Louis E. Samuels

Annexin-V imaging for noninvasive detection of cardiac allograft rejection

Heart transplant rejection is characterized pathologically by myocyte necrosis and apoptosis associated with interstitial mononuclear cell infiltration. Any one of these components can be targeted for noninvasive detection of transplant rejection. During apoptotic cell death, phosphatidylserine, a phospholipid that is normally confined to the inner leaflet of cell membrane bilayer, gets exteriorized. Technetium-99m-labeled annexin-V, an endogenous protein that has high affinity for binding to phosphatidylserine, has been administered intravenously for noninvasive identification of apoptotic cell death. In the present study of 18 cardiac allograft recipients, 13 patients had negative and five had positive myocardial uptake of annexin. These latter five demonstrated at least moderate transplant rejection and caspase-3 staining, suggesting apoptosis in their biopsy specimens. This study reveals the clinical feasibility and safety of annexin-V imaging for noninvasive detection of transplant rejection by targeting cell membrane phospholipid alterations that are commonly associated with the process of apoptosis.

The RECOVER I: A multicenter prospective study of Impella 5.0/LD for postcardiotomy circulatory support

OBJECTIVES Cardiogenic shock after cardiac surgery is accompanied by a high mortality rate. Early institution of hemodynamic support with a versatile, easy to insert left ventricular assist device might help bridge patients to recovery or to the next therapy, and improve the outcomes. METHODS Patients developing cardiogenic shock or low cardiac output syndrome after being weaned off cardiopulmonary bypass were enrolled in a prospective single-arm feasibility study (RECOVER I). The primary safety endpoint was the frequency of major adverse events (death, stroke) at 30 days or discharge, whichever was longer. The primary efficacy endpoint was survival of the patient to implementation of the next therapy, which included recovery at 30 days after device removal and bridge-to-other-therapy. RESULTS Sixteen patients provided informed consent and were enrolled in the study. Hemodynamics improved immediately after the initiation of mechanical support: cardiac index, 1.65 versus 2.7 L/min/m(2) (P = .0001); mean arterial pressure, 71.4 versus 83.1 mm Hg (P = .01); and pulmonary artery diastolic pressure, 28.0 versus 19.8 mm Hg (P < .0001). The pump provided an average of 4.0 ± 0.6 L/min of flow for an average duration of 3.7 ± 2.9 days (range, 1.7-12.6). The primary safety endpoint occurred in 2 patients (13%; 1 stroke and 1 death). For the primary efficacy endpoint, recovery of the native heart function was obtained in 93% of the patients discharged, with bridge-to-other-therapy in 7%. Survival to 30 days, 3 months, and 1 year was 94%, 81%, and 75%, respectively. CONCLUSIONS The use of the Impella 5.0/left direct device is safe and feasible in patients presenting with postcardiotomy cardiogenic shock. The device was rapidly inserted, enabled early support, and yielded favorable outcomes.

'Routine' radiologic evaluation of the thoracolumbar spine in blunt trauma patients: a reappraisal.

A retrospective review of 756 blunt trauma cases at a level I trauma center was conducted to determine the role of thoracolumbar (TL) spine roentgenograms in the management of asymptomatic patients. Thoracolumbar spine films were obtained on 106 patients. The charts from 99 patients were available for thorough review. Fifty-five patients had negative clinical evidence of TL spine injury; all of these (100%) had negative radiographic evidence of fracture or dislocation on the TL spine films. Twenty-four patients had positive clinical evidence of TL spine injury; 14 (58%) had corresponding radiographic evidence of TL spine injury. Of the 20 patients in whom the clinical examination was equivocal, one (5%) had radiographic evidence of TL spine injury. We conclude that physical examination is reliable for assessing the TL spine, and that in the absence of clinical evidence of injury, TL spine films are unnecessary. In patients with equivocal examinations, TL spine films should be obtained because 7% (one of 15) of the injuries were identified in this group.

The AbioCor implantable replacement heart

The AbioCor implantable replacement heart (IRH) is the first available totally implantable artificial heart. We recently initiated a multicenter trial of this device in patients with severe, irreversible biventricular failure. Patients who were not candidates for other therapies, including transplantation, were evaluated. All candidates were adults with inotrope-dependent biventricular failure, whose 30-day predicted mortality was higher than 70%. A three-dimensional computerized fit study predicted fit of the AbioCor thoracic unit in all recipients. At operation, the internal battery controller and transcutaneous energy transfer unit were placed. The AbioCor thoracic unit was placed in an orthotopic position after incision of the ventricals. There were 2 intraoperative deaths (due to intraoperative bleeding or aprotinin reaction). Four late deaths were recorded, 1 from multisystem organ failure and 3 cerebrovascular accidents. Autopsy revealed thrombus on the atrial struts of the 3 patients with cerebrovascular accident. Blood pumps and valves were clean on all patients. Significant morbidity was observed, primarily related to preexisting severity of illness. However, 3 patients recovered to the point of being able to take multiple trips outside of the hospital. Two patients were discharged from the hospital, with 1 patient being discharged home for more than 7 months. No significant device malfunctions or multi-system organ failure device-related infections were noted. The AbioCor IRH may be effective therapy for patients with end-stage heart failure. Many milestones have been achieved in the initial trial in humans, including the successful discharge of a patient to home and no significant device malfunctions. The occurrence of stroke is likely related to the presence of thrombus on the atrial struts and may be decreased as these atrial struts have been removed for future clinical implants.

Use of the AB5000™ Ventricular Assist Device in Cardiogenic Shock After Acute Myocardial Infarction

BACKGROUND The mortality rate of patients experiencing acute myocardial infarction (AMI) complicated by cardiogenic shock remains high. After conventional therapies have failed, ventricular assist devices (VADs) have been used to bridge patients to recovery or transplantation. METHODS A voluntary US registry was established to track all patients implanted with the AB5000 VAD. We report the results of the first 100 patients in the registry with the indication of AMI cardiogenic shock. Data were retrospectively reviewed for demographics, preimplant condition, surgical techniques, and outcomes. Survival was assessed at 30 days after VAD explant or at discharge. Myocardial recovery (subset of survival) was defined as satisfactory unassisted native cardiac function for 30 days after VAD explant or at discharge. RESULTS Forty patients (40%) survived to 30 days after VAD explant or discharge of the first 100 patients. Of the survivors, 63% (n = 25) experienced myocardial recovery. Patients who recovered required an average of 25 +/- 22 days of VAD support. The estimated survival after explant for the recovery patients at 2 years after VAD explant was 78%. CONCLUSIONS Results from this nationwide registry suggest that VADs can restore normal hemodynamics and support recovery of native cardiac function in the majority of survivors when conventional therapies fail. However, a longer duration of support than previously recognized may be required. In the absence of clinical guidelines, early aggressive use of VAD support in AMI complicated by cardiogenic shock may improve outcomes, and recovery of native cardiac function should always be the primary goal.

Cardiac Surgery in Nonagenarians

Abstract Objectives and Background: The purpose of this study was to document our initial experience with patients 90 years of age and older and to determine whether cardiac surgery is justified in this age group. Cardiac surgery in octogenarians has proven to be a successful and worthwhile procedure. A small group of nonagenarians with severe coronary artery disease (CAD) and aortic valve disease refractory to medical therapy have been considered for surgery. Methods: Fourteen patients aged 90 or more underwent cardiac surgery for symptomatic CAD or aortic valvular disease refractory to medical therapy. Eight patients underwent isolated coronary artery bypass grafting (CABG) and six patients underwent aortic valve replacement (AVR). All patients were in NYHA Class IV preoperatively. Results: Hospital mortality occurred in one patient (7%). Hospital morbidity occurred in 10 patients (71%) and included 7 cardiac, 5 neurological, 1 gastrointestinal, 1 infectious, and 1 pulmonary event. All survivors left the hospital symptomatically improved. The mean length of stay was 26 days. Four CABG patients went on to die at a mean of 2 years and 2 months, and 3 remain alive at a mean of 2 years and 4 months. Three AVR patients expired at a mean of 3 years and 4 months, and 3 remain alive at 4 years and 1 month. Conclusions: Cardiac surgery in carefully selected nonagenarians is justified and can be performed with acceptable results.

Coronary Artery Bypass Surgery in Nonagenarians

As the number of nonagenarians increases yearly in the United States, surgeons will be asked more often to evaluate the possibility of intervention for coronary artery disease in this age group. The purpose of this study is to document experience with patients 90 years of age or older in order to determine whether coronary artery bypass grafting surgery is justified. Eleven patients aged 90 years or more underwent cardiac surgery for symptomatic coronary artery disease refractory to medical management between January 1, 1987, and December 31, 1996. All patients were in NYHA Class IV preoper atively. In-hospital death occurred in two patients (18%). In-hospital morbidity occurred in all patients (100%) including seven cardiac, four respiratory, two neurologic, and one infectious. All survivors left the hospital symptomatically improved. The mean length of stay was 28 days. Four patients died at a mean of 2 years and 2 months post operatively. Five patients remain alive at a mean of 1 year and 7 months. Coronary artery bypass grafting in nonagenarians can be performed successfully in selected cases. However, increased mortality and morbidity rates and length of stay are associated with this age group. For survivors, the quality of life is improved and the projected life expectancy restored.

Argatroban as a Primary or Secondary Postoperative Anticoagulant in Patients Implanted With Ventricular Assist Devices

BACKGROUND We describe our experience with argatroban as a primary or secondary postoperative anticoagulant to heparin in patients receiving ventricular assist devices. METHODS This is a retrospective review of all Abiomed (BVS5000, AB5000) and Thoratec (PVAD and IVAD) ventricular assist devices from May 2003 through May 2006 at a single institution. Postoperatively, patients received either heparin or argatroban as their anticoagulant. Patients in whom heparin-induced thrombocytopenia was suspected or confirmed were converted from heparin to argatroban. RESULTS There were 33 Abiomed and Thoratec ventricular assist devices implanted. Thirteen patients received heparin as their primary postoperative anticoagulant; 8 of the 13 were converted to argatroban as a secondary anticoagulant (hep-arg), and 5 patients remained with heparin as their only anticoagulant. Twenty patients received argatroban as their primary and only postoperative anticoagulant. Thrombocytopenia occurred in 26 patients (79%) overall, 16 (80%) with argatroban only, 6 (75%) with hep-arg, and 4 (80%) with heparin only. Thromboembolic events occurred in 5 patients (15%) overall, 3 (15%) with argatroban only, 1 (13%) with hep-arg, and 1 (20%) with heparin only. Postoperative bleeding requiring reexploration occurred in 5 patients overall (15%), 1 with argatroban only (5%), 3 (38%) with hep-arg, and 1 (20%) with heparin only. Enzyme-linked immunosorbent assay heparin-induced thrombocytopenia tests were positive in 7 patients overall (21%), 5 (25%) with argatroban only, 2 (25%) with hep-arg, and 0 (0%) with heparin only. CONCLUSIONS Argatroban is a comparable primary or secondary anticoagulant to heparin postoperatively in patients receiving ventricular assist devices.

Superior Vena Cava Rupture during Balloon Angioplasty and Stent Placement to Relieve Superior Vena Cava Syndrome: A Case Report

Percutaneous stenting of the superior vena cava (SVC) has been an accepted therapy for SVC syndrome for more than a decade. Complications are uncommon and usually of minor consequence. Three previous reports have described ruptures of the SVC during venoplasty with death on one occasion. We report a fourth case of SVC rupture during angioplasty and stenting that required immediate pericardiocentesis followed by open surgical repair via sternotomy for direct control and repair. An algorithm for rapid recognition and prompt intervention is described.

Cardiac Ventricular Support: Considerations for Psychiatry

Cardiac ventricular support is fostering additional roles for psychiatric consultation with this vulnerable end-of-life cardiac group. Incidence of premorbid and postsurgical psychiatric disorders (Axis I), psychotropic use, neurologic events, and mortality was obtained for 21 Novacor left-ventricular assist system patients prospectively and 13 Abiomed left/right ventricular-assist device patients retrospectively. This fragile patient population and their families warrant involvement for psychiatry because of the extreme conditions and consequences associated with mechanical cardiac assistance. The authors address psychiatric morbidity and neurobehavioral modifications associated with ventricular support.