Neal Shahidi

Diagnostic accuracy of echocardiography for pulmonary hypertension: a systematic review and meta-analysis

Context Right heart catheterisation is the gold standard for the diagnosis of pulmonary hypertension. However, echocardiography is frequently used to screen for this disease and monitor progression over time because it is non-invasive, widely available and relatively inexpensive. Objective To perform a systematic review and quantitative meta-analysis to determine the correlation of pulmonary pressures obtained by echocardiography versus right heart catheterisation and to determine the diagnostic accuracy of echocardiography for pulmonary hypertension. Data sources MEDLINE, EMBASE, PapersFirst, the Cochrane collaboration and the Cochrane Register of controlled trials were searched and were inclusive as of February 2010. Study selection Studies were only included if a correlation coefficient or the absolute number of true-positive, false-negative, true-negative and false-positive observations was available, and the ‘reference standards’ were described clearly. Data extraction Two reviewers independently extracted the data from each study. Quality was assessed with the quality assessment for diagnostic accuracy studies. A random effects model was used to obtain a summary correlation coefficient and the bivariate model for diagnostic metaanalysis was used to obtain summary sensitivity and specificity values. Results 29 studies were included in the meta-analysis. The summary correlation coefficient between systolic pulmonary arterial pressure estimated from echocardiography versus measured by right heart catheterisation was 0.70 (95% CI 0.67 to 0.73; n=27). The summary sensitivity and specificity for echocardiography for diagnosing pulmonary hypertension was 83% (95% CI 73 to 90) and 72% (95% CI 53 to 85; n=12), respectively. The summary diagnostic OR was 13 (95% CI 5 to 31). Conclusions Echocardiography is a useful and noninvasive modality for initial measurement of pulmonary pressures but due to limitations, right heart catheterisation should be used for diagnosing and monitoring pulmonary hypertension.

Performance of interferon-gamma release assays in patients with inflammatory bowel disease: A systematic review and meta-analysis

Background: Guidelines mandate screening for latent tuberculosis infection (LTBI) prior to anti‐tumor necrosis factor (anti‐TNF) therapy in patients with inflammatory bowel disease (IBD). However, many are already on immunosuppressive therapy (IST) that may affect the precision of the Tuberculin skin test (TST). Our aim was to assess the performance of the new interferon‐gamma release assays (IGRAs) to detect LTBI in patients with IBD. Methods: MEDLINE and EMBASE were searched (up to June 2011) to identify studies evaluating the performance of IGRAs (QuantiFERON‐TB Gold [QFT‐2G], QuantiFERON‐TB Gold In‐Tube [QFT‐3G] and T‐SPOT.TB) in individuals with IBD. Forest plots and pooled estimates using random effects models were created where applicable. Results: Nine unique studies encompassing 1309 patients with IBD were included for analysis. The pooled concordance between the TST and QFT‐2G/QFT‐3G was 85% (95% confidence interval [CI] 77%–90%). The concordance of the TST and TSPOT.TB was 72% (95% CI 64%–78%). Studies assessing agreement reported more IGRA−/TST+ results versus IGRA+/TST− results. The pooled percentage of indeterminate results was 5% (95% CI 2%–9%) for QFT‐2G/QFT‐3G. TSPOT.TB showed similar results. Both positive QFT‐2G/QFT‐3G results (pooled odds ratio [OR] 0.37, 95% CI 0.16–0.87) and positive TST results (pooled OR 0.28, 95% CI 0.10–0.80) were significantly influenced by IST (both P = 0.02). Conclusions: While it remains difficult to determine superiority between the IGRAs and the TST, both are negatively affected by IST. Therefore, screening prior to initiation of IST should be considered. Nevertheless, it is imperative that all patients receive screening prior to anti‐TNF therapy. (Inflamm Bowel Dis 2012;)

Factors Associated With Positive Findings From Capsule Endoscopy in Patients With Obscure Gastrointestinal Bleeding

BACKGROUND & AIMS Capsule endoscopy (CE) is used most frequently to identify causes of obscure gastrointestinal bleeding (OGIB). Identifying factors associated with the detection of lesions by CE could improve resource utilization and thereby improve patient selection for CE examination. We sought to identify clinical factors associated with positive findings from CE in patients with OGIB. METHODS We analyzed data from 698 CE procedures performed between December 2001 and April 2011 at St Pauls Hospital, Vancouver, Canada (50.3% of patients were female; mean age, 63.4 years). A positive finding was defined as a lesion that was believed to be the source of the bleeding (ulceration, mass lesion, vascular lesion, or visible blood). Univariate and multivariate logistic regression analyses were used to correlate demographic and clinical parameters with positive findings. RESULTS A lesion believed to be the cause of bleeding was identified in 42% of cases. In univariate analysis, the number of esophagogastroduodenoscopies (EGDs), the presence of connective tissue disease or diabetes with end-organ damage, Charlson comorbidity index scores, and increasing transfusion requirements were significantly associated with identification of causative pathology from CE (all P < .027). In multivariate analysis, increasing number of EGDs (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.00-1.37), increasing transfusion requirements (3-9 units: OR, 1.70; 95% CI, 1.08-2.66, and ≥10 units: OR, 2.72; 95% CI, 1.69-4.37), and connective tissue disease (OR, 2.24; 95% CI, 1.14-4.41) were all significantly associated with identification of positive findings by using CE (all P < .045). CONCLUSIONS Patients with a higher number of precapsule EGDs or transfusions, or connective tissue disease, are superior candidates for analysis of OGIB by CE.

Establishing the learning curve for achieving competency in performing colonoscopy: a systematic review.

Colonoscopy (CSPY) allows competent endoscopists to safely, tolerably, and accurately examine the entire colon, thus facilitating the diagnosis of colonic diseases as well as the performance of therapeutic interventions. It can be technically demanding and requires significant time and practice to master the psychomotor and cognitive aspects of the procedure. Therefore, with a significant number of graduating gastroenterology and surgical trainees expected to perform this procedure as a core component of their future practice, the need for appropriate training to allow for the acquisition of competence is critical. With this in mind, 2 questions arise: (1) what is procedural competence in this setting and (2) at what point do trainees become competent? Unfortunately, even though CSPY allows for objective assessment, the definition of competence remains difficult to delineate. Arguably the most frequently referenced CSPY performance marker is the cecal intubation rate (CIR). Because cecal intubation is a critical component to defining a complete CSPY, it is often reported as a prerequisite for determining competence. The American Society for Gastrointestinal Endoscopy (ASGE) in conjunction with the American College of Gastroenterology (ACG) published quality indicators to help define competence. These, alongside other recommendations, suggest at least a 90% CIR in all cases. However, cecal intubation is only 1 component of a complete CSPY and alone does not sufficiently define competency. Regarding the number of procedures required to become competent, the first guidelines were based on expert opinion. Subsequently, with the emergence of a pivotal study by Cass et al, the ASGE recommended that trainees complete a minimum of 140 CSPYs before competence can be assessed. However, both references above are now relatively outdated, and as additional studies

Effect of longer battery life on small bowel capsule endoscopy

AIM To determine if longer battery life improves capsule endoscopy (CE) completion rates. METHODS A retrospective study was performed at a tertiary, university-affiliated hospital in Vancouver, Canada. Patients who underwent CE with either PillCam™ SB2 or SB2U between 01/2010 and 12/2013 were considered for inclusion. SB2 and SB2U share identical physical dimensions but differ in their battery lives (8 h vs 12 h). Exclusion criteria included history of gastric or small bowel surgery, endoscopic placement of CE, interrupted view of major landmarks due to technical difficulty or significant amount of debris, and repeat CE using same system. Basic demographics, comorbidities, medications, baseline bowel habits, and previous surgeries were reviewed. Timing of major landmarks in CE were recorded, and used to calculate gastric transit time, small bowel transit time, and total recording time. A complete CE study was defined as visualization of cecum. Transit times and completion rates were compared. RESULTS Four hundred and eight patients, including 208 (51.0%) males, were included for analysis. The mean age was 55.5 ± 19.3 years. The most common indication for CE was gastrointestinal bleeding (n = 254, 62.3%), followed by inflammatory bowel disease (n = 86, 21.1%). There was no difference in gastric transit times (group difference 0.90, 95%CI: 0.72-1.13, P = 0.352) and small bowel transit times (group difference 1.07, 95%CI: 0.95-1.19, P = 0.261) between SB2U and SB2, but total recording time was about 14% longer in the SB2U group (95%CI: 10%-18%, P < 0.001) and there was a corresponding trend toward higher completion rate (88.2% vs 93.2%, OR = 1.78, 95%CI 0.88-3.63, P = 0.111). There was no statistically significant difference in the rates of positive findings (OR = 0.98, 95%CI: 0.64-1.51, P = 0.918). CONCLUSION Extending the operating time of CE may be a simple method to improve completion rate although it does not affect the rate of positive findings.

Achieving asthma control in patients with moderate disease

Patients with moderate asthma are symptomatic on an ongoing basis. They are usually treated initially with low-dose inhaled corticosteroids (ICSs) supplemented with a short-acting bronchodilator as a rescue medication. Most steroid-naive patients will achieve good control with this strategy. For patients in whom adherence, inhaler technique, environmental control, and comorbidities have been addressed but who still have uncontrolled symptoms, the addition of a long-acting beta-adrenergic agonist should be considered. Some patients might require a higher dose of ICS. Leukotriene receptor antagonists might be considered as alternate initial therapy or as an add-on to maintenance therapy with an ICS. All patients should receive a structured education program emphasizing the need for ongoing maintenance treatment, even when control is achieved. Patients should also be provided with a written action plan that clearly explains which additional anti-inflammatory therapy should be taken if asthma symptoms worsen. The most effective strategy in this situation has been shown to be the quadrupling of the maintenance dose of ICS.

Current recommendations for the treatment of mild asthma.

Patients suffering from mild asthma are divided into intermittent or persistent classes based on frequency of symptoms and reliever medication usage. Although these terms are used as descriptors, it is important to recognize the approach of focusing on asthma control in managing asthma patients. Beta-agonists are considered first-line therapy for intermittent asthmatics. If frequent use of beta-agonists occurs more than twice a week, controller therapy should be considered. For persistent asthma, low-dose inhaled corticosteroids are recommended in addition to reliever medication. Compliance to regular therapy can pose problems for disease management, and while intermittent controller therapy regimens have been shown to be effective, it is imperative to stress the value of regular therapy especially if an exacerbation occurs. It is also important when such an approach is adopted that there is regular re-evaluations of asthma control. This is because regular anti-inflammatory therapy may become necessary if symptoms become more persistent. Other therapies are seldom needed. Antileukotrienes can be considered an option for mild asthma; however, studies have shown that they are not as effective as inhaled corticosteroids. Aside from therapy, patient education, which includes a written action plan, should be a component of the patient’s strategy for disease management.

The role of vedolizumab in patients with moderate-to-severe Crohn’s disease and ulcerative colitis

Vedolizumab, an α4β7-integrin antagonist, is the first gut-selective monoclonal antibody that has been approved for the treatment of moderate-to-severe ulcerative colitis and Crohn’s disease in many countries in the world. However, questions still remain regarding its appropriate use and placement in current treatment algorithms. Therefore, we sought out to evaluate the existing literature on the use of vedolizumab in inflammatory bowel disease. From inception to 21 June 2015 we searched MEDLINE for phase III randomized control trials assessing the utility of vedolizumab in inflammatory bowel disease, of which three were identified. The GEMINI trials demonstrate that vedolizumab is an effective and safe treatment for patients suffering from moderate-to-severe ulcerative colitis (GEMINI I) and Crohn’s disease (GEMINI II and III). However, further studies are needed comparing its efficacy directly with anti-tumor necrosis factor therapies to allow for further delineation of current treatment algorithms as well as ensuring its long-term safety profile.

Vedolizumab for the treatment of ulcerative colitis

Introduction: With a need for a larger armamentarium of therapeutic options for those suffering from moderate-to-severe ulcerative colitis, vedolizumab, an α4β7-integrin biologic therapy, has recently received approval in the United States, Canada and Europe. However, it is unclear where it should be positioned in relation to current therapies for moderate-to-severe ulcerative colitis. Areas covered: We systematically reviewed the literature for phase 1, phase 2 and phase 3 randomized controlled trials assessing the role of vedolizumab in ulcerative colitis. Expert opinion: Trials assessing vedolizumab highlight its arrival as an effective and safe therapy for patients suffering from ulcerative colitis.

Will computer-aided detection and diagnosis revolutionize colonoscopy?

71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 Ca critical health concern and a significant financial burden, not only in North America, but worldwide. This highlights the importance of colonoscopy as a cost-effective means of preventing CRC through the identification and removal of polyps. However, colonoscopy is operator dependent. Variability in the skill and diligence of the endoscopist to detect and remove polyps impacts the ability of colonoscopy to reduce the risk of interval CRC and its associated mortality. Moreover, the use of colonoscopy itself carries its own economic footprint, specifically, the associated costs of removing and histologically evaluating all identified polyps regardless of their malignant potential. With the above point in mind, efforts have been made to improve the adenoma detection rate (ADR) through various strategies, including the use of highdefinition endoscopes and cap attachments. Furthermore, enhanced imaging modalities have been developed as a means of performing an “optical biopsy,” thereby empowering the endoscopist to resect and discard diminutive adenomas without pathology review or to leave diminutive distal hyperplastic polyps in situ. Unfortunately, these interventions have their limitations, specifically outside the hands of expert endoscopists. Therefore, a need exists for further technical advancements to optimize both the detection of polyps and their endoscopic evaluation. Computer-aided detection (CADe) and computer-aided diagnosis (CADx) are systems that incorporate a computer’s ability to learn and perform specific tasks. Through advances in machine learning and deep learning methodology, computers can now learn and perform specific endoscopic tasks that previously were the responsibility _____________________________________