Thrombosis of mitral valve bioprostheses in patients requiring circulatory assistance

Early acute thrombosis of bioprosthetic mitral valve presenting with cardiogenic shock

Early thrombosis of bioprosthetic mitral valves is an extremely rare occurrence. We present an unusual case of a patient with polycythemia presenting with cardiogenic shock, secondary to acute thrombosis of a bioprosthetic mitral valve which was placed 14 months prior to presentation. Our report also reviews predisposing factors and treatment options for bioprosthetic mitral valve thrombosis.

Biological mitral valve prosthesis in a patient supported with a permanent left ventricle assist device

Mitral valve pathology, especially status postvalve replacement (biological or mechanical), remains challenging in patients suffering from end-stage heart failure and undergoing left ventricular assist device (LVAD) placement due to several factors (potential source for thromboembolic complications, risk for structural deterioration of the biological prosthesis leading to stenosis, and inadequate LVAD preload). We report a case of long-term LVAD support in a patient with a previously implanted biological mitral valve prosthesis. During LVAD insertion, the valve was left in place, and it functioned well until the death of the patient 3 years later. The patient remained free of any valve-related complications.

Surgical treatment of early acute thrombosis of mechanical mitral prosthesis

Prosthetic valve thrombosis is a rare but life threatening complication of mechanical heart valve prosthesis. A 44-year-old woman diagnosed with rheumatic heart disease with severe mitral valve stenosis, moderate tricuspid valve insufficiency, and atrial fibrillation underwent transseptal mitral valve replacement and tricuspid valvuloplasty in our department. Heparin and warfarin were routinely used postoperatively. Although the international normalized ratio (INR), activated partial thromboplastin time ratio, and platelet count were satisfactory, the patient presented with severe dyspnea suddenly 10 days after discharge; echocardiogram showed that the prosthetic posterior leaflet was immobile. The patient suffered cardiac arrest suddenly during the examination and cardiopulmonary resuscitation was carried out successfully. Emergent surgery was performed, confirming the prosthetic valve thrombosis. The prosthetic valve was replaced with another mechanical prosthesis. The patient recovered smoothly and was discharged 14 days later with atrial fibrillation. During the 12-months follow-up period, her prosthetic valve and heart function were normal with INR around 3.0. This case highlights the need for awareness among clinicians for the possibility of valve thrombosis in the early postoperative period.

Successful management of multiple permanent pacemaker complications--infection, 13 year old silent lead perforation and exteriorisation following failed percutaneous extraction, superior vena cava obstruction, tricuspid valve endocarditis, pulmonary embolism and prosthetic tricuspid valve thrombosis

A 59 year old man underwent mechanical tricuspid valve replacement and removal of pacemaker generator along with 4 pacemaker leads for pacemaker endocarditis and superior vena cava obstruction after an earlier percutaneous extraction had to be abandoned, 13 years ago, due to cardiac arrest, accompanied by silent, unsuspected right atrial perforation and exteriorisation of lead. Postoperative course was complicated by tricuspid valve thrombosis and secondary pulmonary embolism requiring TPA thrombolysis which was instantly successful. A review of literature of pacemaker endocarditis and tricuspid thrombosis along with the relevant management strategies is presented. We believe this case report is unusual on account of non operative management of right atrial lead perforation following an unsuccessful attempt at percutaneous removal of right sided infected pacemaker leads and the incidental discovery of the perforated lead 13 years later at sternotomy, presentation of pacemaker endocarditis with a massive load of vegetations along the entire pacemaker lead tract in superior vena cava, right atrial endocardium, tricuspid valve and right ventricular endocardium, leading to a functional and structural SVC obstruction, requirement of an unusually large dose of warfarin postoperatively occasioned, in all probability, by antibiotic drug interactions, presentation of tricuspid prosthetic valve thrombosis uniquely as vasovagal syncope and isolated hypoxia and near instantaneous resolution of tricuspid prosthetic valve thrombosis with Alteplase thrombolysis.

Mechanical mitral prosthesis with a short-term left ventricular assist device

Mechanical circulatory support with ventricular assist devices in patients with mechanical valvular prostheses may predispose to thromboembolic and hemodynamic complications. Conventional approaches to reduce these risks involve redo valve replacement to a bioprosthesis. Careful management of the ventricular assist device to allow flow across the prosthesis may obviate the need for redo valve replacement. Avoidance of further myocardial ischemia during redo valve replacement carries particular importance for patients in whom the aim is recovery. We report a successful outcome from retention of a mechanical mitral prosthesis during a 10-day period of mechanical circulatory support and review the pertinent literature.

Axial Flow Pump Support in a Marfan Patient With an Aortic Mechanical Heart Valve

The presence of a mechanical heart valve in the aortic position is usually considered a contraindication for the use of cardiac assist devices. Only a few cases with the combination of mechanical circulatory support and valve prostheses have been reported in the literature to date, and the experience is even more limited in the new generation of miniaturized axial flow pumps. We present a case report of a patient with a mechanical aortic heart valve who was successfully supported with a continuous flow pump and discuss the literature available on this problem. Further on, the patient was weaned from his ventricular assist device after 456 days of support.

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.

Ventricular assist device use with mechanical heart valves: an outcome series and literature review

BACKGROUND

Management of postcardiotomy cardiogenic shock with a ventricular assist device (VAD) is a common and accepted therapeutic option. However, VAD use in patients with mechanical heart valves (MHVs) is thought to carry an increased risk of thromboembolus. We report a series of 7 patients with combined VAD-MHV and review the literature.

METHODS

A retrospective review was performed on all patients who were supported with a ventricular assist device with a mechanical heart valve in place. A literature review was also performed from 1966 to 2000.

RESULTS

Seven patients were identified from April 1988 to June 2000 as having VAD support with a MHV. One thromboembolic event was documented in the 7 patients (14%). Five of the 7 patients (71%) underwent VAD explantation. Overall survival rate was 3 of 7 (43%). Causes of death included heart failure, renal failure, multisystem organ failure, adult respiratory distress syndrome, and cerebral hypoxia. All patients who died had support withdrawn at the request of the family. All patients discharged are currently alive with length of survival of 3, 26, and 84 months.

CONCLUSIONS

This study suggests that this population's rate of survival to discharge and risk of thromboembolus compare favorably to that of the general VAD population. We believe that anticoagulation can be managed as with any MHV patient and that flow rates can be kept slightly lower, which may encourage valve washing.

An unusual case of bioprosthetic mitral valve thrombosis

Bioprosthetic valve thrombosis and related embolism are considered extremely unlikely, thus allowing most patients to avoid long-term anticoagulation. There is, however, limited experience in the diagnosis and treatment of such a condition. We present the case of a patient with a porcine mitral bioprosthesis who presented with acute thrombosis with unusual echocardiographic features. A favorable outcome was observed after conventional anticoagulant treatment.

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 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 tricuspid 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.