Statistical considerations for cardiovascular clinical trials straddling the continuum of pandemic phases.

In 2020, the NIH and FDA issued guidance documents that laid the foundation for human subject research during an unprecedented pandemic. To bridge these general considerations to actual applications in cardiovascular interventional device trials, the PAndemic Impact on INTErventional device ReSearch (PAIINTERS) Working Group was formed in early 2021 under the Predictable And Sustainable Implementation Of National CardioVascular Registries (PASSION CV Registries). The PAIINTER's Part I report, published by Rymer et al. [5], provided a comprehensive overview of the operational impact on interventional studies during the first year of the Pandemic. PAIINTERS Part II focused on potential statistical issues related to bias, variability, missing data, and study power when interventional studies may start and end in different pandemic phases. Importantly, the paper also offers practical mitigation strategies to adjust or minimize the impact for both SATs and RCTs, providing a valuable resource for researchers and professionals involved in cardiovascular clinical trials.

Using Separate Single-Outcome Risk Presentations Instead of Integrated Multioutcome Formats Improves Comprehension in Discrete Choice Experiments.

INTRODUCTION: Despite decades of research on risk-communication approaches, questions remain about the optimal methods for conveying risks for different outcomes across multiple time points, which can be necessary in applications such as discrete choice experiments (DCEs). We sought to compare the effects of 3 design factors: 1) separated versus integrated presentations of the risks for different outcomes, 2) use or omission of icon arrays, and 3) vertical versus horizontal orientation of the time dimension. METHODS: We conducted a randomized study among a demographically diverse sample of 2,242 US adults recruited from an online panel (mean age 59.8 y, s = 10.4 y; 21.9% African American) that compared risk-communication approaches that varied in the 3 factors noted above. The primary outcome was the number of correct responses to 12 multiple-choice questions asking survey respondents to identify specific numbers, contrast options to recognize dominance (larger v. smaller risks), and compute differences. We used linear regression to test the effects of the 3 design factors, controlling for health literacy, graph literacy, and numeracy. We also measured choice consistency in a subsequent DCE choice module. RESULTS: Mean comprehension varied significantly across versions (P < 0.001), with higher comprehension in the 3 versions that provided separated risk information for each risk. In the multivariable regression, separated risk presentation was associated with 0.58 more correct responses (P < 0.001; 95% confidence interval: 0.39, 0.77) compared with integrated risk information. Neither providing icon arrays nor using vertical versus horizontal time formats affected comprehension rates, although participant understanding did correlate with DCE choice consistency. CONCLUSIONS: In presentations of multiple risks over multiple time points, presenting risk information separately for each health outcome appears to increase understanding. HIGHLIGHTS: When conveying information about risks of different outcomes at multiple time points, separate presentations of single-outcome risks resulted in higher comprehension than presentations that combined risk information for different outcomes.We also observed benefits of presenting single-outcome risks separately among respondents with lower numeracy and graph literacy.Study participants who scored higher on risk understanding were more internally consistent in their responses to a discrete choice experiment.

The medical device development ecosystem: Current regulatory state and challenges for future development: A review.

BACKGROUND/PURPOSE: There has been increasing emphasis on the development of new technology to mitigate unmet clinical needs in cardiovascular disease. This emphasis results in part from recognition that many devices, although being initially developed in the United States, were studied, and then eventually approved abroad before being returned to the U.S. for clinical application. The FDA (Food and Drug Administration) guidance document on Early Feasibility Studies (EFS) and then the 21st Century Cures Act from 2013 to 2016 focused on these issues. MATERIALS/METHODS: There are multiple components of medical device translational pathways to be considered in continuing to reach the goal of providing early access to safe and effective products to the U.S. POPULATION: This review article documents the various stages from early idea innovation to device design and iteration to clinical testing and then potential approval and application in the wide clinical practice of cardiovascular health care. RESULTS: The CDRH (Centers for Devices and Radiological Health) has focused on key components including EFS, Breakthrough Devices Program, Total Product Life Cycle, the Unique Device Identification Program, the establishment of a Digital Health Center of Excellence, and leveraging Collaborative Communities. Each of these initiatives focuses on improving the Medical Device Development Ecosystem. CONCLUSIONS: Major changes in device translational research have improved the device research climate in the United States. Goals remain including increased training and education for constituencies aspiring to work in the field of device development and regulation as part of a continuous health care learning system.

Standardized Definitions for Cardiogenic Shock Research and Mechanical Circulatory Support Devices: Scientific Expert Panel From the Shock Academic Research Consortium (SHARC).

The Shock Academic Research Consortium is a multi-stakeholder group, including representatives from the US Food and Drug Administration and other government agencies, industry, and payers, convened to develop pragmatic consensus definitions useful for the evaluation of clinical trials enrolling patients with cardiogenic shock, including trials evaluating mechanical circulatory support devices. Several in-person and virtual meetings were convened between 2020 and 2022 to discuss the need for developing the standardized definitions required for evaluation of mechanical circulatory support devices in clinical trials for cardiogenic shock patients. The expert panel identified key concepts and topics by performing literature reviews, including previous clinical trials, while recognizing current challenges and the need to advance evidence-based practice and statistical analysis to support future clinical trials. For each category, a lead (primary) author was assigned to perform a literature search and draft a proposed definition, which was presented to the subgroup. These definitions were further modified after feedback from the expert panel meetings until a consensus was reached. This manuscript summarizes the expert panel recommendations focused on outcome definitions, including efficacy and safety.

Consensus minimum core data elements adapted to peripheral vascular intervention in the drug-eluting era: Consensus report from the Registry Assessment of Peripheral Interventional Devices (RAPID) Pathways "LEAN" working group.

Registry Assessment of Peripheral Interventional Devices (RAPID) initiated the Pathways Program to provide a transparent, collaborative forum in which to pursue insights into multiple unresolved questions on benefit-risk of paclitaxel-coated devices, including understanding the basis of the mortality signal, without a demonstrable potential biological mechanism, and whether the late mortality signal could be artifact intrinsic to multiple independent prospective randomized data sources that did not prespecify death as a long-term end point. In response to the directive, the LEAN-Case Report Form working group focused on enhancements to the RAPID Phase I Minimum Core Data set through the addition of key clinical modifiers that would be more strongly linked to longer-term mortality outcomes after peripheral arterial disease intervention in the drug-eluting device era, with the goal to have future mortality signals more accurately examined.

Defining Strategies of Modulation of Antiplatelet Therapy in Patients With Coronary Artery Disease: A Consensus Document from the Academic Research Consortium.

Antiplatelet therapy is the mainstay of pharmacologic treatment to prevent thrombotic or ischemic events in patients with coronary artery disease treated with percutaneous coronary intervention and those treated medically for an acute coronary syndrome. The use of antiplatelet therapy comes at the expense of an increased risk of bleeding complications. Defining the optimal intensity of platelet inhibition according to the clinical presentation of atherosclerotic cardiovascular disease and individual patient factors is a clinical challenge. Modulation of antiplatelet therapy is a medical action that is frequently performed to balance the risk of thrombotic or ischemic events and the risk of bleeding. This aim may be achieved by reducing (ie, de-escalation) or increasing (ie, escalation) the intensity of platelet inhibition by changing the type, dose, or number of antiplatelet drugs. Because de-escalation or escalation can be achieved in different ways, with a number of emerging approaches, confusion arises with terminologies that are often used interchangeably. To address this issue, this Academic Research Consortium collaboration provides an overview and definitions of different strategies of antiplatelet therapy modulation for patients with coronary artery disease, including but not limited to those undergoing percutaneous coronary intervention, and consensus statements on standardized definitions.

Comparative Effectiveness of Percutaneous Microaxial Left Ventricular Assist Device vs Intra-Aortic Balloon Pump or No Mechanical Circulatory Support in Patients With Cardiogenic Shock.

Importance: Recent studies have produced inconsistent findings regarding the outcomes of the percutaneous microaxial left ventricular assist device (LVAD) during acute myocardial infarction with cardiogenic shock (AMICS). Objective: To compare the percutaneous microaxial LVAD vs alternative treatments among patients presenting with AMICS using observational analyses of administrative data. Design, Setting, and Participants: This comparative effectiveness research study used Medicare fee-for-service claims of patients admitted with AMICS undergoing percutaneous coronary intervention from October 1, 2015, through December 31, 2019. Treatment strategies were compared using (1) inverse probability of treatment weighting to estimate the effect of different baseline treatments in the overall population; (2) instrumental variable analysis to determine the effectiveness of the percutaneous microaxial LVAD among patients whose treatment was influenced by cross-sectional institutional practice patterns; (3) an instrumented difference-in-differences analysis to determine the effectiveness of treatment among patients whose treatment was influenced by longitudinal changes in institutional practice patterns; and (4) a grace period approach to determine the effectiveness of initiating the percutaneous microaxial LVAD within 2 days of percutaneous coronary intervention. Analysis took place between March 2021 and December 2022. Interventions: Percutaneous microaxial LVAD vs alternative treatments (including medical therapy and intra-aortic balloon pump). Main Outcomes and Measures: Thirty-day all-cause mortality and readmissions. Results: Of 23 478 patients, 14 264 (60.8%) were male and the mean (SD) age was 73.9 (9.8) years. In the inverse probability of treatment weighting analysis and grace period approaches, treatment with percutaneous microaxial LVAD was associated with a higher risk-adjusted 30-day mortality (risk difference, 14.9%; 95% CI, 12.9%-17.0%). However, patients receiving the percutaneous microaxial LVAD had a higher frequency of factors associated with severe illness, suggesting possible confounding by measures of illness severity not available in the data. In the instrumental variable analysis, 30-day mortality was also higher with percutaneous microaxial LVAD, but patient and hospital characteristics differed across levels of the instrumental variable, suggesting possible confounding by unmeasured variables (risk difference, 13.5%; 95% CI, 3.9%-23.2%). In the instrumented difference-in-differences analysis, the association between the percutaneous microaxial LVAD and mortality was imprecise, and differences in trends in characteristics between hospitals with different percutaneous microaxial LVAD use suggested potential assumption violations. Conclusions: In observational analyses comparing the percutaneous microaxial LVAD to alternative treatments among patients with AMICS, the percutaneous microaxial LVAD was associated with worse outcomes in some analyses, while in other analyses, the association was too imprecise to draw meaningful conclusions. However, the distribution of patient and institutional characteristics between treatment groups or groups defined by institutional differences in treatment use, including changes in use over time, combined with clinical knowledge of illness severity factors not captured in the data, suggested violations of key assumptions that are needed for valid causal inference with different observational analyses. Randomized clinical trials of mechanical support devices will allow valid comparisons across candidate treatment strategies and help resolve ongoing controversies.

Comparison of Unibody and Non-Unibody Endografts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries: The SAFE-AAA Study.

BACKGROUND: Concerns have been raised about the long-term performance of aortic stent grafts for the treatment of abdominal aortic aneurysms, in particular, unibody stent grafts (eg, Endologix AFX AAA stent grafts). Only limited data sets are available to evaluate the long-term risks related to these devices. The SAFE-AAA Study (Comparison of Unibody and Non-Unibody Endografts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries Study) was designed with the Food and Drug Administration to provide a longitudinal assessment of the safety of unibody aortic stent grafts among Medicare beneficiaries. METHODS: The SAFE-AAA Study was a prespecified, retrospective cohort study evaluating whether unibody aortic stent grafts are noninferior to non-unibody aortic stent grafts with respect to the composite primary outcome of aortic reintervention, rupture, and mortality. Procedures were evaluated from August 1, 2011, through December 31, 2017. The primary end point was evaluated through December 31, 2019. Inverse probability weighting was used to account for imbalances in observed characteristics. Sensitivity analyses were used to evaluate the effect of unmeasured confounding, including assessment of the falsification end points heart failure, stroke, and pneumonia. A prespecified subgroup included patients treated from February 22, 2016, through December 31, 2017, corresponding to the market release of the most contemporary unibody aortic stent grafts (Endologix AFX2 AAA stent graft). RESULTS: Of 87 163 patients who underwent aortic stent grafting at 2146 US hospitals, 11 903 (13.7%) received a unibody device. The average age of the total cohort was 77.0±6.7 years, 21.1% were female, 93.5% were White, 90.8% had hypertension, and 35.8% used tobacco. The primary end point occurred in 73.4% of unibody device-treated patients versus 65.0% of non-unibody device-treated patients (hazard ratio, 1.19 [95% CI, 1.15-1.22]; noninferior P value of 1.00; median follow-up, 3.4 years). Falsification end points were negligibly different between groups. In the subgroup treated with contemporary unibody aortic stent grafts, the cumulative incidence of the primary end point occurred in 37.5% of unibody device-treated patients and 32.7% of non-unibody device-treated patients (hazard ratio, 1.06 [95% CI, 0.98-1.14]). CONCLUSIONS: In the SAFE-AAA Study, unibody aortic stent grafts failed to meet noninferiority compared with non-unibody aortic stent grafts with respect to aortic reintervention, rupture, and mortality. These data support the urgency of instituting a prospective longitudinal surveillance program for monitoring safety events related to aortic stent grafts.

Early feasibility studies in the United States: Focus on electrophysiology.

The care of patients with heart rhythm disorders is often dependent on technologies developed to address their unique clinical needs. Although much innovation occurs in the United States, recent decades have seen a significant proportion of early clinical studies performed outside the United States, driven largely by costly and time-inefficient processes seemingly inherent to the United States research ecosystem. As a result, the goals of early patient access to novel devices to address unmet needs and efficient technology development in the United States remain incompletely realized. This review will introduce key aspects of this discussion, organized by the Medical Device Innovation Consortium, in an effort to broaden awareness and encourage engagement by stakeholders in an effort to address central issues and therefore further a growing effort to shift Early Feasibility Studies to the United States for the benefit of all involved.

Development and validation of an automated algorithm for end point adjudication for a large U.S. national registry.

BACKGROUND: Clinical events committee (CEC) evaluation is the standard approach for end point adjudication in clinical trials. Due to resource constraints, large registries typically rely on site-reported end points without further confirmation, which may preclude use for regulatory oversight. METHODS: We developed a novel automated adjudication algorithm (AAA) for end point adjudication in the National Cardiovascular Data Registry Left Atrial Appendage Occlusion (LAAO) Registry using an iterative process using CEC adjudication as the "gold standard." A ≥80% agreement rate between automated algorithm adjudication and CEC adjudication was prespecified as clinically acceptable. Agreement rates were calculated. RESULTS: A total of 92 in-hospital and 127 post-discharge end points were evaluated between January 1, 2016 and June 30, 2019 using AAA and CEC. Agreement for neurologic events was >90%. Percent agreement for in-hospital and post-discharge events was as follows: ischemic stroke 95.7% and 94.5%, hemorrhagic stroke 97.8% and 96.1%, undetermined stroke 97.8% and 99.2%, transient ischemic attack 98.9% and 98.4% and intracranial hemorrhage 100.0% and 94.5%. Agreement was >80% for major bleeding (83.7% and 90.6%) and major vascular complication (89.1% and 97.6%). With this approach, <1% of site reported end points require CEC adjudication. Agreement remained very good during the period after algorithm derivation. CONCLUSIONS: An AAA-guided approach for end point adjudication was successfully developed and validated for the LAAO Registry. With this approach, the need for formal CEC adjudication was substantially reduced, with accuracy maintained above an 80% agreement threshold. After application specific validation, these methods could be applied to large registries and clinical trials to reduce the cost of event adjudication while preserving scientific validity.

One-Year Follow-Up of Vascular Intervention Trials Disrupted by the COVID-19 Pandemic: A Use-Case landscape.

INTRODUCTION: The COVID-19 pandemic had an unprecedented impact on cardiovascular clinical research. The decision-making and state of study operations in cardiovascular trials 1-year after interruption has not been previously described. METHODS: In the spring of 2020, we created a pandemic impact task force to develop a landscape of use case scenarios from 17 device trials of peripheral artery disease (PAD) and coronary artery disease (CAD) interventions. In conjunction with publicly available (clinictrials.gov) study inclusion criteria, primary endpoints and study design, information was shared for this use-case landscape by trial leadership and data owners. RESULTS: A total of 17 actively enrolling trials (9 CAD and 8 PAD) volunteered to populate the use case landscape. All 17 were multicenter studies (12 in North America and 5 international). Fifteen studies were industry-sponsored, of which 13 were FDA approved IDEs, one was PCORI-sponsored and two were sponsored by the NIH. Enrollment targets ranged from 150 to 9000 pts. At the time of interruption, 5 trials were <20 % enrolled, 9 trials were 50-80 % enrolled and 3 trials were >80 % enrolled. At 1 year, the majority of studies were continuing to enroll in the context of more sporadic but ongoing pandemic activity. CONCLUSIONS: At 1 year from the first surge interruptions, most trials had resumed enrollment. Trials most heavily interrupted were trials early in enrollment and those trials not able to pivot to virtual patient and site visits. Further work is needed to determine the overall impact on vascular intervention trials disrupted during the COVID-19 pandemic.

US FDA best practices for initiating early feasibility studies for neurological devices in the United States.

This article describes the efforts of the US Food and Drug Administration (FDA) Office of Neurological and Physical Medicine Devices to facilitate early clinical testing of potentially beneficial neurological devices in the US. Over the past 5 years, the FDA has made significant advances to this aim by developing early feasibility study best practices and encouraging developers and innovators to initiate their clinical studies in the US. The FDA uses several regulatory approaches to help start neurological device clinical studies, such as early engagement with sponsors and developers, in-depth interaction during the FDA review phase of a regulatory submission, and provision of an FDA toolkit that reviewers can apply to the most challenging submissions.

Definitions and Clinical Trial Design Principles for Coronary Artery Chronic Total Occlusion Therapies: CTO-ARC Consensus Recommendations.

Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence.

Important considerations for trials for peripheral arterial disease: Lessons learned from the paclitaxel mortality signal: A report on behalf of the registry assessment for peripheral interventional Devices (RAPID) Paclitaxel Pathways Program.

The Registry Assessment of Peripheral Devices (RAPID) convened a multidisciplinary group of stakeholders including clinicians, academicians, regulators and industry representatives to conduct an in-depth review of limitations associated with the data available to assess the paclitaxel mortality signal. Available studies were evaluated to identify strengths and limitations in the study design and data quality, which were translated to lessons learned to help guide the design, execution, and analyses of future studies. We suggest numerous actionable responses, such as the development and use of harmonized data points and outcomes in a consensus lean case report form. We advocate for reduction in missing data and efficient means for accrual of larger sample sizes in Peripheral arterial disease studies or use of supplemental datasets. Efforts to share lessons learned and working collaboratively to address such issues may improve future data in this device area and ultimately benefit patients. Condensed Abstract: Data sources evaluating paclitaxel-coated devices were evaluated to identify strengths and limitations in the study design and data quality, which were translated to lessons learned to help guide the design, execution, and analyses of future studies. We suggest numerous actionable responses, which we believe may improve future data in this device area and ultimately benefit patients.

Early Feasibility Studies for Cardiovascular Devices in the United States: JACC State-of-the-Art Review.

The development of technology to treat unmet clinical patient needs in the United States has been an important focus for the U.S. Food and Drug Administration and the 2016 Congressional 21st Century Cures Act. In response, a program of early feasibility studies (EFS) has been developed. One of the important issues has been the outmigration of the development and testing of medical devices from the United States. The EFS committee has developed and implemented processes to address issues to develop strategies for early treatment of these patient groups. Initial implementation of the U.S. Food and Drug Administration EFS program has been successful, but residual significant problems have hindered the opportunity to take full advantage of the program. These include delays in gaining Institutional Review Board approval, timeliness of budget and contractual negotiations, and lack of access to and enrollment of study subjects. This paper reviews improvements that have been made to the U.S. EFS ecosystem and outlines potential approaches to address remaining impediments to program success.