P. Spratt

Selective Inhibition Of Nitric Oxide Production During Cardiac Allograft Rejection Causes A Small Increase In Graft Survival

Nitric oxide production is increased in allograft rejection and may have both beneficial and deleterious effects on graft function and survival. In animal models, conventional immunosuppressive agents have been shown to decrease nitric oxide production. The aim of our study was to determine what effect augmentation and selective inhibition of nitric oxide production may have on graft survival by using the model of heterotopic cardiac transplantation in the rat. L-Arginine, the naturally occurring substrate for nitric oxide production, was administered subcutaneously at 200 mg/kg/day. L-NG-monomethyl-L-arginine (L-NMMA) is a selective inhibitor of nitric oxide synthase and was administered at 500 mg/kg/day to allograft recipients from the day of operation. Endogenous nitric oxide production was quantified by analysis of urinary nitrate excretion, and time to rejection was determined by graft palpation. L-Arginine did not significantly alter urinary nitrate excretion by iso- or allografts, suggesting that nitric oxide production is not a substrate-limited process in this model. Graft survival in this group was unchanged. L-NMMA produced a small increase in graft survival from 5.1 +/- 0.1 to 6.3 +/- 0.3 days compared with control allografts (P = 0.001) and abolished the rise in urinary nitrate excretion seen with control allografts. Lower doses of L-NMMA produced dose-related decrements in urinary nitrate excretion, but did not alter graft survival. We found that allograft rejection can proceed to graft loss despite complete inhibition of the increase in nitric oxide production that occurs during untreated rejection. The small increase in graft survival suggests that nitric oxide plays a minor role as a cytotoxic effector molecule in this model of acute rejection.

Left Ventricular Mechanical Assist Devices and Cardiac Device Interactions: An Observational Case Series

Background: Nonpulsatile left ventricular assist devices (LVADs) are increasingly used for treatment of refractory heart failure. A majority of such patients have implanted cardiac devices, namely implantable cardioverter‐defibrillators (ICDs) or cardiac resynchronization therapy‐pacemaker (CRT‐P) or cardiac resynchronization therapy‐defibrillator (CRT‐D) devices. However, potential interactions between LVADs and cardiac devices in this category of patients remain unknown.

Impact of Implantable Cardioverter Defibrillators on Survival of Patients with Centrifugal Left Ventricular Assist Devices

Both implantable cardioverter defibrillators (ICDs) and left ventricular assist devices (LVADs) have a positive impact on survival in the heart failure population. We sought to determine whether these positive effects on survival are additive or whether LVAD therapy supersedes ICD therapy.

Pulmonary vein thrombosis treated successfully by thrombectomy after bilateral sequential lung transplantation: report of a case.

Abstract.We report the case of a 35-year-old man in whom an acute pulmonary vein thrombosis developed following bilateral sequential lung transplantation for cystic fibrosis. The thrombus was detected by transesophageal echocardiography 12 h after transplantation and an emergency thrombectomy was successfully performed.

PAPAVERIVE ABOLISHES ENDOTHELIUM-DEPENDENT DILATATION OF HUMAN INTERNAL MAMMARY ARTERIES IN VITRO

1. The purpose of the present study was to examine the effects of papaverine‐HCl, administered into the lumen of the human internal mammary artery (IMA) during harvesting of this vessel, on vascular reactivity in vitro and to specifically test the hypothesis that intraluminal administration of papaverine‐HCl impairs endothelium‐dependent vasodilation.

Optimization of left ventricular function with carvedilol before high-risk cardiac surgery.

Patients with severe left ventricular dysfunction and symptomatic heart failure caused by ischemic or valvular heart disease face a high morbidity and mortality risk from cardiac surgery. We present data showing that excellent surgical outcome can be achieved after pre-treatment of such patients with carvedilol.

Interventional bronchoscopy for the management of airway complications following lung transplantation

STUDY OBJECTIVES To assess the efficacy and complications of different interventional bronchoscopic techniques used to treat airway complications after lung transplantation. DESIGN Retrospective study. SETTING Heart-lung transplant unit of a university hospital. PATIENTS From November 1986 to January 2000, interventional bronchoscopy was performed in 41 of 312 lung transplant recipients (13.1%) for tracheobronchial stenosis, bronchomalacia, granuloma formation, and dehiscence. INTERVENTIONS Dilatation, stent placement, laser or forceps excision. MEASUREMENTS AND RESULTS Mean (+/- SE) improvement in FEV(1) in 26 patients undergoing dilatation for a stenotic or a combined lesion was 93 +/- 334 mL or 8 +/- 21%. In seven of these patients not proceeding to stent placement, mean improvement in FEV(1) was 361 +/- 179 mL or 21 +/- 9%. Patients needing stent placement after dilatation had a mean change in FEV(1) after dilatation of - 5 +/- 325 mL or 3 +/- 23%, and an improvement of 625 +/- 480 mL or 52 +/- 43% after stent insertion. Mean improvement in FEV(1) for patients treated with stent insertion for bronchomalacia was 673 +/- 30 mL or 81 +/- 24%. Complications of airway stents were migration (27%), mucous plugging (27%), granuloma formation (36%), stent fracture (3%), and formation of a false passage (6%). Mortality associated with interventional bronchoscopy was 2.4% (1 of 41 patients). For patients with airway complications successfully undergoing interventional bronchoscopy, the overall 1-year, 3-year, and 5-year survival rates were 79%, 45%, and 32%, respectively, vs 87%, 69%, and 56% for those without airway complications (p < 0.05). CONCLUSION Only a small number of patients with airway stenosis after lung transplantation will respond to bronchial dilatation alone. Patients with airway complications after lung transplantation have a higher mortality than patients without airway complications.

Primary percutaneous coronary intervention for inferior ST‐segment elevation myocardial infarction in a patient supported by the HeartWare left ventricular assist device

A 63‐year‐old man with an ischaemic cardiomyopathy, supported by the HeartWare left ventricular assist device (LVAD), presented with ventricular tachycardia and inferior ST‐elevation myocardial infarction (STEMI) with associated acute right ventricular (RV) dysfunction. He underwent primary percutaneous coronary intervention with balloon angioplasty and placement of three drug‐eluting stents in the proximal‐to‐mid right coronary artery. Post‐procedure, ventricular arrhythmias abated, RV systolic dysfunction resolved and RV size normalised. Percutaneous coronary intervention (PCI) facilitated by the use of miniaturised percutaneous LVAD has become an increasingly available treatment option for high‐risk patients. PCI in patients on established full mechanical circulatory support is not a common occurrence. Indeed, to our knowledge, this is the first case of primary percutaneous coronary intervention on an LVAD‐supported heart reported in the medical literature. The case raises several specific issues that are of peculiar interest to clinicians involved in the care of patients supported by mechanical assist devices who experience an acute coronary syndrome requiring emergent revascularisation.