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.

A conserved core region of the scaffold NEMO is essential for signal-induced conformational change and liquid-liquid phase separation.

Scaffold proteins help mediate interactions between protein partners, often to optimize intracellular signaling. Herein, we use comparative, biochemical, biophysical, molecular, and cellular approaches to investigate how the scaffold protein NEMO contributes to signaling in the NF-κB pathway. Comparison of NEMO and the related protein optineurin from a variety of evolutionarily distant organisms revealed that a central region of NEMO, called the Intervening Domain (IVD), is conserved between NEMO and optineurin. Previous studies have shown that this central core region of the IVD is required for cytokine-induced activation of IκB kinase (IKK). We show that the analogous region of optineurin can functionally replace the core region of the NEMO IVD. We also show that an intact IVD is required for the formation of disulfide-bonded dimers of NEMO. Moreover, inactivating mutations in this core region abrogate the ability of NEMO to form ubiquitin-induced liquid-liquid phase separation droplets in vitro and signal-induced puncta in vivo. Thermal and chemical denaturation studies of truncated NEMO variants indicate that the IVD, while not intrinsically destabilizing, can reduce the stability of surrounding regions of NEMO due to the conflicting structural demands imparted on this region by flanking upstream and downstream domains. This conformational strain in the IVD mediates allosteric communication between the N- and C-terminal regions of NEMO. Overall, these results support a model in which the IVD of NEMO participates in signal-induced activation of the IKK/NF-κB pathway by acting as a mediator of conformational changes in NEMO.

Retinal Ischemic Perivascular Lesions in Individuals With Atrial Fibrillation.

Background We previously demonstrated that retinal ischemic perivascular lesions (RIPLs), which are indicative of ischemia in the middle retina, may be a biomarker of ischemic cardiovascular disease. In this study, we sought to determine the relationship between RIPLs and atrial fibrillation, a common source of cardiac emboli. Methods and Results In this case-control study, we identified individuals between the ages of 50 and 90 years who had undergone macular spectral domain optical coherence tomography imaging. Individuals with atrial fibrillation were identified, and age- and sex-matched individuals from the same pool, but without a diagnosis of atrial fibrillation, were selected as controls. Spectral domain optical coherence tomography scans were reviewed by 3 independent and masked observers for presence of RIPLs. The relationship between RIPLs and atrial fibrillation was analyzed using multivariable logistic regression models. There were 106 and 91 subjects with and without atrial fibrillation, respectively. The percentage of subjects with RIPLs was higher in the atrial fibrillation group compared with the control group (57.5% versus 37.4%; P=0.005). After adjusting for age, sex, smoking history, hypertension, diabetes, coronary artery disease, carotid stenosis, stroke, and myocardial infarction, the presence of RIPLs was significantly associated with atrial fibrillation, with an odds ratio of 1.91 (95% CI, 1.01-3.59). Conclusions RIPLs are significantly associated with atrial fibrillation, independent of underlying ischemic heart disease or cardiovascular risk factors. This association may inform the diagnostic cardiovascular workup for individuals with RIPLs incidentally detected on optical coherence tomography scan of the macula.

Physician assessment of aortic stenosis severity, quantitative parameters, and long-term outcomes: Results from the KP-VALVE project.

BACKGROUND: Contemporary outcomes for aortic stenosis (AS) and the association between physician-assessed AS severity and quantitative parameters is poorly understood. We aimed to evaluate AS natural history, compare outcomes for physicians' AS assessment vs. quantitative parameters, and identify AS parameters with the most explanatory power. METHODS: We ascertained physician-assessed AS severity, echocardiographic parameters, and clinical data for 546,769 patients from 2008-2018, examined multivariable associations of physician-assessed AS severity and number of quantitative severe AS parameters with death, cardiovascular hospitalization, and aortic valve replacement, and estimated the relative contribution of different quantitative AS parameters on outcomes. RESULTS: Among 49,604 AS patients (mean [SD] age 77 [11] years), 17.6% had moderate, 3.6% moderate-severe, and 9.4% severe AS. During median 3.7 [IQR 1.7-6.8] years, physician-assessed AS severity strongly correlated with outcomes, with moderate AS patients tracking closest to mild AS, and moderate-to-severe AS patients more comparable to severe AS. Although the number of quantitative severe AS parameters strongly predicted outcomes (adjusted HR [95% CI] for death 1.40 [1.34-1.46], 1.70 [1.56-1.85], and 1.78 [1.63-1.94] for 1, 2, and 3 parameters, respectively), aortic valve area <1.0 cm2 was the most frequent severe AS parameter, explained the largest relative contribution (67%), and was common in patients classified as moderate (21%) or moderate-severe (56%) AS. CONCLUSIONS: Physician-assessed AS severity predicts outcomes, with cumulative effects for each severe AS parameter. Moderate AS includes a wide spectrum of patients, with discordant AVA <1.0 cm2 being both common and predictive. Better identification of non-classical severe AS phenotypes may improve outcomes.

A Conserved Core Region of the Scaffold NEMO is Essential for Signal-induced Conformational Change and Liquid-liquid Phase Separation.

Scaffold proteins help mediate interactions between protein partners, often to optimize intracellular signaling. Herein, we use comparative, biochemical, biophysical, molecular, and cellular approaches to investigate how the scaffold protein NEMO contributes to signaling in the NF-κB pathway. Comparison of NEMO and the related protein optineurin from a variety of evolutionarily distant organisms revealed that a central region of NEMO, called the Intervening Domain (IVD), is conserved between NEMO and optineurin. Previous studies have shown that this central core region of the IVD is required for cytokine-induced activation of IκB kinase (IKK). We show that the analogous region of optineurin can functionally replace the core region of the NEMO IVD. We also show that an intact IVD is required for the formation of disulfide-bonded dimers of NEMO. Moreover, inactivating mutations in this core region abrogate the ability of NEMO to form ubiquitin-induced liquid-liquid phase separation droplets in vitro and signal-induced puncta in vivo. Thermal and chemical denaturation studies of truncated NEMO variants indicate that the IVD, while not intrinsically destabilizing, can reduce the stability of surrounding regions of NEMO, due to the conflicting structural demands imparted on this region by flanking upstream and downstream domains. This conformational strain in the IVD mediates allosteric communication between N- and C-terminal regions of NEMO. Overall, these results support a model in which the IVD of NEMO participates in signal-induced activation of the IKK/NF-κB pathway by acting as a mediator of conformational changes in NEMO.

Validation of American Society of Echocardiography Guideline-Recommended Parameters of Right Ventricular Dysfunction Using Artificial Intelligence Compared With Cardiac Magnetic Resonance Imaging.

BACKGROUND: Right ventricular (RV) function is important in the evaluation of cardiac function, but its assessment using standard transthoracic echocardiography (TTE) remains challenging. Cardiac magnetic resonance imaging (CMR) is considered the gold standard. The American Society of Echocardiography recommends surrogate measures of RV function and RV ejection fraction (RVEF) by TTE, including fractional area change (FAC), free wall strain (FWS), and tricuspid annular planar systolic excursion (TAPSE), but they require technical expertise in acquisition and quantification. METHODS: The aim of this study was to evaluate the sensitivity, specificity, and positive and negative predictive values of FAC, FWS, and TAPSE derived using a rapid, novel artificial intelligence (AI) software (LVivoRV) from a single-plane transthoracic echocardiographic apical four-chamber, RV-focused view without ultrasound-enhancing agents for detecting abnormal RV function compared with CMR-derived RVEF. RV dysfunction was defined as RVEF < 50% and RVEF < 40% on CMR. RESULTS: TTE and CMR were performed within a median of 10 days (interquartile range, 2-32 days) of each other in 225 consecutive patients without interval procedural or pharmacologic intervention. The sensitivity and negative predictive value to detect CMR-defined RV dysfunction when all three AI-derived parameters (FAC, FWS, and TAPSE) were abnormal were 91% and 96%, while those of expert physician reads were 91% and 97%. Specificity and positive predictive value were lower (50% and 32%) compared with expert physician-read echocardiograms (82% and 56%). CONCLUSIONS: AI-derived measurements of FAC, FWS, and TAPSE had excellent sensitivity and negative predictive value for ruling out significant RV dysfunction (CMR RVEF < 40%), comparable with that of expert physician readers, but lower specificity. Thus AI, using American Society of Echocardiography guidelines, may serve as a useful screening tool for rapid bedside assessment to exclude significant RV dysfunction.

Role of Quantitation of Saline Bubble Studies in Patients with Liver Cirrhosis.

OBJECTIVE: Microbubble contrast echocardiography with a late positive signal enables the detection of intrapulmonary vascular dilation, including hepatopulmonary syndrome, in patients with end-stage liver disease. We assessed the relationship between the severity of bubble study and clinical outcome. METHODS: We retrospectively analyzed 163 consecutive patients with liver cirrhosis who underwent an echocardiogram with bubble study from 2018 to 2021. Patients who were diagnosed with a late positive signal were divided into three groups: grade 1 (1-9 bubbles), grade 2 (10-30 bubbles) and grade 3 (>30 bubbles). RESULTS: Fifty-six percent of the patients had a late positive bubble study (grade 1: 31%, grade 2: 23%, grade 3: 46%). Patients with grade 3 had a significantly higher international normalized ratio, model for end-stage liver disease score and Child-Pugh score and a lower peripheral oxygen saturation compared with patients with a negative study. In patients undergoing liver transplant (LT), survival rates were similar among the groups (3-mo: >87%, 1-y: >87%, 2-y: >83%). However, survival rate was lower in grade 3 patients without LT (3-mo: 81%, 1-y: 64%, 2-y: 39%). CONCLUSION: Patients with grade 3 had much worse mortality without LT compared with other groups. However, after LT, all grades had equal survival. Therefore, patients with grade 3 may be considered as higher priority for LT.

Intravascularly infused extracellular matrix as a biomaterial for targeting and treating inflamed tissues.

Decellularized extracellular matrix in the form of patches and locally injected hydrogels has long been used as therapies in animal models of disease. Here we report the safety and feasibility of an intravascularly infused extracellular matrix as a biomaterial for the repair of tissue in animal models of acute myocardial infarction, traumatic brain injury and pulmonary arterial hypertension. The biomaterial consists of decellularized, enzymatically digested and fractionated ventricular myocardium, localizes to injured tissues by binding to leaky microvasculature, and is largely degraded in about 3 d. In rats and pigs with induced acute myocardial infarction followed by intracoronary infusion of the biomaterial, we observed substantially reduced left ventricular volumes and improved wall-motion scores, as well as differential expression of genes associated with tissue repair and inflammation. Delivering pro-healing extracellular matrix by intravascular infusion post injury may provide translational advantages for the healing of inflamed tissues 'from the inside out'.

Retinal vein occlusion is associated with stroke independent of underlying cardiovascular disease.

BACKGROUND: Stroke is a leading cause of mortality and morbidity. Thus, identifying associated risk factors may lead to earlier interventions aimed at reducing the risk of stroke development. Since cardiovascular disease simultaneously increases the risk of stroke and retinal vein occlusion (RVO), we sought to determine whether RVO is associated with the risk of stroke independent of underlying cardiovascular co-morbidities. METHODS: In this cross-sectional study, we reviewed the records of 80,754 individuals who were evaluated by an ophthalmologist over a 6-year period. We identified individuals with RVO, stroke and cardiovascular diseases including hypertension, diabetes mellitus, carotid disease, coronary artery disease and atrial fibrillation. Multivariable logistic regression models were used to analyze odds ratios for RVO and stroke. RESULTS: After adjusting for age, sex, cardiovascular disease and other risk factors, we found that the presence of RVO was associated with an odds ratio for stroke of 1.73 (CI, 1.40-2.12, p < 0.001). The association between RVO and stroke, after adjusting for sex and cardiovascular co-morbidities, was significantly stronger in individuals younger than 50 years of age, with an odds ratio of having a stroke of 3.06 (1.34-6.25, p < 0.001), while the presence of RVO in individuals older than 85 years was not significantly associated with stroke 1.19 (0.77-1.79, p = 0.41). CONCLUSIONS: Our findings demonstrate that RVO is significantly associated with stroke, even after adjusting for underlying cardiovascular co-morbidities. This association was highly significant in younger subjects, while not significant in older individuals.