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Abstract Background Cardiovascular disease (CVD) is the leading cause of death globally for both men and women, yet women remain historically underrepresented in cardiovascular clinical trials (CV trials), despite facing a disproportionately high burden of morbidity and mortality in many forms of CVD. Purpose We aim to determine the representation of women across a broad range of CV trials. Methods The participation of women in CV trials registered on ClinicalTrials.gov from 2017 to 2023 was systematically determined through the extraction of publicly available information. Data was extracted to identify the country of study, disease type, trial size, clinical intervention and age of the participants. We calculated the proportion of women and the ratio of number of females to male participants (F:M ratio) for each trial. The female participation to prevalence ratio (PPR) was estimated for each trial based on the relative prevalence of the disease by sex in the specified region. Results We identified 1,079 registered CV trials, which included 1,396,104 participants, of whom 571,641 (41.0%) were women. The median F:M ratio was significantly lower for studies on arrhythmia (0.5), coronary heart disease (CHD) (0.39), acute coronary syndrome (ACS) (0.32) and heart failure (HF) (0.51), but was higher for obesity (1.44) and pulmonary hypertension (PH) (2.86) CV trials. F:M ratio was higher for trials on lifestyle intervention (1.51) than for drug trials. PPRs were low for clinical trials on CHD (0.66), ACS (0.79), and stroke (0.74). There was a trend to increasing PPR from 2017 to 2023, p=0.056. Conclusion Representation of women in CV trials varies by disease state, region, intervention, and sponsor type. Better understanding of reasons for these differences may enable more tailored interventions to improve representation of women globally and across therapeutic areas.Figure 1 Figure 2

Abstract In comparative effectiveness research (CER), ensuring internal, construct, and external validity is crucial. Internal validity determines whether observed outcomes are causally linked to an intervention; construct validity assesses whether a study measures what it intends to; and external validity relates to generalizability in routine practice. Double-blind randomized trials optimize internal validity by minimizing bias and confounding, while construct validity is strengthened through pre-specified protocols and standardized data collection. However, controlled conditions limit external validity. Pragmatic RCTs improve generalizability but may compromise internal validity due to open-label designs. Observational CER studies—including observational studies following the target trial emulation framework—offer broader external validity and feasibility in less time and at lower cost. However, due to lack of random assignment, these studies are susceptible to measured and unmeasured confounding. Several techniques help mitigate these concerns, including a detailed pre-specified protocol, tools such as propensity score matching to balance measured confounders, falsification endpoint testing for assessing the presence of unmeasured confounders, and quasi-experimental designs (including instrumental variable analysis), which may be able to address both. Pre-specified sensitivity analyses and triangulation with complementary data sources further enhance robustness. Construct validity in observational CER depends on accurate patient profiling and validated computational phenotypes for identifying patients, exposures, and outcomes. Thoughtful study design and analytic rigor are essential for balancing these validity considerations. This brief review highlights these issues with examples from thrombosis research.

Abstract Background Cardiac troponin is the gold-standard biomarker for the evaluation of patients with suspected acute myocardial infarction (MI). Improvements in assay technology have led to high-sensitivity cardiac troponin assays that, when incorporated into accelerated diagnostic pathways, may rapidly diagnose or exclude acute MI more efficiently than conventional troponin assays. Content In this narrative review, we provide practical suggestions for implementing high-sensitivity cardiac troponin assays, review accelerated diagnostic pathways incorporating these assays, and review the impact of these assays on resource utilization and cost-effectiveness in relation to the evaluation of individuals with possible acute MI. Summary An increasing number of hospitals are transitioning to high-sensitivity cardiac troponin assays. This narrative review provides an overview of the potential benefits of this transition.

Introduction: Insulin-like growth factor-binding protein 7 (IGFBP7) was previously found to be associated with diastolic function in heart failure (HF) with reduced ejection fraction (EF), but it is unclear whether such associations exist in HF with preserved EF (HFpEF), where diastolic function is of pivotal importance. Hypotheses: Baseline (BL) and change (Δ) in IGFBP7 will be significantly associated and correlated with BL and Δ in diastolic indices as well as peak oxygen consumption (VO2 max ) in patients with HFpEF. IGFBP7 will decrease with sildenafil therapy. Methods: At BL and 6 months (6M), IGFBP7, imaging studies, and VO2 max were obtained and compared in 160 HFpEF patients randomized to sildenafil or placebo. Results: Patients with supramedian BL IGFBP7 concentrations (>219 ng/mL) were more likely to be older, to have more congestion and worse renal function, and to have elevated concentrations of several emerging or established HF biomarkers including amino-terminal pro-B-type natriuretic peptide, cystatin C, and highly sensitive troponin (all P<0.05). Higher BL IGFBP7 was correlated with indices of worse diastolic function, including higher E velocity (ρ=0.395, P<0.001), E/e’ (ρ=0.398, P<0.001), left atrial volume index (ρ=0.386, P<0.001), right ventricular systolic pressure (RVSP; ρ=0.413, P<0.001), and transmitral E/A (ρ=0.258, P=0.006). IGFBP7 was also inversely correlated with aortic distensability (ρ= -0.301, P=0.02). There was no association or correlation with measures of systolic function. Notably, in analyses adjusted for respective baseline variables, ΔIGFBP7 was significantly correlated with Δ in E (ρ=0.114), E/A (ρ=0.225), E/e’ (ρ=0.174), and RVSP (ρ=0.282; all P<0.03). Elevated BL IGFBP7 was associated with lower BL VO2 max (13.2 versus 11.1 mL/min/kg; P<0.001) and ΔIGFBP7 was inversely correlated with ΔVO2 max (ρ=-0.19, P=0.01). Subjects receiving sildenafil had a decrease in IGFBP7 over 6M in contrast to placebo-treated patients (median ΔIGFBP7 -1.5 versus +13.6 ng/mL; P<0.001). Conclusions: In patients with HFpEF, concentrations of IGFBP7 have unique relationships with measures of diastolic dysfunction and VO2 max . Rise in IGFBP7 may reflect worsening diastology and deteriorating VO2 max .

Abstract Endpoint adjudication (EA) is a common feature of contemporary randomized controlled trials (RCTs) in cardiovascular medicine. Endpoint adjudication refers to a process wherein a group of expert reviewers, known as the clinical endpoint committee (CEC), verify potential endpoints identified by site investigators. Events that are determined by the CEC to meet pre-specified trial definitions are then utilized for analysis. The rationale behind the use of EA is that it may lessen the potential misclassification of clinical events, thereby reducing statistical noise and bias. However, it has been questioned whether this is universally true, especially given that EA significantly increases the time, effort, and resources required to conduct a trial. Herein, we compare the summary estimates obtained using adjudicated vs. non-adjudicated site designated endpoints in major cardiovascular RCTs in which both were reported. Based on these data, we lay out a framework to determine which trials may warrant EA and where it may be redundant. The value of EA is likely greater when cardiovascular trials have nuanced primary endpoints, endpoint definitions that align poorly with practice, sub-optimal data completeness, greater operator variability, and lack of blinding. EA may not be needed if the primary endpoint is all-cause death or all-cause hospitalization. In contrast, EA is likely merited for more nuanced endpoints such as myocardial infarction, bleeding, worsening heart failure as an outpatient, unstable angina, or transient ischaemic attack. A risk-based approach to adjudication can potentially allow compromise between costs and accuracy. This would involve adjudication of a small proportion of events, with further adjudication done if inconsistencies are detected.

Introduction: High-sensitivity cardiac troponin (hs-cTn) assays were first approved for use in the U.S. in 2017. They are the guideline preferred biomarker to evaluate patients with acute chest pain. Few data exist regarding implementation of hs-cTn assays in the U.S. Hypothesis: We hypothesize that use of hs-cTn assays has increased over time and that patients assessed with hs-cTn have a shorter length of stay (LOS) and similar use of cardiac testing. Methods: We examined trends in implementation of hs-cTn assays among participating hospitals in the NCDR Chest Pain MI Registry from 1/1/2019 through 9/30/2021. Excluding STEMI patients, associations between hs-cTn use, in-hospital diagnostic imaging, and patient outcomes were assessed using logistic or negative binomial regression models. Results: Among 550 participating hospitals with 251,000 patients in the registry, implementation of hs-cTn assays increased from 3.3% in Q1, 2019 to 32.6% in Q3, 2021 (P trend <0.0001; Figure ). Implementation was similar by hospital size, type, and geographic location. hs-cTn use was associated with more echocardiography among patients with NSTE-ACS (82% vs. 75%; aOR: 1.43, 95% CI, 1.19-1.73) but not in low-risk chest pain. hs-cTn use was associated with decreased odds of invasive coronary angiography in low-risk patients (3.7% vs. 4.5%; aOR: 0.73, 95% CI, 0.58-0.92) but similar use in NSTE-ACS. There was no association between hs-cTn use and non-invasive stress/CTCA testing. Among NSTE-ACS patients, hs-cTn use was not associated with PCI, CABG, or in-hospital mortality. Use of hs-cTn was associated with shorter LOS (47.6 hours vs. 48 hours; IRR: 0.96, 95% CI, 0.93-0.98). Conclusions: Although implementation of hs-cTn among U.S. hospitals is increasing, most U.S hospitals continue to use less-sensitive troponin assays. hs-cTn use was associated with shorter LOS overall, greater use of echocardiography in NSTE-ACS, and lower use of invasive angiograms in low-risk patients.

Abstract Clinical biomarker research is growing at a fast pace, particularly in the cardiovascular field, due to the demanding requirement to provide personalized precision medicine. The lack of a distinct molecular signature for each cardiovascular derangement results in a one-size-fits-all diagnostic and therapeutic approach, which may partially explain suboptimal outcomes in heterogeneous cardiovascular diseases (e.g., heart failure with preserved ejection fraction). A multidimensional approach using different biomarkers is quickly evolving, but it is necessary to consider pre-analytical variables, those to which a biological sample is subject before being analyzed, namely sample collection, handling, processing, and storage. Pre-analytical errors can induce systematic bias and imprecision, which may compromise research results, and are easy to avoid with an adequate study design. Academic clinicians and investigators must be aware of the basic considerations for biospecimen management and essential pre-analytical recommendations as lynchpin for biological material to provide efficient and valid data.