Anubhav Kanwar

Cardiac magnetic resonance evaluation of left ventricular remodelling distribution in cardiac amyloidosis

Background Cardiac amyloidosis (CA) is associated with typical morphological features on echocardiography, including concentric LV hypertrophy (LVH). Cardiac magnetic resonance (CMR) can accurately depict anatomy in different cardiomyopathies. Our aim was to describe the morphological features and remodelling patterns of CA with CMR, and establish their diagnostic accuracy, as well as the value of traditional diagnostic criteria derived from echocardiography and electrocardiography. Methods Consecutive patients referred for CMR for possible CA were retrospectively evaluated. The diagnosis of CA was established in the presence of a positive cardiac biopsy and/or a typical pattern of myocardial late gadolinium enhancement. Morphological parameters were obtained from standard cine sequences. The presence and distribution of LVH, relative wall thickness (RWT) and LV remodelling patterns were determined. Results 130 patients (92 males (70.8%), age 64±13 years) were included. CA was diagnosed in 51 (39.2%). Patients with CA had increased LV wall thickness and LV mass index. An LV remodelling pattern different from concentric LVH was found in 42% of patients with CA, and asymmetric LVH was noted in 68.6%. A model including RWT, asymmetric LVH, and LVMI showed diagnostic accuracy of 88%, sensitivity of 67% and specificity of 86% for CA detection. Traditional diagnostic criteria for CA showed high specificity but poor sensitivity. Conclusions Asymmetric LVH and remodelling patterns different from concentric LVH are common in CA. Increased LV mass index, increased RWT, and asymmetric LVH are independently associated with the diagnosis. Traditional diagnostic criteria show poor sensitivity.

Imaging a Boa Constrictor—The Incomplete Double Aortic Arch Syndrome

Incomplete double aortic arch is a rare anomaly resulting from atresia rather than complete involution in the distal left arch resulting in a non-patent fibrous cord between the left arch and descending thoracic aorta. This anatomic anomaly may cause symptomatic vascular rings, leading to stridor, wheezing, or dysphagia, requiring surgical transection of the fibrous cord. Herein, we describe an asymptomatic 59 year-old man presenting for contrast-enhanced CT angiography to assess cardiac anatomy prior to radiofrequency ablation, who was incidentally found to have an incomplete double aortic arch with hypoplasia of the left arch segment and an aortic diverticulum. Recognition of this abnormality by imaging is important to inform both corrective surgery in symptomatic patients, as well as assist in the planning of percutaneous coronary and vascular interventions.

Human Coronavirus-HKU1 Infection Among Adults in Cleveland, Ohio

Abstract Background Human coronaviruses (CoV) have been long recognized as a common cause of respiratory tract disease including severe respiratory tract illness. Coronavirus-HKU1 has been described predominantly among children less than 5 years of age in the United States with few studies characterizing the disease spectrum among adults. Methods Nasopharyngeal specimens of patients with respiratory symptoms were analyzed for CoV-HKU1 by NxTAG Respiratory Pathogen Panel multiplex assay from February 7, 2016 to April 30, 2016. Epidemiologic, clinical, and laboratory data were collected on adults (patients >18 years) whose samples screened positive. Results Of 832 adult respiratory specimens screened, 13 (1.6%) cases of CoV-HKU1 were identified. Adults age ranged between 23 and 75 years and 6 (46%) were males. All of whom had 1 or more respiratory symptoms, and 5 (38%) also reported 1 or more gastrointestinal symptoms. Eleven (85%) reported history of smoking and 5 (38%) used inhaled steroids. Seven (54%) required hospitalization, 5 (71%) of these needed supplemental oxygen, and 2 (29%) were admitted to intensive care. Median length of hospitalization was 5 days. Eight (62%) received antibiotics despite identification of CoV-HKU1. Infectious work-up in 1 patient who died did not reveal any other pathogen. In 2 (15%) CoV-HKU1-positive adults, the only viral coinfection detected was influenza A. Conclusions Coronavirus-HKU1 accounted for 1.6% of adult respiratory infections and should be considered in differential diagnosis of severe respiratory illnesses among adults.

Myocardial Amyloid Quantification with Look-Locker Magnetic Resonance Sequence in Cardiac Amyloidosis. Diagnostic Accuracy in Clinical Practice and Histological Validation

BACKGROUND Cardiac magnetic resonance (CMR) has demonstrated its utility in the noninvasive diagnosis of cardiac amyloidosis (CA). Our aim was to evaluate the ability of standard Look-Locker sequences to quantify amyloid deposition in CA. METHODS AND RESULTS Consecutive patients referred for CMR for possible CA were retrospectively evaluated. Positive cardiac biopsy and/or typical pattern of late gadolinium enhancement were required for the diagnosis of CA. Postcontrast T1 values were obtained from Look-Locker sequences and correlated with markers of severity of disease and major events. When cardiac biopsies were available, histological validation was determined. A total of 174 patients were included. A final diagnosis of CA was reached in 37.4%. Myocardial and endocardial T1 times, as well as the respective ratios with blood and skeletal muscle, were lower among patients with CA and demonstrated good diagnostic performance. The best parameters were myocardial/blood (area under the curve  0.83; P < .001) and endocardial/blood (area under the curve 0.84; P < .001) T1 ratios. Among patients with CA, no associations were found between T1 ratios either with markers of amyloid burden or with prognostic variables. However, all T1 indexes showed significant correlations with histological quantification of amyloid deposition. CONCLUSIONS Look-Looker derived postcontrast T1 shows good diagnostic accuracy to detect CA and correlation with histological amyloid burden.

A cold hard menace: A contaminated ice machine as a potential source for transmission of carbapenem-resistant Acinetobacter baumannii

Highlights:Carbapenem‐resistant Acinetobacter baumannii isolates were recovered from 3 patients, the hands of a nurse, and an ice machine water outlet and spout.Genetic typing demonstrated that the A. baumannii isolates were genetically related.Contaminated ice machines could serve as a reservoir for dissemination of multidrug‐resistant gram‐negative bacilli. &NA; During an investigation of potential sources of transmission of multidrug‐resistant gram‐negative bacilli on a spinal cord injury unit, we recovered genetically related carbapenem‐resistant Acinetobacter baumannii isolates from the stool of 3 patients, the hands of a nurse, and an ice machine water outlet spout and drain. Our findings suggest that contaminated ice machines could serve as a potential reservoir for dissemination of multidrug‐resistant gram‐negative bacilli.

How well does transfer of bacterial pathogens by culture swabs correlate with transfer by hands

&NA; In laboratory testing and in isolation rooms, pickup and transfer of health care‐associated pathogens by premoistened rayon swabs correlated well with pickup and transfer by bare hands or moistened gloves. These results suggest that swab cultures provide a useful surrogate indicator of the risk for pathogen pickup and transfer by hands.

Emergence of Resistance to Colistin During the Treatment of Bloodstream Infection Caused by Klebsiella pneumoniae Carbapenemase–Producing Klebsiella pneumoniae

Abstract We report the emergence of colistin resistance in Klebsiella pneumoniae carbapenemase (KPC)–producing Klebsiella pneumoniae after 8 days of colistin-based therapy, resulting in relapse of bloodstream infection and death. Disruption of the mgrB gene by insertion of a mobile genetic element was found to be the mechanism, which was replicated in vitro after exposure to subinhibitory concentrations of colistin and meropenem.

Hiding in Plain Sight: Contaminated Ice Machines Are a Potential Source for Dissemination of Gram-Negative Bacteria and Candida Species in Healthcare Facilities

BACKGROUND Contaminated ice machines have been linked to transmission of pathogens in healthcare facilities. OBJECTIVE To determine the frequency and sites of contamination of ice machines in multiple healthcare facilities and to investigate potential mechanisms of microorganism dispersal from contaminated ice machines to patients. DESIGN Multicenter culture survey and simulation study. SETTING The study took place in 5 hospitals and 2 nursing homes in northeastern Ohio. METHODS We cultured multiple sites on ice machines from patient care areas. To investigate potential mechanisms of microbial dispersal from contaminated ice machines, we observed the use of ice machines and conducted simulations using a fluorescent tracer and cultures. RESULTS Samples from 64 ice machines in the 5 hospitals and 2 nursing homes (range, 3-16 per facility) were cultured. Gram-negative bacilli and/or Candida spp were recovered from 100% of drain pans, 52% of ice and/or water chutes, and 72% of drain-pan grilles. During the operation of ice machines, ice often fell through the grille, resulting in splattering, with dispersal of contaminated water from the drain pan to the drain-pan grille, cups, and the hands of those using the ice machine. Contamination of the inner surface of the ice chute resulted in contamination of ice cubes exiting the chute. CONCLUSIONS Our findings demonstrate that ice machines in healthcare facilities are often contaminated with gram-negative bacilli and Candida species, and provide a potential mechanism by which these organisms may be dispersed. Effective interventions are needed to reduce the risk of dissemination of pathogenic organisms from ice machines. Infect Control Hosp Epidemiol 2018;39:253-258.

Impact of Antibiotic Treatment on the Burden of Nasal Staphylococcus aureus Among Hospitalized Patients.

We examined the impact of systemic antibiotics on the burden of nasal Staphylococcus aureus in hospitalized patients. Of 1,482 patients, 237 (16%) had nasal methicillin-susceptible S. aureus (MSSA) and 92 (6%) had nasal methicillin-resistant S. aureus (MRSA) on admission. ABSTRACT We examined the impact of systemic antibiotics on the burden of nasal Staphylococcus aureus in hospitalized patients. Of 1,482 patients, 237 (16%) had nasal methicillin-susceptible S. aureus (MSSA) and 92 (6%) had nasal methicillin-resistant S. aureus (MRSA) on admission. Treatment regimens that included agents with inhibitory activity against MRSA or MSSA significantly reduced the burden of carriage, whereas regimens lacking anti-MRSA activity, including fluoroquinolones, promoted MRSA overgrowth.

Contaminated clothing of methicillin-resistant Staphylococcus aureus (MRSA) carriers is a potential source of transmission

&NA; We examined the burden of methicillin‐resistant Staphylococcus aureus (MRSA) on the clothing of MRSA carriers in a hospital and long‐term care facility and assessed the potential for clothing to be a source of transmission. Of 50 MRSA carriers studied, 37 (74%) had MRSA recovered from clothing. For a subset of carriers with clothing contamination, transfer of MRSA from clothing to gloved hands and to a wheelchair occurred in 8 of 13 (62%) and 5 of 10 (50%) carriers, respectively. These findings suggest that measures to reduce clothing contamination should be investigated as a potential means to reduce MRSA transmission in healthcare settings.