Citations

Abstract Aims Left atrial (LA) function is impaired in heart failure with preserved ejection fraction (HFpEF) and predicts disease severity and risk of adverse outcome. We sought to evaluate whether LA strain could enhance diagnosis of HFpEF. Methods and results Consecutive patients with unexplained exertional dyspnoea and image quality suitable for measuring LA strain underwent invasive cardiopulmonary exercise testing to ascertain the presence of HFpEF or non-cardiac causes of dyspnoea (NCD). LA reservoir strain was measured in all patients, while LA conduit and booster strain were measured in patients with sinus rhythm. LA strain was measurable in 363 of 378 examinations (96.5%; HFpEF: 238, NCD: 125). LA reservoir strain (29 ± 16% vs. 40 ± 13%, P < 0.0001) and conduit strain (18 ± 10% vs. 22 ± 10%, P = 0.0001) were significantly impaired in HFpEF compared to NCD. Of all echocardiographic indices, LA reservoir strain best discriminated HFpEF from NCD [area under the curve (AUC) 0.719, P < 0.0001], outperforming E/e' (AUC difference +0.117, P < 0.0001), LA enlargement (+0.090, P = 0.001), tricuspid regurgitation velocity > 2.8 m/s (+0.082, P = 0.0085), left ventricular hypertrophy (+0.0159, P < 0.0001) and left ventricular global longitudinal strain (+0.0198, P < 0.0001). Indexing LA reservoir strain to estimated LA pressure (E/e') as a surrogate for LA compliance further improved diagnostic performance (AUC 0.772, P < 0.0001; +0.053 compared to LA reservoir strain alone, P = 0.003). Conclusion Left atrial reservoir strain may provide enhanced diagnostic accuracy beyond conventional echocardiographic measures to discriminate HFpEF from NCD. Further study is required to verify the diagnostic utility of LA strain.

AbstractObjectivesWe sought to validate a deep learning algorithm designed to predict an ejection fraction (EF) less than or equal to 35% based on the 12‐lead electrocardiogram (ECG) in a large prospective cohort.BackgroundPatients undergoing routine ECG may have undetected left ventricular (LV) dysfunction that warrants further echocardiographic assessment. However, identification of these patients can be challenging.MethodsWe applied the algorithm to all ECGs interpreted by the Mayo Clinic ECG laboratory in September 2018. The performance of the algorithm was tested among patients with recent echocardiographic assessments of LV function. We also applied the algorithm in patients with no recent echocardiographic assessments of LV function to determine the rate of new “positive screens.”ResultsAmong 16 056 adult patients who underwent routine ECG, 8600 (age 67.1 ± 15.2 years, 45.6% male), had a transthoracic echocardiogram (TTE) and 3874 patients had a TTE and ECG less than 1 month apart. Among these patients, the algorithm was able to detect an EF less than or equal to 35% with 86.8% specificity, 82.5% sensitivity, and 86.5% accuracy, (area under the curve, 0.918). Among 474 “false‐positives screens,” 189 (39.8%) had an EF of 36% to 50%. Among patients with no prior TTE, the algorithm identified 3.5% of the patients with suspected EF less than or equal to 35%. Exploratory analysis suggests false positives could be reduced by assessing NT‐pro‐BNP after the initial “positive screen.”ConclusionsA deep learning algorithm detected depressed LV function with good accuracy in routine practice. Further studies are needed to validate the algorithm in patients with no prior echocardiogram and to assess the impact on echocardiography utilization, cost, and clinical outcomes.

PURPOSE Background parenchymal uptake (BPU), which describes the level of radiotracer uptake in normal fibroglandular tissue on molecular breast imaging (MBI), has been identified as a breast cancer risk factor. Our objective was to develop and validate a deep learning model using image convolution to automatically categorize BPU on MBI. METHODS MBI examinations obtained for clinical and research purposes from 2004 to 2015 were reviewed to classify the BPU pattern using a standardized five-category scale. Two expert radiologists provided interpretations that were used as the reference standard for modeling. The modeling consisted of training and validating a convolutional neural network to predict BPU. Model performance was summarized in data reserved to test the performance of the algorithm at the per-image and per-breast levels. RESULTS Training was performed on 24,639 images from 3,133 unique patients. The model performance on the withheld testing data (6,172 images; 786 patients) was evaluated. Using direct matching on the predicted classification resulted in an accuracy of 69.4% (95% CI, 67.4% to 71.3%), and if prediction within one category was considered, accuracy increased to 96.0% (95% CI, 95.2% to 96.7%). When considering the breast-level prediction of BPU, the accuracy remained strong, with 70.3% (95% CI, 68.0% to 72.6%) and 96.2% (95% CI, 95.3% to 97.2%) for the direct match and allowance for one category, respectively. CONCLUSION BPU provided a robust target for training a convolutional neural network. A validated computer algorithm will allow for objective, reproducible encoding of BPU to foster its integration into risk-stratification algorithms.

Diverse acute neurological injuries may cause acute cardiopulmonary events including neurogenic pulmonary edema (NPE) and neurogenic stunned myocardium (NSM). The mechanism is probably mediated by sympathetic nervous system activation. Focal central nervous system (CNS) lesions, such as demyelinating lesions in multiple sclerosis (MS), may also cause cardiopulmonary disturbances. We aim to review the acute cardiopulmonary events associated with MS relapses. We performed a literature search using PubMed, and selected case reports of acute cardiac and/or pulmonary events related to MS exacerbations. We grouped these events into three categories: 1) NPE with normal cardiac function; 2) NSM and Takotsubo cardiomyopathy (TTC); 3) coexisting myocardial dysfunction and pulmonary edema. In some cases, cardiac and pulmonary symptoms preceded the onset of neurological symptoms. The majority of cases were associated with acute demyelinating lesions located in the medulla. Acute brainstem MS relapses, with demyelinating lesions affecting the medulla, may cause acute cardiac and pulmonary events presumably secondary to sympathetic hyperstimulation. Specific regions in the medulla that regulate cardiac function, systemic blood pressure and pulmonary hydrostatic pressure seem to be responsible for these events.

Objectives The aim of this study was to investigate the impact on metal artifacts and dose efficiency of using a tin filter in combination with high-energy threshold (TH) images of a photon-counting detector (PCD) computed tomography (CT) system. Materials and Methods A 3D-printed spine with pedicle screws was scanned on a PCD-CT system with and without tin filtration. Image noise and severity of artifacts were measured for low-energy threshold (TL) and TH images. In a prospective, institutional review board–approved, Health Insurance Portability and Accountability Act-compliant study, 20 patients having a clinical energy-integrating detector (EID) CT were scanned on a PCD-CT system using tin filtration. Images were reviewed by 3 radiologists to evaluate visualization of anatomic structures, diagnostic confidence, and image preference. Artifact severity and image noise were measured. Wilcoxon signed rank was used to test differences between PCD-CT TH and EID-CT images. Results Phantom TH images with tin filtration reduced metal artifacts and had comparable noise (32 HU) to TL images (29 HU) acquired without tin filtration. Visualization scores for the cortex, trabeculae, and implant-trabecular interface from PCD-CT TH images (4.4 ± 0.9, 4.4 ± 1.0, and 4.4 ± 1.0) were significantly higher (P < 0.0001) than EID-CT images (3.3 ± 1.3, 3.3 ± 1.2, and 3.3 ± 1.6). A strong preference was shown for PCD-CT TH images due to improved diagnostic confidence and decreased artifact severity. Noise in PCD-CT TH images (93 ± 41 HU) was significantly lower than that in EID-CT images (133 ± 92 HU, P < 0.05). Conclusions Threshold high images acquired with tin filtration on PCD-CT demonstrated a substantial decrease in metal artifacts and an increase in dose efficiency compared with EID-CT.

AbstractBackgroundMany healthcare facilities and providers prohibit blenderized tube feeding (BTF) for patients who request it due to concerns of high microbial load. The current project compared microbial loads of a standard ready‐to‐feed polymeric commercial formula (CF), a BTF made using baby food (BTF‐BF), and a BTF prepared from blending whole food (BTF‐WF), following food safety standards expected of U.S. hospitals.MethodsThree tube‐feeding formulas (CF, BTF‐BF, BTF‐WF) were prepared in a U.S. hospital and delivered in vitro to an unoccupied patient room. Samples were collected at zero hour, 2 hours, and 4 hours and compared for growth of aerobic microorganisms, Staphylococus aureus, coliforms, and Escherichia coli. The experiment was conducted in triplicate, 1 week apart.ResultsNo S. aureus or coliform/E. coli were detected at any time point following preparation, and total bacterial count was well below acceptable limits. All 3 feeding formulas at zero hour, 2 hours, and 4 hours for each of the 3 sampling dates were acceptable for human consumption.ConclusionJudicious BTF recipe selection and adherence to safe food handling provide a safe feeding substrate equivalent to CF in the hospital setting. Due to increased use and interest in BTF by patients and their caregivers, healthcare facilities may need to reexamine their policies prohibiting BTF use.