Artificial Intelligence for Real-Time Prediction of the Histology of Colorectal Polyps by General Endoscopists.

BACKGROUND: Real-time prediction of histologic features of small colorectal polyps may prevent resection and/or pathologic evaluation and therefore decrease colonoscopy costs. Previous studies showed that computer-aided diagnosis (CADx) was highly accurate, though it did not outperform expert endoscopists. OBJECTIVE: To assess the diagnostic performance of histologic predictions by general endoscopists before and after assistance from CADx in a real-life setting. DESIGN: Prospective, multicenter, single-group study. (ClinicalTrials.gov: NCT04437615). SETTING: 6 centers across the United States. PARTICIPANTS: 1252 consecutive patients undergoing colonoscopy and 49 general endoscopists with variable experience in real-time prediction of polyp histologic features. INTERVENTION: Real-time use of CADx during routine colonoscopy. MEASUREMENTS: The primary end points were the sensitivity and specificity of CADx-unassisted and CADx-assisted histologic predictions for adenomas measuring 5 mm or less. For clinical purposes, additional estimates according to location and confidence level were provided. RESULTS: The CADx device made a diagnosis for 2695 polyps measuring 5 mm or less (96%) in 1252 patients. There was no difference in sensitivity between the unassisted and assisted groups (90.7% vs. 90.8%; P = 0.52). Specificity was higher in the CADx-assisted group (59.5% vs. 64.7%; P < 0.001). Among all 2695 polyps measuring 5 mm or less, 88.2% and 86.1% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be resected and discarded without pathologic evaluation. Among 743 rectosigmoid polyps measuring 5 mm or less, 49.5% and 47.9% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be left in situ without resection. LIMITATION: Decision making based on CADx might differ outside a clinical trial. CONCLUSION: CADx assistance did not result in increased sensitivity of optical diagnosis. Despite a slight increase, the specificity of CADx-assisted diagnosis remained suboptimal. PRIMARY FUNDING SOURCE: Olympus America Corporation served as the clinical study sponsor.

Comparative Risks of Post-ERCP Adverse Events in Patients with Asymptomatic and Symptomatic Choledocholithiasis: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is the standard of care for the management of choledocholithiasis but carries risk of complications which may result in significant morbidity and mortality. While currently available guidelines endorse the use of ERCP for the management of symptomatic common bile duct stones, the need for ERCP in incidentally found asymptomatic choledocholithiasis is more controversial, and practice varies on a geographic and institutional level. This systematic review and meta-analysis is conducted to compare post-ERCP adverse events between asymptomatic and symptomatic choledocholithiasis patients. METHODS: We searched PubMed/Embase/Web of Science databases to include all studies comparing post-ERCP outcomes between asymptomatic and symptomatic choledocholithiasis patients. The primary outcome was post-ERCP pancreatitis (PEP), while secondary outcomes included post-ERCP cholangitis, bleeding, and perforation. We calculated pooled risk ratios (RR) and 95% confidence intervals (CIs) using the Mantel-Haenszel method within a random-effect model. RESULTS: Our analysis included six observational studies, totaling 2,178 choledocholithiasis patients (392 asymptomatic and 1786 symptomatic); 53% were female. Asymptomatic patients exhibited a higher risk of PEP compared with symptomatic patients (11.7% versus 4.8%; RR 2.59, 95% CI 1.56-4.31, p ≤ 0.001). No significant difference was observed in post-ERCP cholangitis, bleeding, or perforation rates between the two groups. CONCLUSIONS: Asymptomatic patients with choledocholithiasis appear to have a higher risk of PEP than symptomatic patients, while the risk of other post-ERCP adverse events is similar between the two groups. Interventional endoscopists should thoroughly discuss potential adverse events (particularly PEP) with asymptomatic patients before performing ERCP and utilize PEP-prevention measures more liberally in this subgroup of patients.

Epidemiology and Socioeconomic Impact of Pancreatic Cancer: An Analysis of the Global Burden of Disease Study 1990-2019.

INTRODUCTION: The aim of this study is to estimate the global burden of pancreatic cancer from 1990 to 2019. METHODS: We reconstructed the Global Burden of Diseases (GBD) study results for pancreatic cancer across 204 countries and territories. Our study generated estimates for key disease burden indicators, including incidence, prevalence, mortality, and disability-adjusted life years (DALYs), and cost. Linear regression analysis of the natural logarithm of age-standardized outcomes was used to calculate annual percent change. RESULTS: In 2019, there were a total of 530,296 incident and 442,101 prevalent cases of pancreatic cancer, resulting in 531,107 deaths and 11.5 million DALYs lost. The age-standardized incidence and prevalence of pancreatic cancer has increased from 5.22 (95% CI 4.97-5.40) to 6.57 (CI 6.00-7.09) per 100,000 people per year, and 4.1 (95% CI 3.95-4.26) to 5.4 (CI 4.96-5.87), respectively. This equated to 10 million (95% CI 9.5 to 10.4 million) incident cases of pancreatic cancer. The number of DALYs lost as a result of pancreatic cancer was 225 million years (95% CI 216-234 million years). Mortality from pancreatic cancer increased over the study period from 3.7 (95% CI 3.54-3.83) to 6.9 (95% CI 6.36-7.32). Incidence, prevalence, DALYs, and mortality were higher in countries with a higher socio-demographic index. CONCLUSIONS: Pancreatic cancer is rising around the world and is associated with a high economic burden. Programs aimed at reducing modifiable risk factors are needed.

Factors predictive of hospital length of stay in patients with an index episode of acute necrotizing pancreatitis.

INTRODUCTION: Acute necrotizing pancreatitis (ANP) complicates 15 % of acute pancreatitis cases and is associated with prolonged length of stay (LOS). There are limited studies exploring potential predictors. METHODS: We carried out a retrospective study of all consecutive patients presenting to a large referral healthcare system with ANP. Patients younger than 18 years of age, without confirmed glandular necrosis and with in-hospital mortality were excluded. Poisson regression was carried out to identify potential predictors of prolonged hospital stay. RESULTS: One hundred and sixty-two patients hospitalized between December 2016 and June 2020 were included. The median LOS was 12 days (range: 1-155 days). On multivariate analysis, organ dysfunction at presentation (Incidence rate ratio (IRR) 1.21, p = 0.01) or during admission (IRR 1.32, p = 0.001), Charlson Comorbidity Index scores (IRR 1.1 per CCI point, p < 0.001), known chronic pancreatitis (IRR 1.19, p = 0.03), concurrent (non-pancreas related) infections (IRR 1.13, p = 0.04), need for enteral tube placement (IRR 3.42, p < 0.001) and in-hospital interventions (IRR 1.48-2.85 depending on intervention, p < 0.001) were associated with increased LOS. For patients in the cohort to whom this applied, delayed hospital transfers (IRR 1.02, p < 0.001) and delayed start of enteral feeds (IRR 1.01, p = 0.017) contributed to increased overall LOS. CONCLUSION: We demonstrate that multiple factors including delayed transfers to hospitals with pancreaticobiliary expertise lead to increased length of hospitalization. We suggest various strategies that can be considered to target those gaps and may have a favorable effect on LOS.

Novel 15-mm-long lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic fluid collections located ≥10 mm from the luminal wall.

BACKGROUND: Endoscopic ultrasound (EUS)-guided drainage of pancreatic fluid collections (PFCs) by cautery-enhanced lumen-apposing metal stents (LAMS) has largely been limited to collections located < 10 mm from the luminal wall. We present outcomes of the use of a novel 15-mm-long cautery-enhanced LAMS for drainage of PFCs located ≥ 10 mm away. METHODS: This international, multicenter study analyzed all adults with PFCs located ≥ 10 mm from the luminal wall who were treated by EUS-guided drainage using the 15-mm-long cautery-enhanced LAMS. The primary outcome was technical success. Secondary outcomes included clinical success (decrease in PFC size by ≥ 50 % at 30 days and resolution of clinical symptoms without surgical intervention), complications, and recurrence. RESULTS: 35 patients (median age 57 years; interquartile range [IQR] 47-64 years; 49 % male) underwent novel LAMS placement for drainage of PFCs (26 walled-off necrosis, 9 pseudocysts), measuring 85 mm (IQR 64-117) maximal diameter and located 11.8 mm (IQR 10-12.3; range 10-14) from the gastric/duodenal wall. Technical and clinical success were high (both 97 %), with recurrence in one patient (3 %) at a median follow-up of 123 days (58-236). Three complications occurred (9 %; one mild, two moderate). CONCLUSIONS: The 15-mm-long cautery-enhanced LAMS was feasible and safe for drainage of PFCs located 10-14 mm from the luminal wall.

Incidence and predictors of 30-day hospital readmissions for liver cirrhosis: insights from the United States National Readmissions Database.

BACKGROUND: Cirrhosis is associated with substantial inpatient morbidity and mortality. This study aimed to determine the trends in 30-day hospital readmission rates among patients with cirrhosis and identify factors associated with these readmissions. METHODS: We conducted a retrospective analysis of data retrieved from the Nationwide Readmissions Database to determine trends in 30-day readmission for patients discharged with a diagnosis of cirrhosis in 2010 through 2014. Multivariate logistic regression analysis was used to identify predictors of readmission. RESULTS: Among 303,346 patients identified from the database, the 30-day readmission rate for patients with a discharge diagnosis of cirrhosis was 31.4% (n=95,298). The trends in the readmission rates remained steady during the study period. On multivariate analysis, female sex, age 45 years or older, esophagogastroduodenoscopy (EGD) during admission, and disposition to a short-term care facility or skilled nursing facility protected against readmissions. In contrast, coverage by Medicaid insurance, admission during a weekend, nonalcoholic cause of cirrhosis, and history of hepatic encephalopathy and ascites were associated with readmission. CONCLUSIONS: We found an exceptionally high 30-day readmission rate in patients with cirrhosis, although it remained stable during the study period. This study identified some modifiable factors such as disposition to a short-term care facility or skilled nursing facility and patients' attendance of alcohol rehabilitation facilities that could decrease the likelihood of readmission and could inform local and national healthcare policymakers.

Ruptured idiopathic hepatic artery pseudoaneurysm causing portal vein thrombosis with portal hypertension and variceal bleeding.

Portal vein thrombosis (PVT) is an important cause of noncirrhotic portal hypertension. Noncancerous extrinsic compression of portal vein to drive PVT formation is rare, but important to identify. A 64-year-old female with idiopathic hepatic artery pseudoaneurysm (HAPA) rupture 7 months prior presented with acute-onset hematemesis and melena and was found to have prehepatic portal hypertensive variceal bleeding. Her HAPA-related retroperitoneal hematoma had resulted in portal vein compression, thrombosis, and cavernous transformation despite prompt stent graft placement across the ruptured HAPA, and required definitive treatment by transjugular intrahepatic portosystemic shunt creation with portal vein reconstruction utilizing a trans-splenic access. This case highlights the importance of interval abdominal imaging and hypercoagulability screening for noncirrhotic patients at-risk for PVT, which identified the patient as a heterozygous carrier of Factor V Leiden.

Hepatitis B Awareness and Vaccination Patterns among Healthcare Workers in Africa.

Hepatitis B virus (HBV) vaccination patterns and the understanding of its risks among healthcare workers (HCWs) is a critical step to decrease transmission. However, the depth of this understanding is understudied. We distributed surveys to HCWs in 12 countries in Africa. Surveys had nine multiple-choice questions that assessed HCWs' awareness and understanding of HBV. Participants included consultants, medical trainees, nurses, students, laboratory personnel, and other hospital workers. Surveys were completed anonymously. Fisher's exact test was used for analysis, with a P-value of < 0.05 considered significant; 1,044 surveys were collected from Kenya, Egypt, Sudan, Tanzania, Ethiopia, Uganda, Malawi, Madagascar, Nigeria, Cameroon, Ghana, and Sierra Leone. Hepatitis B virus serostatus awareness, vaccination rate, and vaccination of HCWs' children were 65%, 61%, and 48%, respectively. Medical trainees had higher serostatus awareness, vaccination rate, and vaccination of their children than HCWs in other occupations (79% versus 62%, P < 0.001; 74% versus 58%, P < 0.001; and 62% versus 45%, P = 0.006, respectively). Cost was cited as the most frequent reason for non-vaccination. West African countries were more aware of their serostatus but less often vaccinated than East African countries (79% versus 59%, P < 0.0001 and 52% versus 60%, P = 0.03, respectively). West African countries cited cost as the reason for non-vaccination more than East African countries (59% versus 40%, P = 0.0003). Our study shows low HBV serostatus awareness and vaccination rate among HCWs in Africa, and reveals gaps in the perception and understanding of HBV prevention that should be addressed to protect HCWs and improve their capacity to control HBV infection.

Clostridium difficile Infection in the Emergency Department.

INTRODUCTION: Clostridioides difficile infection (CDI) is associated with substantial emergency department (ED) and inpatient burden. To date, few studies have evaluated the ED burden of CDI. Using the Nationwide Emergency Department Sample, we evaluated trends in ED use, ED and inpatient charges, admission and mortality rates, length of stay, and independent risk factors for hospital admission and mortality after an ED visit. METHODS: Using Nationwide Emergency Department Sample for 2006 through 2014, we identified all patients with the primary diagnosis of CDI (using diagnostic codes). We determined the trends in ED visits and used survey logistic regression analysis to identify factors associated with hospital admission. RESULTS: Overall, 909,236 ED visits for CDI resulted in 817,935 admissions (90%) to the hospital. The number of visits increased from 76,709 in 2006 to 106,869 in 2014, and the admission rate decreased from 92.4% to 84.4%. ED charges adjusted for inflation went up from US$1433.0 to 2900, a significant rise even accounting for inflation. The overall length of hospital stay decreased from 7 to 5.8 days. Independent predictors of admission after ED visits included smoking, use of alcohol, and presence of multiple comorbidities. Independent risk factors for mortality in admitted patients include increasing age and presence of comorbidities. CONCLUSIONS: Although ED use for CDI increased, rates of hospital admission decreased over 9 years. Identification of predictors of admission and in-hospital mortality will help guide policies and interventions to reduce the burden on health care resources.

Incidence and Risk Factors Associated With 30-Day Readmission for Alcoholic Hepatitis.

BACKGROUND: Alcohol abuse and liver disease are associated with high rates of 30-day hospital readmission, but factors linking alcoholic hepatitis (AH) to readmission are not well understood. We aimed to determine the incidence rate of 30-day readmission for patients with AH and to evaluate potential predictors of readmission. METHODS: We used the Nationwide Readmissions Database to determine the 30-day readmission rate for recurrent AH between 2010 and 2014 and examined trends in readmissions during the study period. We also identified the 20 most frequent reasons for readmission. Multivariate survey logistic regression analysis was used to identify factors associated with 30-day readmission. RESULTS: Of the 61,750 index admissions for AH, 23.9% were readmitted within 30-days. The rate of readmission did not change significantly during the study period. AH, alcoholic cirrhosis, and hepatic encephalopathy were the most frequent reasons for readmission. In multivariate analysis female sex, leaving against medical advice, higher Charlson comorbidity index, ascites, and history of bariatric surgery were associated with earlier readmissions, whereas older age, payer type (private or self-pay/other), and discharge to skilled nursing-facility reduced this risk. CONCLUSIONS: The 30-day readmission rate in patients with AH was high and stable during the study period. Factors associated with readmission may be helpful for development of consensus-based expert guidelines, treatment algorithms, and policy changes to help decrease readmission in AH.

Incidence, Admission Rates, and Predictors, and Economic Burden of Adult Emergency Visits for Acute Pancreatitis: Data From the National Emergency Department Sample, 2006 to 2012.

INTRODUCTION: Acute pancreatitis (AP) is the most common gastroenterology-related reason for hospital admission, and a major source of morbidity and mortality in the United States. This study examines the National Emergency Database Sample, a large national database, to analyze trends in emergency department (ED) utilization and costs, risk factors for hospital admission, and associated hospital costs and length of stay (LOS) in patients presenting with AP. METHODS: The National Emergency Database Sample (2006 to 2012) was evaluated for trends in ED visits, ED charges, hospitalization rates, hospital charges, and hospital LOS in patients with primary diagnosis of AP (further subcategorized by age and etiology). A survey logistic-regression model was used to determine factors predictive of hospitalization. RESULTS: A total of 2,193,830 ED visits were analyzed. There was a nonsignificant 5.5% (P=0.07) increase in incidence of ED visits for AP per 10,000 US adults from 2006 to 2012, largely driven by significant increases in ED visits for AP in the 18 to <45 age group (+9.2%; P=0.025), AP associated with alcohol (+15.9%; P=0.001), and AP associated with chronic pancreatitis (+59.5%; P=0.002). Visits for patients aged ≥65 decreased over the time period. Rates of admission and LOS decreased during the time period, while ED and inpatient costs increased (62.1%; P<0.001 and 7.9%; P=0.0011, respectively). Multiple factors were associated with increased risk of hospital admission from the ED, with the strongest predictors being morbid alcohol use [odds ratio (OR), 4.53; P<0.0001], advanced age (age>84 OR, 3.52; P<0.0001), and smoking (OR, 1.75; P<0.0001). CONCLUSIONS: Despite a relative stabilization in the overall incidence of ED visits for AP, continued increases in ED visits and associated costs appear to be driven by younger patients with alcohol-associated and acute on chronic pancreatitis. While rates of hospitalization and LOS are decreasing, associated inflation-adjusted costs are rising. In addition, identified risk factors for hospitalization, such as obesity, alcohol use, and increased age, should be explored in further study for potential use in predictive models and clinical improvement projects.

Incidence, Admission Rates, and Economic Burden of Adult Emergency Visits for Chronic Pancreatitis: Data From the National Emergency Department Sample, 2006 to 2012.

INTRODUCTION: Chronic pancreatitis (CP) is a common reason for emergency department (ED) visits, but little research has examined ED use by patients with CP. MATERIALS AND METHODS: The Nationwide Emergency Department Sample (2006 to 2012) was interrogated to evaluate trends in adult ED visits for a primary diagnosis of CP (International Classification of Disease, 9th revision, Clinical Modification code: 577.1), the rates of subsequent hospital admission, and total charges. A survey logistic regression model was used to determine factors associated with hospitalization from the ED. RESULTS: We identified 253,753 ED visits with a primary diagnosis of CP. No significant trends in annual incidence were noted. However, the ED-to-hospitalization rates decreased by 3% per year (P<0.001) and mean ED charges after adjusting for inflation increased by 11.8% per year (P<0.001). Higher Charlson comorbidity index, current smoker status, alcohol use, and biliary-related CP were associated with hospitalization. In hospitalized patients, length of stay decreased by 2.2% per year (P=0.003) and inpatient charges increased by 2.9% per year (P=0.004). CONCLUSIONS: Patient characteristics associated with higher risk of hospitalization from the ED deserve further attention.

Endoscopic submucosal dissection of gastric tumors: A systematic review and meta-analysis.

AIM: To systematically review the medical literature in order to evaluate the safety and efficacy of gastric endoscopic submucosal dissection (ESD). METHODS: We performed a comprehensive literature search of MEDLINE, Ovid, CINAHL, and Cochrane for studies reporting on the clinical efficacy and safety profile of gastric ESD. RESULTS: Twenty-nine thousand five hundred and six tumors in 27155 patients (31% female) who underwent gastric ESD between 1999 and 2014 were included in this study. R0 resection rate was 90% (95%CI: 87%-92%) with significant between-study heterogeneity (P < 0.001) which was partly explained by difference in region (P = 0.02) and sample size (P = 0.04). Endoscopic en bloc and curative resection rates were 94% (95%CI: 93%-96%) and 86% (95%CI: 83%-89%) respectively. The rate of immediate and delayed perforation rates were 2.7% (95%CI: 2.1%-3.3%) and 0.39% (95%CI: 0.06%-2.4%) respectively while rates of immediate and delayed major bleeding were 2.9% (95%CI: 1.3-6.6) and 3.6% (95%CI: 3.1%-4.3%). After an average follow-up of about 30 mo post-operative, the rate of tumor recurrence was 0.02% (95%CI: 0.001-1.4) among those with R0 resection and 7.7% (95%CI: 3.6%-16%) among those without R0 resection. Overall, irrespective of the resection status, recurrence rate was 0.75% (95%CI: 0.42%-1.3%). CONCLUSION: Our meta-analysis, the largest and most comprehensive assessment of gastric ESD till date, showed that gastric ESD is safe and effective for gastric tumors and warrants consideration as first line therapy when an expert operator is available.

Peroral endoscopic myotomy: a meta-analysis.

Background and study aim: Peroral endoscopic myotomy (POEM) is a relatively novel minimally invasive technique that is used to treat achalasia and other esophageal motility disorders. We systematically reviewed the medical literature in order to evaluate the safety and efficacy of POEM. Methods: We performed a comprehensive review and meta-analysis of studies published up to March 2016 that reported on clinical outcomes of POEM. Five databases were searched: MEDLINE, EMBASE, Ovid, CINAHL, and Cochrane. Results: A total of 36 studies involving 2373 patients were included in the review. Clinical success (Eckardt score ≤ 3) was achieved in 98 % (95 % confidence interval [CI] 97 % - 100 %) of patients after the procedure. The mean Eckardt score decreased from 6.9 ±â€Š0.15 preoperatively to 0.77 ±â€Š0.10, 1.0 ±â€Š0.10, and 1.0 ±â€Š0.08 within 1, 6, and 12 months of treatment. In addition, there were significant decreases in the average lower esophageal sphincter pressure, integrated relaxation pressure, and the average heights of the barium column following a timed barium esophagogram after the procedure. After a mean follow-up of 8 months post-procedure, the rates of symptomatic gastroesophageal reflux, esophagitis on esophagogastroduodenoscopy, and abnormal acid exposure were 8.5 % (95 %CI 4.9 % - 13 %), 13 % (95 %CI 5.0 % - 23 %), and 47 % (95 %CI 21 % - 74 %), respectively. Conclusions: POEM appears to be safe and effective based on the large body of current evidence, and warrants consideration as first-line therapy when an expert operator is available.

Failure of antibiotics in cellulitis trials: a systematic review and meta-analysis.

OBJECTIVES: The objectives of the study are to quantify trial-to-trial variability in antibiotic failure rates, in randomized clinical trials of cellulitis treatment and to provide a point estimate for the treatment failure rate across trials. METHODS: We conducted a structured search for clinical trials evaluating antibiotic treatment of cellulitis, indexed in PubMed by August 2015. We included studies published in English and excluded studies conducted wholly outside of developed countries because the pathophysiology of cellulitis is likely to be different in such settings. Two authors reviewed all abstracts identified for possible inclusion. Of studies identified initially, 5% met the selection criteria. Two reviewers extracted data independently, and data were pooled using the Freeman-Tukey transformation under a random-effects model. Our primary outcome was the summary estimate of treatment failure across intent-to-treat and clinically evaluable participants. RESULTS: We included 19 articles reporting data from 20 studies, for a total of 3935 patients. Treatment failure was reported in 6% to 37% of participants in the 9 trials reporting intent-to-treat results, with a summary point estimate of 18% failing treatment (95% confidence interval, 15%-21%). In the 15 articles evaluating clinically evaluable participants, treatment failure rates ranged from 3% to 42%, and overall, 12% (95% confidence interval, 10%-14%) were designated treatment failures. CONCLUSIONS: Treatment failure rates vary widely across cellulitis trials, from 6% to 37%. This may be due to confusion of cellulitis with its mimics and perhaps problems with construct validity of the diagnosis of cellulitis. Such factors bias trials toward equivalence and, in routine clinical care, impair quality and antibiotic stewardship. Objective diagnostic tools are needed.

Association between fine particulate matter exposure and subclinical atherosclerosis: A meta-analysis.

BACKGROUND: Epidemiological studies in humans that have evaluated the association between fine particulate matter (PM2.5) and atherosclerosis have yielded mixed results. DESIGN: In order to further investigate this relationship, we conducted a comprehensive search for studies published through May 2014 and performed a meta-analysis of all available observational studies that investigated the association between PM2.5 and three noninvasive measures of clinical and subclinical atherosclerosis: carotid intima media thickness, arterial calcification, and ankle-brachial index. METHODS AND RESULTS: Five reviewers selected studies based on predefined inclusion criteria. Pooled mean change estimates and 95% confidence intervals were calculated using random-effects models. Assessment of between-study heterogeneity was performed where the number of studies was adequate. Our pooled sample included 11,947 subjects for carotid intima media thickness estimates, 10,750 for arterial calcification estimates, and 6497 for ankle-brachial index estimates. Per 10 µg/m(3) increase in PM2.5 exposure, carotid intima media thickness increased by 22.52 µm but this did not reach statistical significance (p = 0.06). We did not find similar associations for arterial calcification (p = 0.44) or ankle-brachial index (p = 0.85). CONCLUSION: Our meta-analysis supports a relationship between PM2.5 and subclinical atherosclerosis measured by carotid intima media thickness. We did not find a similar relationship between PM2.5 and arterial calcification or ankle-brachial index, although the number of studies was small.