesis. CONCLUSIONS: In normally functioning prosthetic heart valves, subclinical hemolysis is a frequent finding. A low incidence of hemolysis is found in stented biologic prostheses, and it is absent in stentless aortic valves. Modifications of valve design may contribute to minimize the occurrence of hemolysis in mechanical prostheses.     

Prosthetic valve replacement in children

Between 1975 and 1998, 27 patients aged 3 months to 14 years underwent replacement of the aortic, mitral, tricuspid, and pulmonary valves. Five different types of prosthetic valves were used; three were mechanical valves and two were bioprosthetic valves. There were 3 hospital deaths. Among the 24 survivors there were 4 late deaths. Arrhythmia requiring pacemaker implantation occurred in 2 cases after AVR and TVR. Thromboembolic events occurred in 3 patients, all with mechanical valves in pulmonary position. Infective endocarditis occurred in 1 patient after PVR with a mechanical valve. No bleeding complication occurred among the patients on a regimen of Coumadin and Dipyridamole. Two patients, both with Hancock bioprosthesis, required a second valve replacement on account of severely calcified changes. Mechanical valves in left side heart had a satisfactory long-term performance. One patient who had undergone MVR for congenital parachute mitral valve received reoperation for growth. A larger sized prosthetic valve should be used at the first replacement, and special procedures including supra-annular positioning or annular augmentation are recommended for MVR or AVR respectively.     

Comparison of survival after mitral valve replacement with biologic and mechanical valves in 1139 patients

OBJECTIVE: We sought to compare 10-year survival in patients after mitral valve replacement with biologic or mechanical valve prostheses. METHODS: Retrospective survival analysis was performed on data from 1139 consecutive patients older than 18 years of age undergoing mitral valve replacement with Carpentier-Edwards (n = 495; Baxter Healthcare Corp, Irvine, Calif) or St Jude Medical (n = 644; St Jude Medical, Inc, St Paul, Minn) prostheses. RESULTS: The 10-year survival was not statistically different between the patients receiving Carpentier-Edwards valves and those receiving St Jude Medical valves (P =.16). Adjusted survival estimates at 2, 5, and 10 years were 82% +/- 2% (95% confidence intervals, 79%-85%), 69% +/- 2% (95% confidence intervals, 64%-73%), and 42% +/- 3% (95% confidence intervals, 37%-48%), respectively, for the Carpentier-Edwards group and 83% +/- 2% (95% confidence intervals, 80%-86%), 72% +/- 2% (95% confidence intervals, 69%-76%), and 51% +/- 3% (95% confidence intervals, 45%-58%), respectively, for the St Jude Medical group. Predictors of worse survival after mitral valve replacement are older age, lower ejection fraction, presence of class IV congestive heart failure, coronary artery disease, renal disease, smoking history, hypertension, concurrent other valve surgery, and redo heart surgery. CONCLUSION: Choice of biologic or mechanical prosthesis does not significantly affect long-term patient survival after mitral valve replacement.     

Impact of Residual Mitral Regurgitation on Right Ventricular Systolic Function After Left Ventricular Assist Device Implantation

Significant mitral regurgitation (MR) is thought to decrease after left ventricular assist device (LVAD) implantation, and therefore repair of mitral valve is not indicated in current practice. However, residual moderate and severe MR leads to pulmonary artery pressure increase, thereby resulting in right ventricular (RV) dysfunction during follow‐up. We examined the impact of residual MR on systolic function of the right ventricle by echocardiography after LVAD implantation. This study included 90 patients (mean age: 51.7 ± 10.9 years, 14.4% female) who underwent LVAD implantation (HeartMate II = 21, HeartWare = 69) in a single center between December 2010 and June 2014. Echocardiograms obtained at 3–6 months and over after implantation were analyzed retrospectively. RV systolic function was graded as normal, mild, moderate, and severely depressed. MR (≥moderate) was observed in 43 and 44% of patients at early and late period, respectively. Systolic function of the RV was severely depressed in 16 and 9% of all patients. Initial analysis (mean duration of support 174.3 ± 42.5 days) showed a statistically significant correlation between less MR and improved systolic function of RV (P = 0.01). Secondary echocardiographic analysis (following a mean duration of support of 435.1 ± 203 days) was also statistically significant for MR degree and RV systolic dysfunction (P = 0.008). Residual MR after LVAD implantation may cause deterioration of RV systolic function and cause right‐sided heart failure symptoms. Repair of severe MR, in selected patients such as those with severe pulmonary hypertension and depressed RV, may be considered to improve the patient's clinical course during pump support.     

Experience with St. Jude Medical valve prosthesis in children. A word of caution regarding right-sided placement

Thirty-six children aged 6 months to 18 years, underwent insertion of 37 St. Jude Medical cardiac prostheses. In 20, the valve was placed in the aortic or mitral position, and in 16 in the pulmonary or tricuspid position. There was one (2.8%) hospital death. All patients received maintenance doses of salicylates and dipyridamole after the operation. Follow-up data are available for all patients for 12 to 24 postoperative months. There was no incidence of valve dysfunction or thromboembolic complication in any of the 20 patients with valves in the systemic (left) side of the circulation, and all manifested improvement in their functional class. In contrast, six (37%) of the 16 patients with valves in the pulmonary (right) side of the circulation developed dysfunction of the prosthesis 1 to 6 months after insertion. Prosthesis failure was associated with fibrous tissue growing into the struts, leading to leaflet immobilization. At 2 years, the actuarial functional life was 100% for mitral and aortic valves and 70% for pulmonary and tricuspid valves. The data illustrate the excellent hemodynamic function of the St. Jude Medical valve in children. The absence of thromboembolic complications warrant continued implantation of the prosthesis in the left side without warfarin anticoagulation therapy, but the high incidence of valve dysfunction in the pulmonary position does not justify its continued use in the right side.     

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.     

Influence of aortic valve replacement, prosthesis type, and size on functional outcome and ventricular mass in patients with aortic stenosis.

OBJECTIVES: Two years after surgery for severe aortic stenosis, we prospectively evaluated the influence of aortic valve replacement, as well as valve type (mechanical or stented biologic) and size, on functional status, left ventricular function, and regression of mass. METHODS: Patients who received either a mechanical (n = 95) or a biologic valve (n = 42) were studied by echocardiography before the operation and after 2 years. RESULTS: The percentage of patients with severe dyspnea decreased from 53% to 13% (P =.001). The cardiac index increased from mean 2.6 L/min per square meter (95% CI: 2.48-2. 72 L/min per square meter) to 3.1 L/min per square meter (95% CI: 2. 94-3.26 L/min per square meter; P =.001). The percentage of the patients with mild-to-moderate diastolic dysfunction decreased from 43% to 18% (P =.001). The left ventricular mass index was reduced by 42.4 g (95% CI: 35-50 g; P =.001). In comparison with biologic valves of the same size, mechanical valves produced a more pronounced reduction in mass index (overall difference 21.7 g; 95% CI: 37.1-6.4 g; P =.007) and a lower mean Doppler gradient (overall difference 4 mm Hg; 95% CI: 2-6 mm Hg; P =.0002). CONCLUSIONS: Patients undergoing aortic valve replacement had an improvement in functional status, as well as systolic and diastolic left ventricular function, and a reduction in left ventricular mass index, irrespective of prosthesis size and type. Mechanical valves are somewhat less obstructive than stented bioprosthetic valves of the same size. They are also associated with a concomitantly more pronounced reduction of left ventricular mass.     

TAVI for pure aortic valve insufficiency in a patient with a left ventricular assist device

We report transcatheter aortic valve implantation (TAVI) for pure aortic valve insufficiency in a patient with an otherwise normal aortic valve and a long-term left ventricular assist device (LVAD). An oversized 29-mm Edwards SAPIEN valve (Edwards Lifesciences, Irvine, CA) was implanted in the 21-mm native aortic valve annulus. Despite the complete absence of aortic calcifications, the prosthesis remained stably anchored inside the annulus. The reported experience demonstrates that TAVI is feasible even in patients with pure aortic valve regurgitation and can be a reasonable option in patients with aortic regurgitation after LVAD implantation.     

LVAD support in patients with bioprosthetic valves

The presence of mechanical or bioprosthetic valves has traditionally excluded patients from mechanical circulatory support. However, several centers have now developed algorithms for the surgical management of native or prosthetic valve disease in patients requiring left ventricular assist device insertion. We report adverse events associated with bioprosthetic valves in the mitral and tricuspid positions in 2 patients who received long-term mechanical support. We recommend anticoagulation for all patients with prosthetic valves in the mitral or tricuspid position to avoid thromboembolism, inflow conduit occlusion, or valvular incompetence.     

Development of anti-major histocompatibility complex class I or II antibodies following left ventricular assist device implantation: effects on subsequent allograft rejection and survival.

BACKGROUND: Previous reports have indicated that antibodies to HLA class I or II antigens develop in approximately 60% of patients following left ventricular assist device (LVAD) implantation, subsequent rates of allograft rejection are higher, and survival is adversely affected. METHODS: We performed an analysis of the incidence of antibody development to HLA class I or II antigens by panel reactive antibody (PRA) screening following implantation of the HeartMate LVAD in 38 patients from October 1, 1996 to March 1, 2000 (6 LVAD deaths excluded from study). The occurrence of vascular or cellular rejection of International Society of Heart and Lung Transplantation grade > or = 3A, as determined by endomyocardial biopsy following heart transplantation (HTX), were compared for patients with (n = 32, LVAD group) or without (n = 68, control group) preoperative LVAD support. RESULTS: After LVAD implantation, 9 patients (28%) in the LVAD group developed IgG antibodies to class I (n = 3), class II (n = 5), or both antigens (n = 1) with PRA > 10%. The remaining 23 patients (72%) had either no detectable IgG antibody development or IgG antibody development with PRA < 10%. At the time of HTX, only 4 patients in the LVAD group had persistent PRA > 10%. Only 3 patients (4%) in the control group had PRA > 10% at the time of HTX. The incidence of patients free from rejection at 6 and 12 months was 62% and 44% for the control group, and 49%, and 40% for the LVAD group, respectively (p not significant). The mean linearized rate plus or minus standard deviation of allograft rejection from 0 to 6 months and 7 to 12 months was 0.13 +/- 0.21 and 0.09 +/- 0.14 episodes a month, respectively, for patients with no LVAD support, and 0.17 +/-.25 and 0.06 +/- 0.1 episodes a month, respectively, for those with LVAD support (p = not significant). Post-transplantation survival at 1 and 2 years was 90% and 90%, respectively, for the control group, and 97% and 92%, respectively, for the LVAD group (p not significant). CONCLUSION: Patients with LVAD support before HTX do not appear to be at increased risk for significant allograft rejection in the first year or for death within the first 2 years after transplantation.