Successful lung transplantation in an HIV seropositive patient with desquamative interstitial pneumonia: a case report.

BACKGROUND: Until recently, lung transplantation was not considered in patients with human immunodeficiency virus (HIV). HIV seropositive patients with suppressed viral loads can now expect long-term survival with the advent of highly active antiretroviral therapies (HAART); however, HIV remains a relative contraindication to lung transplantation. We describe, to our knowledge, the first HIV seropositive lung transplant recipient in Canada. We also review the literature of previously reported cases of solid-organ transplantation in patients with HIV with a focus on immunosuppression considerations. CASE PRESENTATION: A 48-year old man received a bilateral lung transplant for a diagnosis of desquamative interstitial pneumonia (DIP) attributed to cigarette and cannabis smoking. His control of HIV infection pre-transplant was excellent on HAART, and he had no other contraindications to lung transplantation. The patient underwent bilateral lung transplantation using basiliximab, methylprednisolone, and mycophenolate mofetil (MMF) as induction immunosuppression. He was maintained on MMF, prednisone, and tacrolimus thereafter, and restarted his HAART regimen immediately post-operatively. His post-transplant course was complicated by Grade A1 minimal acute cellular rejection, as well as an enterovirus/rhinovirus graft infection. Despite these complications, his functional status and control of HIV infection remain excellent 24 months post-transplant. CONCLUSIONS: Our patient is one of only several HIV seropositive lung transplant recipients reported globally. With growing acceptance of transplantation in this population, there is a need for clarification of prognosis post-transplantation, as well as optimal immunosuppression regimens for these patients. This case report adds to the recent literature that suggests HIV seropositivity should not be considered a contraindication to lung transplantation, and that post-transplant patients with HIV can be managed safely with basiliximab, tacrolimus, MMF and prednisone.

Subsecond lung cancer detection within a heterogeneous background of normal and benign tissue using single-point Raman spectroscopy.

Significance: Lung cancer is the most frequently diagnosed cancer overall and the deadliest cancer in North America. Early diagnosis through current bronchoscopy techniques is limited by poor diagnostic yield and low specificity, especially for lesions located in peripheral pulmonary locations. Even with the emergence of robotic-assisted platforms, bronchoscopy diagnostic yields remain below 80%. Aim: The aim of this study was to determine whether in situ single-point fingerprint (800 to 1700 cm-1) Raman spectroscopy coupled with machine learning could detect lung cancer within an otherwise heterogenous background composed of normal tissue and tissue associated with benign conditions, including emphysema and bronchiolitis. Approach: A Raman spectroscopy probe was used to measure the spectral fingerprint of normal, benign, and cancer lung tissue in 10 patients. Each interrogated specimen was characterized by histology to determine cancer type, i.e., small cell carcinoma or non-small cell carcinoma (adenocarcinoma and squamous cell carcinoma). Biomolecular information was extracted from the fingerprint spectra to identify biomolecular features that can be used for cancer detection. Results: Supervised machine learning models were trained using leave-one-patient-out cross-validation, showing lung cancer could be detected with a sensitivity of 94% and a specificity of 80%. Conclusions: This proof of concept demonstrates fingerprint Raman spectroscopy is a promising tool for the detection of lung cancer during diagnostic procedures and can capture biomolecular changes associated with the presence of cancer among a complex heterogeneous background within less than 1 s.

Mechanisms of atrial tachyarrhythmias associated with coronary artery occlusion in a chronic canine model.

BACKGROUND: Coronary artery disease predisposes to atrial fibrillation (AF), but the effects of chronic atrial ischemia/infarction on AF-related substrates are unknown. METHODS AND RESULTS: Regional right atrial myocardial infarction (MI) was created in 40 dogs by ligating an artery that supplies the right atrial free wall and not the ventricles; 35 sham dogs with the same artery isolated but not ligated were controls. Dogs were observed 8 days after MI and subjected to open-chest study, in vitro optical mapping, and/or cell isolation for patch-clamp and Ca(2+) imaging on day 8. Holter ECGs showed more spontaneous atrial ectopy in MI dogs (eg, 662±281 on day 7 versus 34±25 ectopic complexes per day at baseline; 52±21 versus 1±1 atrial tachycardia episodes per day). Triggered activity was increased in MI border zone cells, which had faster decay of caffeine-evoked Ca(2+) transients and enhanced (by ≈73%) Na(+)-Ca(2+) exchange current. Spontaneous Ca(2+) sparks (confocal microscopy) occurred under ß-adrenergic stimulation in more MI dog cells (66±9%) than in control cells (29±4%; P<0.01). Burst pacing induced long-lasting AF in MI dogs (1146±259 versus 30±14 seconds in shams). Increased border zone conduction heterogeneity was confirmed by both bipolar electrode mapping in vivo and optical mapping. Optical mapping demonstrated stable border zone reentry in all 9 MI preparations but in none of 6 shams. Border zone tissue showed increased fibrous tissue content. CONCLUSIONS: Chronic atrial ischemia/infarction creates substrates for both spontaneous ectopy (Ca(2+)-release events, increased Na(+)-Ca(2+) exchange current) and sustained reentry (conduction abnormalities that anchor reentry). Thus, chronic atrial infarction in dogs promotes both AF triggers and the substrate for AF maintenance. These results provide novel insights into potential AF mechanisms in patients with coronary artery disease.

Enhanced Ca2+ entry due to Orai1 plasma membrane insertion increases IL-8 secretion by cystic fibrosis airways.

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR). The most common mutation, ΔF508, causes retention of CFTR in the endoplasmic reticulum (ER). Some CF abnormalities can be explained by altered Ca(2+) homeostasis, although it remains unknown how CFTR influences calcium signaling. This study examined the novel hypothesis that store-operated calcium entry (SOCE) through Orai1 is abnormal in CF. The significance of Orai1-mediated SOCE for increased interleukin-8 (IL-8) expression in CF was also investigated. CF and non-CF human airway epithelial cell line and primary cells (obtained at lung transplantation) were used in Ca(2+) imaging, electrophysiology, and fluorescence imaging experiments to explore differences in Orai1 function in CF vs. non-CF cells. Protein expression and localization was assessed by Western blots, cell surface biotinylation, ELISA, and image correlation spectroscopy (ICS). We show here that store-operated Ca(2+) entry (SOCE) is elevated in CF human airway epithelial cells (hAECs; ≈ 1.8- and ≈ 2.5-fold for total Ca(2+)(i) increase and Ca(2+) influx rate, respectively, and ≈ 2-fold increase in the I(CRAC) current) and is caused by increased exocytotic insertion (≈ 2-fold) of Orai1 channels into the plasma membrane, which is normalized by rescue of ΔF508-CFTR trafficking to the cell surface. Augmented SOCE in CF cells is a major factor leading to increased IL-8 secretion (≈ 2-fold). CFTR normally down-regulates the Orai1/stromal interaction molecule 1 (STIM1) complex, and loss of this inhibition due to the absence of CFTR at the plasma membrane helps to explain the potentiated inflammatory response in CF cells.

Vulnerable carotid atherosclerotic plaque creation in a Swine model: evaluation of stenosis creation using absorbable and permanent suture in a diabetic dyslipidemic model.

PURPOSE: To compare the creation of carotid atherosclerotic plaque after stenosis creation with absorbable or permanent suture in a diabetic dyslipidemic swine model. MATERIALS AND METHODS: A high-cholesterol diet was fed to 15 Sinclair pigs. Diabetes was induced by intraarterial injection of streptozotocin. Stenosis creation in carotid arteries was performed with an absorbable or a permanent suture assigned randomly on both sides. After 20 weeks, Doppler ultrasound (US), angiography, and intravascular US examinations were performed before sacrifice. Carotid, coronary, and femoral arteries were analyzed by histology according to the American Heart Association (AHA) classification. RESULTS: Three animals died during the perioperative period, and three others died during follow-up. Diabetes was successfully induced in all surviving animals (9 of 15). On angiography, stenoses were estimated at 80.4%±12.4 in carotid arteries with permanent sutures and at 48.8%±39 with absorbable sutures (P = .03). With permanent suturing, carotid plaques were observed in all animals with five of nine manifesting an AHA stage IV or more. With absorbable suture, atherosclerosis developed in seven of nine carotid arteries including three animals with an AHA stage IV or more. Advanced coronary and femoral plaques were observed in four and one of the nine animals. A correlation between AHA classes of coronary plaques and cholesterol level was observed (P = .01), whereas for carotid arteries, AHA class correlated with the degree of stenosis (P = .045). CONCLUSIONS: Creation of atheromatous lesions in carotid and coronary arteries was successful with this model despite a high mortality rate. Less severe carotid stenoses and advanced plaques were observed with absorbable sutures.

Lung Cryobiopsy Outside of the Operating Room: A Safe Alternative to Surgical Biopsy.

OBJECTIVE: Transbronchial lung cryobiopsy (TBLC) is a promising technique that can provide a histologic diagnosis in interstitial lung diseases (ILD) and is an alternative to surgical lung biopsy. The main concerns with the procedure are safety and diagnostic accuracy. The technique is applicable in patients unable to undergo surgical biopsy due to severe comorbidities or when patient transport to the operating room is dangerous. This study reports the initial experience with TBLC on a thoracic surgical service as a first attempt at diagnosis in patients with diffuse parenchymal lung diseases (DPLD). METHODS: Between May 2018 and July 2020, 32 patients underwent TBLC using bedside flexible bronchoscopy for suspected ILD on a thoracic surgical endoscopy service. Retrospective evaluation of the procedure details, complications, and diagnostic yield were analyzed and reported. RESULTS: A total of 89 pathological samples were obtained (mean 2.8 per patient). Pneumothorax and minor bleeding occurred in 25% and 16.7% of patients, respectively. Sixty-seven percent of complications occurred with use of the 2.4 mm cryoprobe (P = 0.036). Concordance between the histologic diagnosis and final clinical diagnosis was observed in 62.5% of patients and the pathology guided the final treatment in 71% (P = 0.027) with Kappa-concordance of 0.60 (P < 0.001). CONCLUSIONS: Cryobiopsy is becoming part of the diagnostic evaluation in patients with indeterminate DPLD or hypoxemic respiratory failure. TBLC is easy to perform and has a favorable safety profile. Thoracic specialists should consider adding TBLC to their procedural armamentarium as a first option for patients with indeterminate PLD.

Heart rate reduction by ivabradine reduces diastolic dysfunction and cardiac fibrosis.

OBJECTIVES: To determine if heart rate (HR) reduction with ivabradine (IVA), a selective inhibitor of the pacemaker I(f) current, prevents cardiac dysfunction associated with dyslipidemia. METHODS: New Zealand White rabbits received either a standard diet, a 0.5% cholesterol-enriched diet only (CD), or a 0.5% CD with IVA (17 mg/kg/day) for 12 weeks. HR, left ventricular (LV) systolic function, diastolic function and LV regional myocardial performance index (MPI) were studied using echocardiography. Histological analysis included cardiac interstitial fibrosis and collagen type I fibers. Plasma levels of angiotensin II and aldosterone were quantified by immunoassays. RESULTS: IVA reduced HR by approximately 11%. IVA improved MPI and attenuated LV diastolic dysfunction (DD) (92% mild and 8% moderate DD with IVA vs. 54% mild and 46% moderate DD in CD group). IVA also reduced atrial fibrosis (p = 0.027), ventricular fibrosis (p = 0.0002) and ventricular collagen type I (p = 0.0042). IVA decreased plasma angiotensin II levels (p = 0.042), and both angiotensin II and aldosterone levels were correlated with HR (p = 0.038 and 0.008). CONCLUSION: Selective HR reduction with IVA reduces DD and cardiac fibrosis in hypercholesterolemic rabbits. These beneficial effects of IVA support testing pure HR reduction in patients with diastolic heart failure.

Comparative performance of four malaria rapid diagnostic tests, Vikia Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf, among febrile patients in Gabon.

INTRODUCTION: Rapid diagnostic tests (RDTs) are selected based on their performances. Here, we compared the diagnostic performance of different malaria RDTs. METHODS: Febrile patients were tested for malaria using Vikia Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf RDTs at Melen Regional Hospital in Gabon. RESULTS: In total, 120 of 274 tested children (43.8%) had malaria. The sensitivity was > 95% for all RDTs, while the specificity was > 85% for two tests. One test generated invalid tests (8%). CONCLUSIONS: Based on their performances, all tests except one may be recommended for malaria diagnosis.

Transcatheter Aortic Valve Replacement in a Patient With a Previous Bioprosthetic Mitral Valve Replacement: Report of a Delayed Fatal Interaction.

We report on a man with bioprosthetic mitral valve perforation who presented late after transcatheter aortic valve replacement with a balloon-expandable transcatheter heart valve (THV). The protrusion of the commissural strut of the bioprosthetic mitral valve coupled with the low implanted THV resulted in repetitive trauma leading to rupture of a mitral leaflet. Potential preventive strategies are discussed. This case illustrates the importance of preprocedural imaging screening and cautious THV deployment in patients with a bioprosthetic mitral valve.

Resection of a right atrial epithelioid hemangioendothelioma.

A right atrial mass excised from the heart of a 53-year-old man was incidentally found to be an epithelioid hemangioendothelioma (EHE). EHE is a rare malignant tumor with marked variability in clinical outcomes. Cardiac involvement is unusual but does occur [Bisesi MA, Broderick LS, Smith JA. MR demonstration of right atrial involvement in multifocal epithelioid hemangioendothelioma. AJR Am J Roentgenol 1996;167(4):953-4; Di Biasi P, Scrofani R, Santoli C. Cardiac hemangioendothelioma. Ann Thorac Surg 1995;59(3):792-3], and the prognostic is usually considered relatively good after resection. However, the tumor in this case shows atypical features, which raises concerns. In addition to complete en bloc resection, a close follow-up is considered mandatory.

Left Atrial Inexcitability in Children With Congenital Lupus-Induced Complete Atrioventricular Block.

BACKGROUND: Congenital atrioventricular block is a well-established immunologic complication of maternal systemic lupus erythematosus. We sought to further characterize the electrophysiological manifestations of maternal systemic lupus erythematosus on neonatal atria. METHODS AND RESULTS: Cases of isolated congenital atrioventricular block treated at our center over the past 41 years were identified. Data were extracted from clinical charts, pacemaker interrogations, ECGs, echocardiograms, and histopathological reports, when available. Of 31 patients with isolated congenital atrioventricular block, 18 were negative for maternal antibodies and had normal epicardial atrial sensing and pacing thresholds. In contrast, 12 of 13 patients with positive maternal antibodies had epicardial pacemakers, 5 (42%) of whom had left atrial (LA) inexcitability and/or atrial conduction delay. In 3 patients, the LA could not be captured despite high-output pacing. The fourth patient had acutely successful LA appendage and left ventricular lead placement. At early follow-up, an increased delay between the surface P-wave and intracardiac atrial depolarization was observed, indicative of atrial conduction delay. The fifth patient exhibited LA lead dysfunction, with atrial under-sensing and an increased capture threshold, 2 weeks after implantation. Biopsies of LA appendages performed in 2 patients showed no evidence of atrial fibrosis or loss of atrial myocytes. CONCLUSIONS: Herein, we report previously undescribed yet prevalent electrophysiological ramifications of maternal systemic lupus erythematosus, which extend beyond congenital atrioventricular block to encompass alterations in LA conduction, including LA inexcitability. These manifestations can complicate epicardial pacemaker implantation in newborns. In the absence of histological evidence of extensive atrial fibrosis, immune-mediated functional impairment of electrical activity is suspected.

Comparative performance of four malaria rapid diagnostic tests, Vikia Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf, among febrile patients in Gabon

Abstract INTRODUCTION: Rapid diagnostic tests (RDTs) are selected based on their performances. Here, we compared the diagnostic performance of different malaria RDTs. METHODS: Febrile patients were tested for malaria using Vikia Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf RDTs at Melen Regional Hospital in Gabon. RESULTS: In total, 120 of 274 tested children (43.8%) had malaria. The sensitivity was > 95% for all RDTs, while the specificity was > 85% for two tests. One test generated invalid tests (8%). CONCLUSIONS: Based on their performances, all tests except one may be recommended for malaria diagnosis.

An unusual case of giant cell myocarditis missed in a Heartmate-2 left ventricle apical-wedge section: a case report and review of the literature.

Herein we present a case of fulminant myocarditis in a woman previously treated for B-cell lymphoma. While the clinical context was suggestive of adriamycin-induced cardiomyopathy, the initial pathology of the Heartmate-2 apical core showed lymphocytic myocarditis. After 8 months of stability, the patient presented with progressive heart failure and recurrent ventricular arrhythmias. An endomyocardial biopsy revealed findings typical of giant cell myocarditis (GCM); poor response to immunosuppressive therapy and marked hemodynamic instability led to urgent transplantation. To our knowledge, this is the first reported case of GCM following an acute lymphocytic myocarditis and the second GCM case associated with B-cell lymphoma.

Extensive radiation-induced heart disease in an adult patient treated for lymphoma as a child.

Cardiovascular complications are the second leading cause of late mortality in survivors of Hodgkin's lymphoma (HL) exposed to mediastinal radiotherapy. Symptomatic cardiac disease following classic thoracic irradiation for HL is reported in 10%-30% of patients at 5-10 years of follow-up. We present the case of a 44-year-old man with a history of left cervical nodular lymphocyte predominant HL treated at childhood with 40 Gy extended field thoracic irradiation (Mantle) who presented with mixed aortic and mitral valve disease, coronary artery stenosis, myocardial and aortic calcifications, and mediastinal fibrosis. Despite extensive cardiac surgery, the postoperative course was complicated and resulted in the patient's death. We review herein the typical cardiac involvement related to mediastinal radiotherapy and the controversies surrounding its surgical approach.

Diaphragmatic electromyography during cryoballoon ablation: a novel concept in the prevention of phrenic nerve palsy.

BACKGROUND: Hemidiaphragmatic paralysis is the most frequent complication associated with cryoballoon ablation for atrial fibrillation. To date, no preventive strategy has proved effective. OBJECTIVE: We sought to assess the feasibility of diaphragmatic electromyography during cryoballoon ablation, explore the relationship between altered signals and phrenic nerve palsy, and define characteristic changes that herald hemidiaphragmatic paralysis. METHODS: Cryoballoon ablation was performed in the right superior pulmonary vein or superior vena cava in 16 mongrel dogs weighing 37.7 ± 2.4 kg, at sites determined by phrenic nerve capture. During ablation, the phrenic nerve was paced at 60 bpm from the superior vena cava while recording diaphragmatic compound motor action potentials (CMAPs) by esophageal decapolar catheters. Diaphragmatic excursion was monitored by fluoroscopy and abdominal palpation. RESULTS: Before ablation, the CMAP amplitude was 592 (interquartile range 504, 566) µV, initial latency 21.5 ± 4.2 ms, peak latency 64.7 ± 21.1 ms, and duration 101.7 ± 13.3 ms. Hemidiaphragmatic paralysis was obtained in all dogs 62 ± 34 seconds into the cryoapplication. The CMAP amplitude decreased exponentially, with no patterned changes in latencies and duration. Discriminatory analyses by receiver-operating curve characteristics identified a 30% reduction in CMAP amplitude as the most predictive cutoff value for hemidiaphragmatic paralysis (c-statistic 0.965; P<.0001). This criterion presaged diaphragmatic paralysis, as detected by abdominal palpation, by 31 ± 23 seconds. CONCLUSION: Diaphragmatic electromyographic signals could be reliably recorded during cryoballoon ablation. An exponential decrease in CMAP amplitude precedes diaphragmatic paralysis, with a 30% reduction yielding the best discriminatory potential. A promising safety margin was detected, which merits prospective validation.

Sudden death after intravenous administration of a perflutren contrast agent: a case of pseudocomplication?

Perflutren cardiac ultrasound agents improve diagnostic accuracy in patients whose imaging is technically difficult. This report describes a case of sudden death approximately 5 minutes after the intravenous administration of 0.5 mL of perflutren contrast agent (Definity) during transthoracic echocardiography with suboptimal baseline images performed 10 days after coronary artery bypass graft surgery because of hypotension and tachycardia in a 73-year-old patient with severe left ventricular systolic dysfunction. Autopsy did not reveal a clear direct relationship between perflutren and death. This is the first reported case of death related temporally to an echocardiographic contrast agent occurring in Canada and could represent a case of pseudocomplication.