Pulmonary arteriovenous malformations: diagnosis

Pulmonary arteriovenous malformations (PAVMs) are rare, abnormal low resistance vascular structures that connect a pulmonary artery to a pulmonary vein, thereby bypassing the normal pulmonary capillary bed and resulting in an intrapulmonary right-to-left shunt. The spectrum of PAVMs extends from microscopic lesions causing profound hypoxemia and ground glass appearance on computed tomography (CT) but with normal catheter angiographic findings to classic pulmonary aneurysmal connections that abnormally connect pulmonary veins and arteries. These malformations most commonly are seen in hereditary hemorrhagic telangiectasia (HHT). They are rarely due to secondary conditions such as post congenital heart disease surgery or hepatopulmonary syndrome (HPS). The main complications of PAVM result from intrapulmonary shunt and include stroke, brain abscess, and hypoxemia. Local pulmonary complications include PAVM rupture leading to life-threatening hemoptysis or hemothorax. The preferred screening test for PAVM is transthoracic contrast echocardiography (TTCE). CT has become the gold standard imaging test to establish the presence of PAVM. Endovascular occlusion of the feeding artery is the treatment of choice. Collateralization and recanalization of PAVM following treatment may occur, and hence long term clinical and imaging follow-up is required to assess PAVM enlargement and PAVM reperfusion.

Do Current Lung Cancer Screening Guidelines Apply for Populations With High Prevalence of Granulomatous Disease? Results From the First Brazilian Lung Cancer Screening Trial (BRELT1)

BACKGROUND

Low-dose computed tomography (LDCT) screening for lung cancer has been demonstrated to be effective in reducing cancer mortality. However, these studies have not been undertaken in countries where the incidence of granulomatous disease is high. The First Brazilian Lung Cancer Screening Trial (BRELT1) has completed initial accrual and is now in the follow-up phase. We present results from the initial prevalence round of screening.

METHODS

The inclusion criteria were the same as those for the National Lung Cancer Screening Trial (NLST). Pulmonary nodules larger than 4 mm were considered positive and required evaluation by a multidisciplinary team. Indeterminate nodules were evaluated with fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) or biopsy when indicated. Statistical analysis was performed with Fisher's exact test to compare our positive findings with those of the NLST.

RESULTS

From January 2013 to July 2014, 790 participants were enrolled. Positive LDCT scans were reported in 312 (39.4%) participants, with a total of 552 nodules larger than 4 mm. The comparison between positive findings in the NLST (7,191 of 26,722 cases) and those in the BRELT1 (312 of 790 cases) showed a significant difference (p < 0.001). The positive predictive value was lower in BRELT1 than in the NLST (3.2% versus 3.8%, respectively). Follow-up imaging was indicated in 278 of 312 (89.1%) participants; 35 procedures were performed in 25 participants. In 15 cases, benign lesions were diagnosed. Non-small-cell lung cancer (NSCLC) was diagnosed in 10 patients (prevalence of 1.3%). In 8 patients (stage IA/IB disease), treatment was by resection only, in 1 patient neoadjuvant chemotherapy was used (stage IIIA), and in 1 patient advanced disease was diagnosed (stage IV).

CONCLUSIONS

Using NSLT criteria, a larger number of patients had positive scans (nodules), compared with previous lung cancer screening studies. However, the number of participants requiring surgical biopsy procedures and who were ultimately identified as having cancer was similar to other reports. This supports the role of screening in patient populations with a high incidence of granulomatous inflammation.

Absorption of oxybutynin from vaginal inserts: drug blood levels and the response of the rabbit bladder

OBJECTIVES

Oxybutynin has been used for treatment of urge urinary incontinence for more than 20 years. However, one of the major problems with its use is uncomfortable anticholinergic side effects that can lead to discontinuation of treatment. Alternative forms of drug administration may reduce side effects and thus improve patient compliance.

METHODS

A cylinder-shaped, curved silicone elastomer insert containing oxybutynin was anchored in the vagina of female rabbits. The inserts were designed to release oxybutynin at rates of 0.5, 1.0, and 5.0 mg/day, respectively. Blood drug and metabolite levels were monitored for 1 to 7 days and cystometry was carried out after 7 days of treatment.

RESULTS

There was a consistent dose-dependent absorption of the oxybutynin resulting in stable plasma concentrations by 3 days. Levels of N-desethyloxybutynin, the active metabolite that is thought to be responsible for side effects, were less than 1.0 ng/mL in all groups. The cystometrograms showed a decrease in the detrusor pressures for the higher oxybutynin groups and a dose-dependent decrease in micturition pressure. The vaginal wall in contact with the insert showed no irritation.

CONCLUSIONS

The inserts produced stable blood levels and released sufficient amounts of oxybutynin to have measurable effects on the bladder. There was no irritating effect of the insert on the vaginal wall after a 1-week treatment. Vaginal inserts containing oxybutynin may be an interesting alternative method for the chronic delivery of oxybutynin.

Deep Learning-Based COVID-19 Pneumonia Classification Using Chest CT Images: Model Generalizability

Since the outbreak of the COVID-19 pandemic, worldwide research efforts have focused on using artificial intelligence (AI) technologies on various medical data of COVID-19-positive patients in order to identify or classify various aspects of the disease, with promising reported results. However, concerns have been raised over their generalizability, given the heterogeneous factors in training datasets. This study aims to examine the severity of this problem by evaluating deep learning (DL) classification models trained to identify COVID-19-positive patients on 3D computed tomography (CT) datasets from different countries. We collected one dataset at UT Southwestern (UTSW) and three external datasets from different countries: CC-CCII Dataset (China), COVID-CTset (Iran), and MosMedData (Russia). We divided the data into two classes: COVID-19-positive and COVID-19-negative patients. We trained nine identical DL-based classification models by using combinations of datasets with a 72% train, 8% validation, and 20% test data split. The models trained on a single dataset achieved accuracy/area under the receiver operating characteristic curve (AUC) values of 0.87/0.826 (UTSW), 0.97/0.988 (CC-CCCI), and 0.86/0.873 (COVID-CTset) when evaluated on their own dataset. The models trained on multiple datasets and evaluated on a test set from one of the datasets used for training performed better. However, the performance dropped close to an AUC of 0.5 (random guess) for all models when evaluated on a different dataset outside of its training datasets. Including MosMedData, which only contained positive labels, into the training datasets did not necessarily help the performance of other datasets. Multiple factors likely contributed to these results, such as patient demographics and differences in image acquisition or reconstruction, causing a data shift among different study cohorts.

Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

A three-day doxycycline regimen for treatment of gonorrhea

Patients with uncomplicated gonorrhea were given three 300-mg capsules of doxycycline, one of which was to be taken after the heaviest meal of the day, on each of three consecutive days. A total of 560 men and women were treated by this method. Of the 355 patients who returned for tests of cure within seven to ten days, all but seven (2%) responded favorably to the treatment. The effectiveness of the regimen was similar to that of other accepted treatments. Adverse effects were inconsequential or absent, providing that the medication was taken after meals. This treatment option simplifies considerably the directions to be followed by the patient and minimizes the risk of noncompliance in the treatment of gonorrhea with tetracyclines.

Genetic etiology of lung cancer

Although the clinical management of lung cancer has not changed substantially over the past decade, this same time period has witnessed exciting new developments concerning the origins of this disease. These findings support the hypothesis that lung cancer, as well as other common adult tumors, arise as a result of somatic mutations to a specific group of cellular genes referred to as oncogenes and tumor suppressor genes. New strategies for the prevention and treatment of lung cancer will emerge as we identify the mechanisms that control mutation rates for these target genes and gain a better understanding of the role these genes play in coordinating normal cell growth and differentiation.

Measurement and Application of Incidentally Detected Coronary Calcium: JACC Review Topic of the Week

Coronary artery calcium (CAC) scoring is a powerful tool for atherosclerotic cardiovascular disease risk stratification. The nongated, noncontrast chest computed tomography scan (NCCT) has emerged as a source of CAC characterization with tremendous potential due to the high volume of NCCT scans. Application of incidental CAC characterization from NCCT has raised questions around score accuracy, standardization of methodology including the possibility of deep learning to automate the process, and the risk stratification potential of an NCCT-derived score. In this review, the authors aim to summarize the role of NCCT-derived CAC in preventive cardiovascular health today as well as explore future avenues for eventual clinical applicability in specific patient populations and broader health systems.