Extracorporeal life support to left ventricular assist device bridge to heart transplant: A strategy to optimize survival and resource utilization

BACKGROUND

The use of extracorporeal life support (extracorporeal membrane oxygenation [ECMO]) as a direct bridge to heart transplant in adult patients is associated with poor survival. Similarly, the use of an implantable left ventricular assist device (LVAD) to salvage patients with cardiac arrest, severe hemodynamic instability, and multiorgan failure results in poor outcome. The use of LVAD implant in patients who present with cardiogenic shock who have not been evaluated for transplantation or who have sustained a recent myocardial infarction also raises concerns. ECMO may provide reasonable short-term support to patients with severe hemodynamic instability, permit recovery of multiorgan injury, and allow time to complete a transplant evaluation before long-term circulatory support with an implantable LVAD is instituted. After acquisition of the HeartMate LVAD (Thermo Cardiosystems, Inc), we began using ECMO as a bridge to an implantable LVAD and, subsequently, to transplantation in selected high-risk patients.

METHODS AND RESULTS

From October 1, 1996, through September 30, 1998, 32 adult patients who presented with refractory cardiogenic shock (cardiac index <2.0 L. min(-1). m(-2), with systolic blood pressure <100 mm Hg and pulmonary capillary wedge pressure >/=24 mm Hg and dependent on >/=2 inotropes with or without intra-aortic balloon pump) were evaluated and accepted as candidates for mechanical assistance as a bridge to transplant. Of the 32 patients, 14 (group I) had a cardiac arrest or severe hemodynamic instability (systolic blood pressure </=75 mm Hg) with evidence of multiorgan failure (defined as serum creatinine level >3 mg/dL or oliguria; international normalized ratio >1.5 or transaminases >5 times normal or total bilirubin >3 mg/dL; and needing mechanical ventilation). Group I patients were placed on ECMO support; 7 underwent subsequent LVAD implant and 1 was bridged directly to transplant. Six patients in group I survived to transplant hospitalization discharge. The remaining 18 patients (group II) underwent LVAD implant without ECMO support; 12 survived to transplant hospitalization discharge and 2 remained alive with ongoing LVAD support and awaited transplant. One-year actuarial survival from the initiation of circulatory support was 43% in group I and 75% in group II. One-year actuarial survival from the time of LVAD implant in group I, conditional on surviving ECMO, was 71% (P=NS compared with group II).

CONCLUSIONS

In appropriately selected high-risk patients, the rate of LVAD survival after initial ECMO support was not significantly different from the survival rate after LVAD support alone. An initial period of resuscitation with ECMO is an effective strategy to salvage patients with extreme hemodynamic instability and multiorgan injury. Use of LVAD resources is improved by avoiding LVAD implant in a very-high-risk cohort of patients who do not survive ECMO.

[Compulsive disorder with homicidal impulses and paranoid symptoms in vascular encephalopathy]

We report on the case of a 45-year old man with OCD who had the obsessive impulse to kill his 3-year old son. The patient showed signs of vascular encephalopathy after perinatal brain damage; besides that, he had developed a mild "explanatory" delusional system. Under treatment with SSRI and clozapin he improved remarkably. Presenting this case, we discuss the connection between organic disorders and OCD, and especially its relationship to perinatal brain damage.

Relationship of amiodarone to postoperative complications of transthoracic implantation of automatic implantable cardioverter defibrillators

The purpose of this study is to report the results and complications associated with transthoracic placement of an implantable defibrillator and their relationship to amiodarone, and to identify clinical predictors of complications. There were 159 men and 41 women. The mean patients age was 61 +/- 11 years, and the mean ejection fraction was 0.33 +/- 0.14. Fifty one percent of patients developed complications including death in 14 patients (7%). Variables which differed in patients who died and those that did not were age, ejection fraction and New York heart failure classifications. Postoperative mortality was unrelated to amiodarone therapy. Twenty patients (10%) developed pneumonia and 15 patients (7.5%) developed respiratory failure. Clinical variables associated with the development of respiratory failure were age, amiodarone therapy and a prior history of pulmonary disease. Patients receiving amiodarone had a higher incidence of an elevated defibrillation threshold (> or = 25 joules) as compared with those not being treated with amiodarone. Clinical factors associated with an elevated defibrillation threshold were a history of a myocardial infarction, prior bypass surgery, and amiodarone. The results of this study demonstrate that placement of an implantable defibrillator using a transthoracic approach is associated with a high incidence of complications. Amiodarone therapy is associated with an increased incidence of pneumonia, respiratory failure, and elevated defibrillation thresholds.

Bypass Angioplasty Revascularization Investigation: patient screening, selection, and recruitment

Percutaneous transluminal coronary angioplasty (PTCA) is currently performed in many patients seeking care because of severe manifestations of multivessel coronary artery disease. Previously, the majority of such patients would have undergone coronary artery bypass grafting (CABG). No definitive evidence is available as to which initial revascularization strategy has the best long-term clinical and economic outcomes. The Bypass Angioplasty Revascularization Investigation (BARI) is the largest of several recent clinical trials that were designed to test the hypothesis that an initial strategy of PTCA in selected patients with multivessel coronary artery disease does not compromise long-term clinical outcome compared with an initial strategy of CABG. This report describes how patients were screened, selected, and recruited in BARI and how this process may influence the results and the interpretation of the trial. During the enrollment period, 25,200 patients undergoing diagnostic coronary angiography at the participating institutions or with off-site angiograms referred to BARI investigators were screened for BARI eligibility. Excluded from screening were patients without coronary artery disease, those with single-vessel disease, prior revascularization, primary congenital, valvular, or myocardial disease, and age > 80 years. Slightly more than half of the patients screened (12,670) were not clinically eligible for BARI because of left main disease, insufficient symptoms, emergency revascularization, or other logistic reasons. Thus, 12,530 patients had severe angina and/or ischemia and were clinically eligible for BARI. Nearly 33% of them (4,110) had multivessel disease, which was suitable for both PTCA and CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation between scintigraphic evidence of regional sympathetic neuronal dysfunction and ventricular refractoriness in the human heart

BACKGROUND

Denervation supersensitivity has been proposed as a mechanism for the relation between ventricular arrhythmias and the sympathetic nervous system. Evaluation of this phenomenon in humans has become feasible only recently with the development of noninvasive scintigraphic methods for evaluating the pattern of sympathetic innervation. The purpose of this study was to determine if scintigraphic evidence of sympathetic neuronal dysfunction correlates with measurements of ventricular refractoriness and to evaluate the phenomenon of denervation supersensitivity in humans.

METHODS AND RESULTS

Eleven patients with a history of sustained ventricular tachycardia or sudden cardiac death who were referred for placement of an implantable defibrillator participated in this study (seven men and four women; age, 51 +/- 18 years). Preoperative scintigraphic evaluation of the pattern of sympathetic innervation was performed with 11C-hydroxyephedrine in conjunction with positron emission tomography. At the time of surgery, ventricular refractoriness was determined in regions of myocardium demonstrating normal and reduced 11C-hydroxyephedrine retention in the baseline state and during an infusion of norepinephrine. Scintigraphic evaluation demonstrated regions of reduced 11C-hydroxyephedrine retention in each patient. The effective refractory period in areas of myocardium that demonstrated reduced 11C-hydroxyephedrine retention was significantly longer than in areas of myocardium demonstrating normal 11C-hydroxyephedrine retention (273 +/- 32 versus 243 +/- 32 msec, p < 0.001). Norepinephrine shortened the effective refractory period in regions of myocardium demonstrating normal and reduced 11C-hydroxyephedrine retention to a similar degree.

CONCLUSIONS

There is a correlation between scintigraphic evidence of sympathetic neuronal dysfunction and ventricular refractoriness in the human heart. These observations help validate the use of scintigraphic techniques for evaluation of sympathetic innervation and may assist in the further evaluation of the relation between the sympathetic nervous system and ventricular arrhythmias.

Expression of recombinant genes in myocardium in vivo after direct injection of DNA

The ability to program recombinant gene expression in cardiac myocytes in vivo holds promise for the treatment of many inherited and acquired cardiovascular diseases. In this report, we demonstrate that a recombinant beta-galactosidase gene under the control of the Rous sarcoma virus promoter can be introduced into and expressed in adult rat cardiac myocytes in vivo by the injection of purified plasmid DNA directly into the left ventricular wall. Cardiac myocytes expressing recombinant beta-galactosidase were detected histochemically in rat hearts for at least 4 weeks after injection of the beta-galactosidase gene. These results demonstrate the potential of this method of somatic gene therapy for the treatment of cardiovascular disease.