Sex-specific, high-sensitivity cardiac troponin T cut-off concentrations for ruling out acute myocardial infarction with a single measurement.

OBJECTIVE: Sex-specific diagnostic cut-offs may improve the test characteristics of high-sensitivity troponin assays for the diagnosis of myocardial infarction (MI). The objective of this study was to quantify test characteristics of sex-specific cut-offs of a single, high-sensitivity cardiac troponin T (hs-cTnT) assay for 7-day MI in patients with chest pain. METHODS: This observational cohort study included consecutive emergency department (ED) patients with suspected cardiac chest pain from four Canadian EDs who had an hs-cTnT assay performed within 60 minutes of ED arrival. The primary outcome was MI at 7 days. We quantified test characteristics (sensitivity, negative predictive value [NPV], likelihood ratios and proportion of patients ruled out) for multiple combinations of sex-specific, rule-out cut-offs. We calculated the net reclassification index compared to universal rule-out cut-offs. RESULTS: In 7,130 patients (3,931 men and 3,199 women), the 7-day MI incidence was 7.38% among men and 3.78% among women. Optimal sex-specific cut-offs (<8 ng/L for men and <7 ng/L for women) had a 98.5% sensitivity for MI and ruled out MI in 55.8% of patients. This would enable an absolute increase in the proportion of patients who were able to be ruled out with a single hs-cTnT of 13.2% to 22.2%, depending on the universal rule-out concentration used as a comparator. CONCLUSIONS: Sex-specific hs-cTnT cut-offs for ruling out MI at ED arrival may improve classification performance, enabling more patients to be safely ruled out at ED arrival. However, differences between sex-specific and universal cut-off concentrations are within the variation of the assay, limiting the clinical utility of this approach. These findings should be confirmed in other data sets.

Personal social networks and organizational affiliation of South Asians in the United States.

BACKGROUND: Understanding the social lives of South Asian immigrants in the United States (U.S) and their influence on health can inform interpersonal and community-level health interventions for this growing community. This paper describe the rationale, survey design, measurement, and network properties of 700 South Asian individuals in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) social networks ancillary study. METHODS: MASALA is a community-based cohort, established in 2010, to understand risk factors for cardiovascular disease among South Asians living in the U.S. Survey data collection on personal social networks occurred between 2014 and 2017. Network measurements included size, composition, density, and organizational affiliations. Data on participants' self-rated health and social support functions and health-related discussions among network members were also collected. RESULTS: Participants' age ranged from 44 to 84 (average 59 years), and 57% were men. South Asians had large (size=5.6, SD=2.6), kin-centered (proportion kin=0.71, SD=0.28), and dense networks. Affiliation with religious and spiritual organizations was perceived as beneficial to health. Emotional closeness with network members was positively associated with participants' self-rated health (p-value <0.001), and networks with higher density and more kin were significantly associated with health-related discussions. DISCUSSION: The MASALA networks study advances research on the cultural patterning of social relationships and sources of social support in South Asians living in the U.S. Future analyses will examine how personal social networks and organizational affiliations influence South Asians' health behaviors and outcomes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02268513.

Expanding the impact of a longstanding Canadian cardiac registry through data linkage: challenges and opportunities.

The Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) began as a province-wide inception cohort of all adult Alberta residents undergoing cardiac catheterization for ischemic heart disease. Strengths of the APPROACH initiative include the prospective collection of detailed clinical, procedural, and treatment information, measured at point-of-care. While this aspect of APPROACH provides data users with several advantages over use of typical administrative data, the ability to link APPROACH with data from multiple other sources has provided several unique opportunities to measure cardiovascular care and outcomes. As of June 2018, clinical information has been collected by APPROACH on over 240,000 adult Alberta residents. Linkage of this rich clinical data to administrative health data (eg. Vital statistics, hospitalizations, ambulatory events, prescription medications), secondary use clinical data (e.g. laboratory, ECG, rehabilitation, EMR, imaging) and other data sources (eg. Geospatial, crime data, meteorological) allows better study of the determinants of a patient's health trajectory. This paper describes applied examples of work that has leveraged the potential of linking several datasets with the APPROACH registry.

Comparative Evaluation of 2-Hour Rapid Diagnostic Algorithms for Acute Myocardial Infarction Using High-Sensitivity Cardiac Troponin T.

BACKGROUND: Symptoms of acute coronary syndrome account for a large proportion of emergency department (ED) visits and hospitalizations. High-sensitivity troponin can rapidly rule out or rule in acute myocardial infarction (AMI) within a short time of ED arrival. We sought to validate test characteristics and classification performance of 2-hour high-sensitivity troponin T (hsTnT) algorithms for the rapid diagnosis of AMI. METHODS: We included consecutive patients from 4 academic EDs with suspected cardiac chest pain who had hsTnT assays performed 2 hours apart (± 30 minutes) as part of routine care. The primary outcome was AMI at 7 days. Secondary outcomes included major adverse cardiac events (mortality, AMI, and revascularization). Test characteristics and classification performance for multiple 2-hour algorithms were quantified. RESULTS: Seven hundred twenty-two patients met inclusion criteria. Seven-day AMI incidence was 10.9% and major adverse cardiac event incidence was 13.7%. A 2-hour rule-out algorithm proposed by Reichlin and colleagues ruled out AMI in 59.4% of patients with 98.7% sensitivity and 99.8% negative predictive value (NPV). The 2-hour rule-out algorithm proposed by the United Kingdom National Institute for Health and Care Excellence ruled out AMI in 50.3% of patients with similar sensitivity and NPV. Other exploratory algorithms had similar sensitivity but marginally better classification performance. According to Reichlin et al., the 2-hour rule-in algorithm ruled in AMI in 16.5% of patients with 92.4% specificity and 58.5% positive predictive value. CONCLUSIONS: Two-hour hsTnT algorithms can rule out AMI with very high sensitivity and NPV. The algorithm developed by Reichlin et al. had superior classification performance. Reichlin and colleagues' 2-hour rule-in algorithm had poor positive predictive value and might not be suitable for early rule-in decision-making.

Undetectable Concentrations of a Food and Drug Administration-approved High-sensitivity Cardiac Troponin T Assay to Rule Out Acute Myocardial Infarction at Emergency Department Arrival.

BACKGROUND: The objective of this study was to quantify the sensitivity of very low concentrations of high-sensitivity cardiac troponin T (hsTnT) at ED arrival for acute myocardial infarction (AMI) in a large cohort of chest pain patients evaluated in real-world clinical practice. METHODS: This retrospective study included consecutive ED patients with suspected cardiac chest pain evaluated in four urban EDs, excluding those with ST-elevation AMI, cardiac arrest or abnormal kidney function. The primary outcomes were AMI at 7, 30, and 90 days. Secondary outcomes included major adverse cardiac events (MACE; all-cause mortality, AMI, and revascularization) and the individual MACE components. Test characteristics were calculated for hsTnT values from 3 to 200 ng/L . RESULTS: A total of 7,130 patients met inclusion criteria. AMI incidences at 7, 30, and 90 days were 5.8, 6.0, and 6.2%. When the hsTnT assay was performed at ED arrival, the limit of blank of the assay (3 ng/L) ruled out 7-day AMI in 15.5% of patients with 100% sensitivity and negative predictive value (NPV). The limit of detection of the assay (5 ng/L) ruled out AMI in 33.6% of patients with 99.8% sensitivity and 99.95% NPV for 7-day AMI. The limit of quantification (the Food and Drug Administration [FDA]-approved cutoff for lower the reportable limit) of 6 ng/L ruled out AMI in 42.2% of patients with 99.8% sensitivity and 99.95% NPV. The sensitivities of the cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.6, 97.4, and 96.6%, respectively. The NPVs of the cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.8, 99.5, and 99.4%, respectively. A secondary analysis was performed in a subgroup of 3,549 higher-risk patients who underwent serial troponin testing. In this subgroup, a cutoff of 3 ng/L ruled out 7-day AMI in 9.6% of patients with 100% sensitivity and NPV, a cutoff of 5 ng/L ruled out 7-day AMI in 23.3% of patients with 99.7% sensitivity and 99.9% NPV, and a cutoff of 6 ng/L ruled out 7-day AMI in 29.8% of patients with 99.7 and 99.9% NPV. In the higher-risk subgroup, the sensitivities of cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.8, 97.4, and 96.6%, respectively. In this higher-risk subgroup, the NPV of cutoffs of <3, <5, and <6 ng/L for 7-day MACE were 99.7, 98.5, and 98.4%, respectively. CONCLUSIONS: When used in real-world clinical practice conditions, hsTnT concentrations < 6 ng/L (below the lower reportable limit for an FDA-approved assay) at the time of ED arrival can rule out AMI with very high sensitivity and NPV. The sensitivity for MACE is unacceptably low, and thus a single-troponin rule-out strategy should only be used in the context of a structured risk evaluation.

Current usage and future trends in gross digital photography in Canada.

BACKGROUND: The purpose of this study was to assess the current usage, utilization and future direction of digital photography of gross surgical specimens in pathology laboratories across Canada. METHODS: An online survey consisting of 23 multiple choice and free-text questions regarding gross digital photography was sent out to via email to laboratory staff across Canada involved in gross dissection of surgical specimens. RESULTS: Sixty surveys were returned with representation from most of the provinces. Results showed that gross digital photography is utilized at most institutions (90.0%) and the primary users of the technology are Pathologists (88.0%), Pathologists' Assistants (54.0%) and Pathology residents (50.0%). Most respondents felt that there is a definite need for routine digital imaging of gross surgical specimens in their practice (80.0%). The top two applications for gross digital photography are for documentation of interesting/ complex cases (98.0%) and for teaching purposes (84.0%). The main limitations identified by the survey group are storage space (42.5%) and security issues (40.0%). Respondents indicated that future applications of gross digital photography mostly include teaching (96.6%), presentation at tumour boards/ clinical rounds (89.8%), medico-legal documentation (72.9%) and usage for consultation purposes (69.5%). CONCLUSIONS: The results of this survey indicate that pathology staff across Canada currently utilizes gross digital images for regular documentation and educational reasons. They also show that the technology will be needed for future applications in teaching, consultation and medico-legal purposes.