Saira Farid

Role of 18F-FDG PET/CT in the diagnosis of cardiovascular implantable electronic device infections: A meta-analysis

ObjectiveWe performed a meta-analysis evaluating the use of fluorine-18-fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET)/computed tomography (CT) in the diagnosis of cardiovascular implantable electronic device (CIED) infections.BackgroundPET/CT may be helpful in the diagnosis of CIED infection, particularly in patients with the absence of localizing signs or definitive echocardiographic findings.MethodsPubMed, Embase, Cochrane library, CINAHL, Web of Knowledge, and www.clinicaltrials.gov from January 1990 to April 2017 were searched for studies evaluating the accuracy of PET/CT in the diagnosis of CIED infections.ResultsOverall, 14 studies involving 492 patients were included in the meta-analysis. The pooled sensitivity of PET/CT for diagnosis of CIED infection was 83% (95% CI 78%-86%) and the pooled specificity was 89% (95% CI 84%-94%). PET/CT demonstrated a higher sensitivity of 96% (95% CI 86%-99%) and specificity of 97% (95% CI 86%-99%) for diagnosis of pocket infections. Diagnostic accuracy for lead infections or CIED-IE was lower with pooled sensitivity of 76% (95% CI 65%-85%) and specificity of 83% (95% CI 72%-90%).ConclusionUse of PET/CT in the evaluation of CIED infection has both a high sensitivity (83%) and specificity (89%) and deserves consideration in the management of selected patients with suspected CIED infections.

Helcococcus kunzii prosthetic valve endocarditis secondary to lower extremity cellulitis

An 88-year-old man with history of bioprosthetic aortic valve replacement was hospitalised with fever, chills, malaise and right lower extremity cellulitis. Laboratory investigations revealed leucocytosis and blood cultures grew Helcococcus kunzii. Although transoesophageal echocardiography was negative for endocarditis, the patient was treated with 4 week of intravenous ceftriaxone. However, he was readmitted 6 weeks later with symptoms of fever, chills and hypoxia in setting of recurrent H. kunzii bacteraemia. A repeat transoesophageal echocardiogram revealed a mobile mass on bioprosthetic aortic valve, severe perivalvular insufficiency with pseudoaneurysm formation, and severe native mitral and tricuspid valve regurgitation. Cardiothoracic surgery was consulted and the patient underwent replacement of aortic valve and aortic root, and tricuspid and mitral valve repairs. Histological examination of excised bioprosthetic aortic valve revealed active endocarditis with cocci identified on silver stain. Patient was successfully treated with 4-week course of intravenous ceftriaxone and was doing well at 2-year follow-up.

Isolated cerebral mucormycosis caused by Rhizomucor pusillus

A 61-year-old man with relapsing chronic lymphocytic leukaemia, status post allogeneic stem cell transplant and multiple chemotherapy regimens presented to the emergency room after suffering a grand mal seizure. His evaluation revealed a 1.5–2 cm ring-enhancing left temporal lobe brain lesion on the CT scan. This brain lesion was resected and the histopathology revealed an invasive fungal organism resembling mucormycosis. Amplification and sequencing of the 28S ribosomal RNA gene identified the organism as Rhizomucor pusillus. The patient was treated with liposomal amphotericin B 5 mg/kg every 24 hours for 4 weeks, and then was transitioned to oral posaconazole. Serial brain imaging at 1 and 3 months, while on therapy, showed significant improvement.

Unrecognized pre-transplant disseminated Coxiella burnetti infection diagnosed in a post-transplant heart-kidney recipient

To the best of our knowledge, we report the first case of pre‐transplant unrecognized disseminated Coxiella burnetii infection, unmasked in the post‐transplant period leading to both heart and kidney allograft dysfunction. A 59 year old man with a history of simultaneous heart‐kidney transplantation due to end stage heart failure from severe aortic regurgitation (AR) and cryoglobulinemic immune complex mediated concentric necrotizing glomerulonephritis (GN), presents with a history of intermittent fevers and fatigue. Prior to transplantation he was treated for multiple episodes of culture negative endocarditis requiring bio‐prosthetic valve replacement. Evaluation of fever included a transesophageal echocardiogram (TEE) that revealed a large hyperechoic mass on the anterior mitral leaflet with perforation, severe mitral regurgitation and moderate AR. Blood cultures were negative at that time. Owing to development of allograft mitral and aortic valve insufficiency, he underwent allograft bio‐prosthetic mitral valve (MV) replacement and aortic valvuloplasty 2 years following his transplantation. Pathologic examination of the allograft mitral valve demonstrated fibrinopurulent exudate with degenerating bacterial organisms, consistent with vegetation and myxoid degenerative changes. Due to a high suspicion for native heart C. burnetii prosthetic valve endocarditis prior to transplantation, we re‐evaluated the native explanted heart histopathology, as well as the explanted allograft MV. Cardiac allograft and native MV were positive for C. burnetii by real‐time PCR. C. burnetii serology was consistent with persistent infection as well.

Diagnostic evaluation and management of culture-negative cardiovascular implantable electronic device infections

Culture‐negative (CN) cardiovascular implantable electronic device (CIED) infections represent a significant management challenge for clinicians with no specific guidelines addressing this subgroup of patients. The aim of the current investigation is to report our institutional experience of CN CIED infections and propose a systematic approach to diagnostic evaluation and management of these complicated cases based on our observations.

Clinical Manifestations and Outcomes of Fluoroquinolone-Related Acute Interstitial Nephritis

Objective: To describe the clinical presentation, diagnosis, and outcomes of patients with biopsy‐proven acute interstitial nephritis (AIN) related to fluoroquinolone (FQ) therapy. Patient and Methods: We conducted a retrospective review of biopsy‐proven AIN attributed to FQ use at Mayo Clinics campus in Rochester, Minnesota, from January 1, 1993, through December 31, 2016. Cases were reviewed by a renal pathologist and attributed to FQ use by an expert nephrologist. We also reviewed and summarized all published case reports of biopsy‐proven AIN that were attributed to FQ use. Results: We identified 24 patients with FQ‐related biopsy‐proven AIN at our institution. The most commonly prescribed FQ was ciprofloxacin in 17 patients (71%), and the median antibiotic treatment duration was 7 days (interquartile range [IQR], 5‐12 days). The median time from the initiation of FQ to the diagnosis of AIN was 8.5 days (IQR, 3.75‐20.75 days). Common clinical manifestations included fever (12; 50%), skin rash (5; 21%), and flank pain (2; 8%), and 9 (38%) had peripheral eosinophilia. However, 4 (17%) of the patients were asymptomatic at the time of diagnosis and AIN was suspected on the basis of routine laboratory monitoring. Most patients (17; 71%) recovered after the discontinuation of antibiotic therapy, and renal function returned to baseline at a median of 20.5 days (IQR, 11.75‐27.25 days). Six patients (25%) required temporary hemodialysis, and 14 patients (58%) received corticosteroid therapy. Conclusion: The onset of FQ‐related AIN can be delayed, and a high index of suspicion is needed by physicians evaluating these patients. Overall outcomes are favorable, with recovery to baseline renal function within 3 weeks of discontinuing the offending drug.

Strategies to Prevent Infections Associated with Cardiovascular Implantable Electronic Devices.

ABSTRACT Introduction: Infections involving cardiovascular implantable electronic devices (CIED) are associated with high morbidity and mortality and substantial financial cost. In the past two decades, the rate of CIED infections has increased disproportionate to the number of devices implanted, likely due to aging patient population with multiple comorbidities. Microbial contamination of the generator pocket and or leads by skin flora at the time of implantation is a major mechanism for early CIED infections. Due to resistance to host immune cells and antibiotics caused by biofilm formation, complete removal of the device generator and leads is required to achieve cure. Areas covered: In this manuscript, we review the published literature regarding epidemiology, risk factors, and pathogenesis of CIED infections with primary focus on the preventative strategies to reduce the incidence of device infections. Expert commentary: Strict adherence to infection control measures at the time of CIED implantation is critical in reducing the risk of device infection while adjunctive strategies such as use of antimicrobial envelopes might help in certain high-risk individuals. Technological advances in device manufacturing with availability of subcutaneous devices without transvenous leads and self-contained intracardiac devices without leads and generator show promise with lower risk of infection.

Postsurgical mediastinal aspergilloma masquerading as malignancy

A 70-year-old man with non-ischaemic dilated cardiomyopathy presented with symptoms of fatigue, chills and unintentional weight loss over the past 2 months. Initial evaluation revealed anaemia, peripheral leucocytosis and elevated inflammatory markers. Results of an oesophagogastroduodenoscopy, colonoscopy, blood bacterial and fungal cultures and bone marrow biopsy were negative. An 18F-FDG positron-emission tomography-CT demonstrated an indeterminate, intensely FDG-avid 5 cm × 2 cm × 5.6 cm × 6.7 cm mass centred within the junction of the superior vena cava and right atrium, suggestive of probable malignancy versus an inflammatory thrombus. After multidisciplinary consideration, patient underwent a diagnostic minithoracotomy and a thick fibrotic mediastinal mass was visualised and evacuated. The encapsulated mass contained thick, white creamy liquid that appeared to be purulent/necrotic material. The biopsies of the capsule wall on frozen section demonstrated fungal elements consistent with Aspergillosis species. Fungal culture confirmed diagnosis of Aspergillus fumigatus.