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.

Postmarketing Surveillance of Inferior Vena Cava Filters Among US Medicare Beneficiaries: The SAFE-IVC Study.

Importance: Inferior vena cava filters (IVCFs) are commonly used to prevent pulmonary embolism in selected clinical scenarios, despite limited evidence to support their use. Current recommendations from professional societies and the US Food and Drug Administration endorse timely IVCF retrieval when clinically feasible. Current IVCF treatment patterns and outcomes remain poorly described. Objectives: To evaluate temporal trends and practice patterns in IVCF insertion and retrieval among older US patients and report the incidence of periprocedural and long-term safety events of indwelling and retrieved IVCFs. Design, Setting, and Participants: Prespecified, retrospective, observational cohort of Medicare Fee-for-Service (FFS) beneficiaries, leveraging 100% of samples of inpatient and outpatient claims data from January 1, 2013, to December 31, 2021. Exposure: First-time IVCF insertion while insured by Medicare FFS. Main Outcomes and Measures: The primary safety outcome was the composite of all-cause death, filter-related complications (eg, fracture, embolization), operating room visits following filter-related procedures, or new diagnosis of deep vein thrombosis (DVT). Events were considered periprocedural if they occurred within 30 days of IVCF insertion or retrieval and long-term if they occurred more than 30 days after. Results: Among 270 866 patients with IVCFs placed during the study period (mean age, 75.1 years; 52.8% female), 64.9% were inserted for first-time venous thromboembolism (VTE), 26.3% for recurrent VTE, and 8.8% for VTE prophylaxis. Of these patients, 63.3% had major bleeds or trauma within 30 days of IVCF insertion. The volume of insertions decreased from 44 680 per year in 2013 to 19 501 per year in 2021. The cumulative incidence of retrieval was 15.3% at a median of 1.2 years and 16.8% at maximum follow-up of 9.0 years. Older age, more comorbidities, and Black race were associated with a decreased likelihood of retrieval, whereas placement at a large teaching hospital was associated with an increased likelihood of retrieval. The incidence of caval thrombosis and DVT among patients with nonretrieved IVCFs was 2.2% (95% CI, 2.1%-2.3%) and 9.2% (95% CI, 9.0%-9.3%), respectively. The majority (93.5%) of retrieval attempts were successful, with low incidence of 30-day complications (mortality, 0.7% [95% CI, 0.6%-0.8%]; filter-related complications, 1.4% [95% CI, 1.2%-1.5%]). Conclusions and Relevance: In this large, US real-world analysis, IVCF insertion declined, yet retrievals remained low. Strategies to increase timely retrieval are needed, as nonretrieved IVCFs may have long-term complications.

Standardized End Point Definitions for Coronary Intervention Trials: The Academic Research Consortium-2 Consensus Document.

The Academic Research Consortium (ARC)-2 initiative revisited the clinical and angiographic end point definitions in coronary device trials, proposed in 2007, to make them more suitable for use in clinical trials that include increasingly complex lesion and patient populations and incorporate novel devices such as bioresorbable vascular scaffolds. In addition, recommendations for the incorporation of patient-related outcomes in clinical trials are proposed. Academic Research Consortium-2 is a collaborative effort between academic research organizations in the United States and Europe, device manufacturers, and European, US, and Asian regulatory bodies. Several in-person meetings were held to discuss the changes that have occurred in the device landscape and in clinical trials and regulatory pathways in the last decade. The consensus-based end point definitions in this document are endorsed by the stakeholders of this document and strongly advocated for clinical trial purposes. This Academic Research Consortium-2 document provides further standardization of end point definitions for coronary device trials, incorporating advances in technology and knowledge. Their use will aid interpretation of trial outcomes and comparison among studies, thus facilitating the evaluation of the safety and effectiveness of these devices.

Standardized End Point Definitions for Coronary Intervention Trials: The Academic Research Consortium-2 Consensus Document.

The Academic Research Consortium (ARC)-2 initiative revisited the clinical and angiographic end point definitions in coronary device trials, proposed in 2007, to make them more suitable for use in clinical trials that include increasingly complex lesion and patient populations and incorporate novel devices such as bioresorbable vascular scaffolds. In addition, recommendations for the incorporation of patient-related outcomes in clinical trials are proposed. Academic Research Consortium-2 is a collaborative effort between academic research organizations in the United States and Europe, device manufacturers, and European, US, and Asian regulatory bodies. Several in-person meetings were held to discuss the changes that have occurred in the device landscape and in clinical trials and regulatory pathways in the last decade. The consensus-based end point definitions in this document are endorsed by the stakeholders of this document and strongly advocated for clinical trial purposes. This Academic Research Consortium-2 document provides further standardization of end point definitions for coronary device trials, incorporating advances in technology and knowledge. Their use will aid interpretation of trial outcomes and comparison among studies, thus facilitating the evaluation of the safety and effectiveness of these devices.

Utilizing national and international registries to enhance pre-market medical device regulatory evaluation.

Regulatory decisions are made based on the assessment of risk and benefit of medical devices at the time of pre-market approval and subsequently, when post-market risk-benefit balance needs reevaluation. Such assessments depend on scientific evidence obtained from pre-market studies, post-approval studies, post-market surveillance studies, patient perspective information, as well as other real world data such as national and international registries. Such registries provide real world evidence and are playing a more and more important role in enhancing the safety and effectiveness evaluation of medical devices. While these registries provide large quantities of data reflecting real world practice and can potentially reduce the cost of clinical trials, challenges arise concerning (1) data quality adequate for regulatory decision-making, (2) bias introduced at every stage and aspect of study, (3) scientific validity of study designs, and (4) reliability and interpretability of study results. This article will discuss related statistical and regulatory challenges and opportunities with examples encountered in medical device regulatory reviews.

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.

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.

An analysis of implantable cardiac device reliability. The case for improved postmarketing risk assessment and surveillance.

Implantable cardiac devices have become the mainstay of the treatment of patients with heart disease. However, data regarding their reliability and, inferentially, safety have been called into question. We reviewed annual reports submitted to the Food and Drug Administration Office of Device Evaluation by device manufacturers from 2003 to 2007. The annual number of implantable cardiac defibrillators (ICDs) and cardiac resynchronization therapy defibrillator (CRT-D) implants, explants, and returned devices were tabulated along with the cumulative (Cum) number of implants for each device. We derived an annual explantation rate (AER) defined as the ratio of the annual number of explants less the number of normal battery depletions/Cum (×1000). From 2003 to 2007, 256,392 CRT-D and 459,300 ICD devices were implanted in the United States. The overall mean (±SD) AERs for ICD and CRT-D devices were, respectively, 49.5 (15.6) per 1000 ICD devices and 82.6 (35.5) per 1000 CRT-D devices. The AER for each device type significantly decreased over the study period (P for trend <0.001) although the AER for CRT-D devices was 38% higher than that for ICD devices (P < 0.001). On average, 20.3% of CRT-D devices and 22.6% of ICD devices were returned to the manufacturer for analysis after explantation. The rates of explanted CRT-D and ICD devices decreased from 2003 to 2007. Notwithstanding this favorable trend, the AER for CRT-D devices was higher than that for ICD devices. Improved methods for tracking individual device histories are needed for more precise estimates of the risk of device explantation for suspected malfunction. The proportion of devices returned to the manufacturer is suboptimal and needs to be improved to better understand the mechanisms of device malfunction.

Bioprosthetic Aortic Valve Hemodynamics: Definitions, Outcomes, and Evidence Gaps: JACC State-of-the-Art Review.

A virtual workshop was organized by the Heart Valve Collaboratory to identify areas of expert consensus, areas of disagreement, and evidence gaps related to bioprosthetic aortic valve hemodynamics. Impaired functional performance of bioprosthetic aortic valve replacement is associated with adverse patient outcomes; however, this assessment is complicated by the lack of standardization for labelling, definitions, and measurement techniques, both after surgical and transcatheter valve replacement. Echocardiography remains the standard assessment methodology because of its ease of performance, widespread availability, ability to do serial measurements over time, and correlation with outcomes. Management of a high gradient after replacement requires integration of the patient's clinical status, physical examination, and multimodality imaging in addition to shared patient decisions regarding treatment options. Future priorities that are underway include efforts to standardize prosthesis sizing and labelling for both surgical and transcatheter valves as well as trials to characterize the consequences of adverse hemodynamics.

Interventional cardiology live case presentations: regulatory considerations.

Live case presentations are increasingly common at interventional cardiology conferences. Taking advantage of significant advances in communication technology, broadcasts of procedures can be viewed as an extension of traditional medical education targeted to large groups of practitioners. However, there are important ethical, commercial, and patient safety issues associated with live cases that deserve attention. Use of investigational devices in live case demonstrations is subject to review and approval by FDA's Center for Devices and Radiological Health (CDRH), and the outcomes of patients participating in live cases are considered in the overall clinical study results. This article discusses CDRH's regulatory view of live case presentations with a focus on patient safety, clinical trial integrity, and concerns regarding improper medical device promotion.

Premarket clinical evaluation of novel cardiovascular devices: quality analysis of premarket clinical studies submitted to the Food and Drug Administration 2000-2007.

The quality of clinical data submitted by manufacturers to support Food and Drug Administration cardiovascular device premarket approval (PMA) applications varies widely and formal quality assessment has not been previously performed. This study evaluated all original cardiovascular device PMAs with Food and Drug Administration decisions between January 1, 2000, and December 31, 2007, to assess the quality of clinical investigations submitted by manufacturers. Effectiveness and safety end points were judged high quality if they were clearly defined and associated with a specific time point for analysis. Subject accounting was high quality if 90% or greater of the original cohort was accounted for at study conclusion. In total, 88 cardiovascular device PMAs (77.3% permanent implants), 132 clinical studies, 37,328 study subjects (age 61.0 +/- 14.5 years, 33.9% women, 86.3% white), and 29,408 device recipients were analyzed. All PMAs contained clinical data. Primary effectiveness end points, primary safety end points, and subject accounting were deemed high quality in 81.8%, 60.2%, and 77.3% of pivotal studies, respectively. Key cardiovascular comorbidities (coronary artery disease 51.1%, diabetes 36.6%, hypertension 35.2%, heart failure 37.5%, tobacco use 31.8%) and race (14.8%) were infrequently reported, and studies rarely included patients younger than 18 years of age (10.2% of studies). Poorly defined safety and effectiveness end points, poor patient accounting, and incomplete collection of important patient comorbidities make device safety and effectiveness assessments more challenging. Women, pediatric, and nonwhite populations are underrepresented in premarket cardiovascular clinical trials. Manufacturers, regulators, and the clinical community should collaborate to address these study shortcomings to ensure that patients are treated with reliable, safe, and clinically useful medical devices.

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.

FDA perspective on objective performance goals and clinical trial design for evaluating catheter-based treatment of critical limb ischemia.

The article by Conte et al.(1) on behalf of the Society for Vascular Surgery (SVS) in this issue of the Journal of Vascular Surgery provides guidelines for improving the consistency and interpretability of clinical trials intended to evaluate treatment options for patients with critical limb ischemia (CLI). This article identifies a number of key challenges with conducting and comparing CLI trials, including the wide spectrum of clinical presentations that CLI encompasses, the use of disparate eligibility criteria and endpoint measurements, and logistical and economic considerations that can limit study initiation and completion. The authors propose definitions for a number of performance goals derived from historical surgical literature as a means of reducing the negative impact of these factors. The current editorial reviews aspects of this proposal from the perspective of the authors in terms of their understanding of the statutory obligations of the U.S. Food and Drug Administration (FDA) to regulate the marketing of cardiovascular devices based on valid scientific evidence.

Integrating Quality of Life and Survival Outcomes in Cardiovascular Clinical Trials.

Background Survival and health status (eg, symptoms and quality of life) are key outcomes in clinical trials of heart failure treatment. However, health status can only be recorded on survivors, potentially biasing treatment effect estimates when there is differential survival across treatment groups. Joint modeling of survival and health status can address this bias. Methods and Results We analyzed patient-level data from the PARTNER 1B trial (Placement of Aortic Transcatheter Valves) of transcatheter aortic valve replacement versus standard care. Health status was quantified with the Kansas City Cardiomyopathy Questionnaire (KCCQ) at randomization, 1, 6, and 12 months. We compared hazard ratios for survival and mean differences in KCCQ scores at 12 months using several models: the original growth curve model for KCCQ scores (ignoring death), separate Bayesian models for survival and KCCQ scores, and a Bayesian joint longitudinal-survival model fit to either 12 or 30 months of survival follow-up. The benefit of transcatheter aortic valve replacement on 12-month KCCQ scores was greatest in the joint-model fit to all survival data (mean difference, 33.7 points; 95% credible intervals [CrI], 24.2-42.4), followed by the joint-model fit to 12 months of survival follow-up (32.3 points; 95% CrI, 22.5-41.5), a Bayesian model without integrating death (30.4 points; 95% CrI, 21.4-39.3), and the original growth curve model (26.0 points; 95% CI, 18.7-33.3). At 12 months, the survival benefit of transcatheter aortic valve replacement was also greater in the joint model (hazard ratio, 0.50; 95% CrI, 0.32-0.73) than in the nonjoint Bayesian model (0.54; 95% CrI, 0.37-0.75) or the original Kaplan-Meier estimate (0.55; 95% CI, 0.40-0.74). Conclusions In patients with severe symptomatic aortic stenosis and prohibitive surgical risk, the estimated benefits of transcatheter aortic valve replacement on survival and health status compared with standard care were greater in joint Bayesian models than other approaches.

Design of a "Lean" Case Report Form for Heart Failure Therapeutic Development.

The development of treatments for heart failure (HF) is challenged by burdensome clinical trials. Reducing the need for extensive data collection and increasing opportunities for data compatibility between trials may improve efficiency and reduce resource burden. The Heart Failure Collaboratory (HFC) multi-stakeholder consortium sought to create a lean case report form (CRF) for use in HF clinical trials evaluating cardiac devices. The HFC convened patients, clinicians, clinical researchers, the U.S. Food and Drug Administration (FDA), payers, industry partners, and statisticians to create a consensus core CRF. Eight recent clinical trial CRFs for the treatment of HF from 6 industry partners were analyzed. All CRF elements were systematically reviewed. Those elements deemed critical for data collection in HF clinical trials were used to construct the final, harmonized CRF. The original CRFs included 176 distinct data items covering demographics, vital signs, physical examination, medical history, laboratory and imaging testing, device therapy, medications, functional and quality of life assessment, and outcome events. The resulting, minimally inclusive CRF device contains 75 baseline data items and 6 events, with separate modular additions that can be used depending on the additional detail required for a particular intervention. The consensus electronic form is now freely available for use in clinical trials. Creation of a core CRF is important to improve clinical trial efficiency in HF device development in the United States. This living document intends to reduce clinical trial administrative burden, increase evidence integrity, and improve comparability of clinical data between trials.

The 21st Century Cures Act and Early Feasibility Studies for Cardiovascular Devices: What Have We Learned, Where Do We Need to Go?

Performance of early feasibility studies in the United States can advance the goal of evaluating the safety and effectiveness of new devices aimed at unmet clinical needs and facilitating earlier access for U.S. patients to new technology. Early feasibility studies are an important component of the 21st Century Cures Act, enacted by Congress in 2016. Although regulatory processes have improved since the introduction of the Early Feasibility Studies Program, impediments at the hospital and clinical site level remain. In this paper, the authors review these issues and outline the structure and function of a clinical site consortium designed to address the problems and improve the U.S. clinical trial ecosystem.

Improving Heart Failure Therapeutics Development in the United States: The Heart Failure Collaboratory.

The current heart failure clinical trial environment is strained by increasing complexity and cost, regulatory requirements, competing demands on stakeholders, implementation challenges, and decreasing patient and investigator participation. To begin the process of developing potentially effective strategies and tactics, stakeholders including patients; investigators; academic leaders; pharmaceutical and device industry representatives; society representatives; third-party payers; and government representatives from the U.S. Food and Drug Administration, National Institutes of Health, and Centers for Medicare and Medicaid Services convened in March of 2017. This paper summarizes the discussions, outlines current challenges and actionable opportunities, and makes targeted recommendations to achieve the goals of improving efficiency in clinical trials and speeding the development of effective heart failure therapies, including the formation of an organized Heart Failure Collaboratory.