Occupation and SARS-CoV-2 seroprevalence studies: a systematic review.

OBJECTIVE: To describe and synthesise studies of SARS-CoV-2 seroprevalence by occupation prior to the widespread vaccine roll-out. METHODS: We identified studies of occupational seroprevalence from a living systematic review (PROSPERO CRD42020183634). Electronic databases, grey literature and news media were searched for studies published during January-December 2020. Seroprevalence estimates and a free-text description of the occupation were extracted and classified according to the Standard Occupational Classification (SOC) 2010 system using a machine-learning algorithm. Due to heterogeneity, results were synthesised narratively. RESULTS: We identified 196 studies including 591 940 participants from 38 countries. Most studies (n=162; 83%) were conducted locally versus regionally or nationally. Sample sizes were generally small (median=220 participants per occupation) and 135 studies (69%) were at a high risk of bias. One or more estimates were available for 21/23 major SOC occupation groups, but over half of the estimates identified (n=359/600) were for healthcare-related occupations. 'Personal Care and Service Occupations' (median 22% (IQR 9-28%); n=14) had the highest median seroprevalence. CONCLUSIONS: Many seroprevalence studies covering a broad range of occupations were published in the first year of the pandemic. Results suggest considerable differences in seroprevalence between occupations, although few large, high-quality studies were done. Well-designed studies are required to improve our understanding of the occupational risk of SARS-CoV-2 and should be considered as an element of pandemic preparedness for future respiratory pathogens.

A randomized comparison of intraoperative indocyanine green angiography and transit-time flow measurement to detect technical errors in coronary bypass grafts.

BACKGROUND: Early coronary bypass graft failures may be preventable if identified intraoperatively. The purpose of this investigation was to compare the diagnostic accuracy of two intraoperative graft assessment techniques, transit-time ultrasound flow measurement and indocyanine green fluorescent-dye graft angiography. METHODS: Patents undergoing isolated coronary artery bypass grafting with no contraindications for postoperative angiography were enrolled in the study. Patients were randomly assigned to be evaluated with either indocyanine green angiography (Novadaq Spy angiography system; Novadaq Technologies Inc, Concord, Ontario, Canada) and then transit-time ultrasonic flow measurement (Medtronic Medi-Stim Butterfly Flowmeter TTF measurement system; Medtronic Inc, Minneapolis, Minn) or transit-time flow then indocyanine green angiography. Patients underwent x-ray angiography on postoperative day 4. The primary end point of the trial was to determine the sensitivity and specificity of the two techniques versus reference standard x-ray angiography to detect graft occlusion or greater than 50% stenosis in the graft or perianastomotic area. RESULTS: Between February 2004 and March 2005, 106 patients were enrolled and x-ray angiography was performed in 46 patients. In total, 139 grafts were reviewed with all three techniques and 12 grafts (8.2%) were demonstrated to have greater than 50% stenosis or occlusion by the reference standard. The sensitivity and specificity of indocyanine green angiography to detect greater than 50% stenosis or occlusion was 83.3% and 100%, respectively. The sensitivity and specificity of transit-time ultrasonic flow measurement to detect greater than 50% stenosis or occlusion was 25% and 98.4%, respectively. The P value for the overall comparison of sensitivity and specificity between indocyanine green angiography and transit-time flow ultrasonography was .011. The difference between sensitivity for indocyanine green angiography and transit-time flow measurement was 58% with a 95% confidence interval of 30% to 86%, P = .023. CONCLUSION: Indocyanine green angiography provides better diagnostic accuracy for detecting clinically significant graft errors than does transit-time ultrasound flow measurement.

Improving the quality of coronary bypass surgery with intraoperative angiography: validation of a new technique.

OBJECTIVES: We report a comprehensive assessment and validation of a new intraoperative angiography technique. BACKGROUND: Technical problems at the site of the distal anastomosis compromise an underappreciated proportion of coronary bypass grafts. The absence of a systematic, validated technique to verify graft patency in the operating room represents a significant breach in quality assurance. METHODS: Fluorescent indocyanine green (ICG) dye is excited with dispersed laser light to create an angiographic depiction of the graft, native vessel, and anastomosis. One-hundred twenty patients underwent ICG angiography. Angiograms were reviewed for reliability and validity studies. RESULTS: A total of 348 coronary bypass grafts were studied. Each ICG angiogram took 2.2 +/- 1.1 min to perform. The ICG angiography found 4.2% of patients had significant graft problems requiring major revision. Quality of visualization was rated according to a seven-point Likert scale (1 = worst, 7 = best). Among conduits, saphenous veins were best visualized (mean score +/- standard deviation), 6.4 +/- 1.5 versus 5.5 +/- 1.9 for internal mammary arteries and 4.4 +/- 2.3 for radial arteries (p = 0.02). Location of distal anastomosis did not influence quality of visualization. There was high inter-rater reliability for graft revision (kappa = 1.0) and graft patency (kappa = 0.97) between surgeons. Sensitivity and specificity of the ICG angiograms for graft stenosis >50% was 100% among 22 grafts also studied with X-ray angiography. CONCLUSIONS: Information from ICG angiograms led to graft revisions for technical problems in 4.2% of patients that would have otherwise gone unrecognized. Intraoperative angiography is an emerging tool for improving the quality of coronary bypass surgery.