ORCID Profile
0000-0001-9344-8522
Current Organisations
University of Toronto
,
University Health Network
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Publisher: BMJ
Date: 09-10-2018
DOI: 10.1136/THORAXJNL-2018-212021
Abstract: The importance of circadian factors in managing patients is poorly understood. We present two retrospective cohort studies showing that lungs reperfused between 4 and 8 AM have a higher incidence (OR 1.12 95% CI 1.03 to 1.21 p=0.01) of primary graft dysfunction (PGD) in the first 72 hours after transplantation. Cooling of the donor lung, occurring during organ preservation, shifts the donor circadian clock causing desynchrony with the recipient. The clock protein REV-ERBα directly regulates PGD biomarkers explaining this circadian regulation while also allowing them to be manipulated with synthetic REV-ERB ligands.
Publisher: BMJ
Date: 12-2022
DOI: 10.1136/BMJRESP-2022-001396
Abstract: Spirometry and plethysmography are the gold standard pulmonary function tests (PFT) for diagnosis and management of lung disease. Due to the inaccessibility of plethysmography, spirometry is often used alone but this leads to missed or misdiagnoses as spirometry cannot identify restrictive disease without plethysmography. We aimed to develop a deep learning model to improve interpretation of spirometry alone. We built a multilayer perceptron model using full PFTs from 748 patients, interpreted according to international guidelines. Inputs included spirometry (forced vital capacity, forced expiratory volume in 1 s, forced mid-expiratory flow 25–75 ), plethysmography (total lung capacity, residual volume) and biometrics (sex, age, height). The model was developed with 2582 PFTs from 477 patients, randomly ided into training (80%), validation (10%) and test (10%) sets, and refined using 1245 previously unseen PFTs from 271 patients, split 50/50 as validation (136 patients) and test (135 patients) sets. Only one test per patient was used for each of 10 experiments conducted for each input combination. The final model was compared with interpretation of 82 spirometry tests by 6 trained pulmonologists and a decision tree. Accuracies from the first 477 patients were similar when inputs included biometrics+spirometry+plethysmography (95%±3%) vs biometrics+spirometry (90%±2%). Model refinement with the next 271 patients improved accuracies with biometrics+pirometry (95%±2%) but no change for biometrics+spirometry+plethysmography (95%±2%). The final model significantly outperformed (94.67%±2.63%, p .01 for both) interpretation of 82 spirometry tests by the decision tree (75.61%±0.00%) and pulmonologists (66.67%±14.63%). Deep learning improves the diagnostic acumen of spirometry and classifies lung physiology better than pulmonologists with accuracies comparable to full PFTs.
Publisher: Elsevier BV
Date: 08-2023
Publisher: European Respiratory Society (ERS)
Date: 25-06-2021
DOI: 10.1183/13993003.03639-2020
Abstract: The diffusing capacity of the lung for carbon monoxide corrected for haemoglobin ( D LCOcor ) measures gas movement across the alveolar–capillary interface. We hypothesised that D LCOcor is a sensitive measure of injurious allograft processes disrupting this interface. To determine the prognostic significance of the D LCOcor trajectory on chronic lung allograft dysfunction (CLAD) and survival. A retrospective analysis was conducted of all bilateral lung transplant recipients at a single centre, between January 1998 and January 2018, with one or more D LCOcor measurements. Low baseline D LCOcor was defined as the failure to achieve a D LCOcor % predicted. Drops in D LCOcor were defined as % below recent baseline. 1259 out of 1492 lung transplant recipients were included. The median (range) time to peak D LCOcor was 354 (181–737) days and the mean± sd D LCOcor was 80.2±21.2% pred. Multivariable analysis demonstrated that low baseline D LCOcor was significantly associated with death (hazrd ratio (HR) 1.68, 95% CI 1.27–2.20 p .001). Low baseline D LCOcor was not independently associated with CLAD after adjustment for low baseline forced expiratory volume in 1 s or forced vital capacity. Any D LCOcor declines ≥15% were significantly associated with death, independent of concurrent spirometric decline. Lower percentage predicted D LCOcor values at CLAD onset were associated with shorter post-CLAD survival (HR 0.75 per 10%-unit change, p .01). Low baseline D LCOcor and post-transplant declines in D LCOcor were significantly associated with survival, independent of spirometric measurements. We propose that D LCOcor testing may allow identification of a subphenotype of baseline and chronic allograft dysfunction not captured by spirometry. There may be benefit in routine monitoring of D LCOcor after lung transplantation to identify patients at risk of poor outcomes.
No related grants have been discovered for Chung-Wai Chow.