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Background and Objective: Coronary artery disease (CAD) and heart failure are the most common cardiovascular diseases. Non-invasive diagnostic testing for CAD requires radiation, heart rate acceleration, and imaging infrastructure. Early detection of left ventricular dysfunction is critical in heart failure management, the best measure of which is an elevated left ventricular end-diastolic pressure (LVEDP) that can only be measured using invasive cardiac catheterization. There exists a need for non-invasive, safe, and fast diagnostic testing for CAD and elevated LVEDP. This research employs nonlinear dynamics to assess for significant CAD and elevated LVEDP using non-invasively acquired photoplethysmographic (PPG) and three-dimensional orthogonal voltage gradient (OVG) signals. PPG (variations of the blood volume perfusing the tissue) and OVG (mechano-electrical activity of the heart) signals represent the dynamics of the cardiovascular system., Methods: PPG and OVG were simultaneously acquired from two cohorts, (i) symptomatic subjects that underwent invasive cardiac catheterization, the gold standard test (408 CAD positive with stenosis≥ 70% and 186 with LVEDP≥ 20 mmHg) and (ii) asymptomatic healthy controls (676). A set of Poincaré-based synchrony features were developed to characterize the interactions between the OVG and PPG signals. The extracted features were employed to train machine learning models for CAD and LVEDP. Five-fold cross-validation was used and the best model was selected based on the average area under the receiver operating characteristic curve (AUC) across 100 runs, then assessed using a hold-out test set., Results: The Elastic Net model developed on the synchrony features can effectively classify CAD positive subjects from healthy controls with an average validation AUC=0.90±0.03 and an AUC= 0.89 on the test set. The developed model for LVEDP can discriminate subjects with elevated LVEDP from healthy controls with an average validation AUC=0.89±0.03 and an AUC=0.89 on the test set. The feature contributions results showed that the selection of a proper registration point for Poincaré analysis is essential for the development of predictive models for different disease targets., Conclusions: Nonlinear features from simultaneously-acquired signals used as inputs to machine learning can assess CAD and LVEDP safely and accurately with an easy-to-use, portable device, utilized at the point-of-care without radiation, contrast, or patient preparation., Competing Interests: Declaration of Competing Interest Mehdi Paak, Farhad Fathieh, Ali Khosousi, Tim Burton, William E. Sanders, Abhinav Doomra, Emmanuel Lange, and Shyam Ramchandani were employees of CorVista® Health. Sanjeev Bhavnani received research grants from Qualcomm Foundation, Scripps Clinic, Bristol Meyers Squibb, Pfizer, and Agency for Healthcare Research and Quality. Further, Sanjeev Bhavnani is a scientific advisor to CorVista® Health and Blumio, a consultant for Bristol Meyers Squibb and Proteus Digital, and an advisory board member to ACC, ASE, and Biocom during this study. Rola Khedraki declares no conflicts of interest to report., (Copyright © 2021. Published by Elsevier B.V.)

Purpose of Review: Refinement in machine learning (ML) techniques and approaches has rapidly expanded artificial intelligence applications for the diagnosis and classification of heart failure (HF). This review is designed to provide the clinician with the basics of ML, as well as this technologies future utility in HF diagnosis and the potential impact on patient outcomes., Recent Findings: Recent studies applying ML methods to unique data sets available from electrocardiography, vectorcardiography, echocardiography, and electronic health records show significant promise for improving diagnosis, enhancing detection, and advancing treatment of HF. Innovations in both supervised and unsupervised methods have heightened the diagnostic accuracy of models developed to identify the presence of HF and further augmentation of model capabilities are likely utilizing ensembles of ML algorithms derived from different techniques., Summary: This article is an overview of recent applications of ML to achieve improved diagnosis of HF and the resultant implications for patient management., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

When not enough women are included in many clinical trials, an information gap on medical device safety and effectiveness exists, which can make it difficult to detect sex-specific results. In this article we discuss potential reasons for the underrepresentation of women and the regulatory research conducted by the U.S. Food and Drug Administration (FDA) used in supporting regulatory decisions. We demonstrate that important differences in cardiovascular device performance between women and men exist. Furthermore, concrete steps are outlined on the possible ways these sex-specific results can be detected and how a recent FDA Action Plan and Guidance Document aim at encouraging female participation in clinical trials and the appropriate analysis thereof.

An important treatment for patients with heart failure is cardiac resynchronization therapy (CRT). Even though only 20% of women were included in clinical trials for CRT, a benefit has been shown in recent studies for subgroups of women compared to their male counterparts. Given this low inclusion rate of women in clinical studies, professional society guideline-based CRT recommendations, such as those by the American College of Cardiology Foundation (ACCF)/American Heart Association (AHA)/Heart Rhythm Society (HRS), may not truly represent the best treatment for women, especially since most of the reports that showed this greater benefit in women were published after the latest guidelines. Despite having research and multiple publications regarding sex-specific heart failure outcomes and response to CRT, the ACCF/AHA/HRS guidelines have not yet been updated to account for the recent information regarding the differences in benefit for women and men with similar patient characteristics. This review discusses the physiology behind CRT, sex-specific characteristics of heart failure, and cardiac electrophysiology and summarizes the current sex-specific literature to encourage consideration of CRT guidelines for women and men separately.

Background: Multiple studies of heart failure patients demonstrated significant improvement in exercise capacity, quality of life, cardiac left ventricular function, and survival from cardiac resynchronization therapy (CRT), but the underenrollment of women in these studies is notable. Etiological and pathophysiological differences may result in different outcomes in response to this treatment by sex. The observed disproportionate representation of women suggests that many women with heart failure either do not meet current clinical criteria to receive CRT in trials or are not properly recruited and maintained in these studies., Methods: We performed a systematic literature review through May 2014 of clinical trials and registries of CRT use that stratified outcomes by sex or reported percent women included. One-hundred eighty-three studies contained sex-specific information., Results: Ninety percent of the studies evaluated included ≤ 35% women. Fifty-six articles included effectiveness data that reported response with regard to specific outcome parameters. When compared with men, women exhibited more dramatic improvement in specific parameters. In the studies reporting hazard ratios for hospitalization or death, women generally had greater benefit from CRT., Conclusions: Our review confirms women are markedly underrepresented in CRT trials, and when a CRT device is implanted, women have a therapeutic response that is equivalent to or better than in men, while there is no difference in adverse events reported by sex.

Background: Women have been under-represented in trials of cardiac resynchronization therapy-defibrillators (CRT-D). Previous studies suggest that women benefit from CRT-D at shorter QRS duration than men and that there may be no benefit of CRT-D in patients without left bundle branch block (LBBB) regardless of patient sex., Methods and Results: We compared sex-specific death risk in 75 079 patients with New York Heart Association class III or IV heart failure, reduced left ventricular ejection fraction, and prolonged QRS duration (≥120 ms) receiving either CRT-D or implantable cardioverter defibrillator in subgroups according to QRS morphology and 10-ms increments in QRS duration. We applied propensity score weighting to control for differences between treatments. Among patients with LBBB, women receiving CRT-D had a lower relative death risk than those receiving an implantable cardioverter-defibrillator (absolute difference, 11%; hazard ratio=0.74 [95% confidence interval, 0.68-0.81]). In men, the lower mortality with CRT-D versus implantable cardioverter defibrillator was less pronounced (absolute difference, 9%; hazard ratio=0.84 [0.79-0.89]; sex×device interaction P=0.025). In those without LBBB, the mortality difference was modest and did not differ between women and men (absolute difference, 3%; hazard ratio=0.88 [0.79-0.97] in women and absolute difference, 2%; hazard ratio=0.95 [0.91-0.998] in men; interaction P=0.17). In subgroups according to QRS duration, CRT-D was associated with better survival in both sexes with LBBB and QRS ≥130 ms, whereas there was no clear relation between QRS duration and survival in patients without LBBB regardless of patient sex., Conclusions: In a large real-world population CRT-D was associated with a lower mortality risk in both sexes with LBBB, although more pronounced among women. Only among those with LBBB, both sexes had better survival with longer QRS duration. The mortality differences in patients without LBBB were attenuated in both sexes., (© 2015 American Heart Association, Inc.)

Importance: Women were underrepresented in cardiac resynchronization therapy (CRT) trials for heart failure (making up about 20% of enrollees). Combining individual patient data from multiple clinical trials would enable assessment of CRT benefit in women., Objective: To evaluate whether women with left bundle branch block (LBBB) benefit from CRT-defibrillators (CRT-D) at a shorter QRS duration than men with LBBB do., Design, Setting, and Participants: Individual patient data were pooled from 3 CRT-D vs implantable cardioverter defibrillator (ICD) trials (4076 patients) enrolling predominantly patients with New York Heart Association (NYHA) class II heart failure and follow-up to 3 years. The effect of CRT-D compared with ICD on outcomes was assessed using random effects Cox proportional hazards., Main Outcomes and Measures: Time to heart failure event or death (primary) and death alone (secondary)., Results: Women benefited from CRT-D more than men. The main difference occurred in patients with LBBB and a QRS of 130 to 149 milliseconds. In this group, women had a 76% reduction in heart failure or death (absolute CRT-D to ICD difference, 23%; hazard ratio [HR], 0.24, [95% CI, 0.11-0.53]; P < .001) and a 76% reduction in death alone (absolute difference 9%; HR, 0.24, [95% CI, 0.06-0.89]; P = .03), while there was no significant benefit in men for heart failure or death (absolute difference 4%; HR, 0.85 [95% CI, 0.60-1.21]; P = .38) or death alone (absolute difference 2%; HR, 0.86 [95% CI, 0.49-1.52]; P = .60). Neither women nor men with LBBB benefited from CRT-D at QRS shorter than 130 milliseconds, while both sexes with LBBB benefited at QRS of 150 milliseconds or longer., Conclusions and Relevance: In this population of patients with primarily mild heart failure, women with LBBB benefited from CRT-D at a shorter QRS duration than men with LBBB. This is important because recent guidelines limit the class I indication for CRT-D to patients with LBBB and QRS of 150 milliseconds or longer. While guidelines do give a class IIa indication to patients with LBBB and a QRS of 120 to 149 milliseconds, the present findings are important to communicate because women are less likely to receive CRT-D than men are. This study exemplifies the potential public health and regulatory science value of combining data from multiple clinical trials submitted to the FDA.

Previous analyses have shown that there is lower mortality with cardiac resynchronization therapy defibrillators (CRT-D) in patients with left bundle branch block (LBBB) but demonstrated mixed results in patients without LBBB. We evaluated the comparative effectiveness of CRT-D versus standard implantable defibrillators (ICDs) separately in patients with LBBB and right bundle branch block (RBBB) using Medicare claims data. Medicare records from CRT-D and ICD recipients from 2002 to 2009 that were followed up for up to 48 months were analyzed. We used propensity scores to match patients with ICD to those with CRT-D. In LBBB, 1:1 matching with replacement resulted in 54,218 patients with CRT-D and 20,763 with ICD, and in RBBB, 1:1 matching resulted in 7,298 patients with CRT-D and 7,298 with ICD. In LBBB, CRT-D had a 12% lower risk of heart failure hospitalization or death (hazard ratio [HR] 0.88, 95% confidence interval 0.86 to 0.90) and 5% lower death risk (HR 0.95, 0.92 to 0.97) compared with ICD. In RBBB, CRT-D had a 15% higher risk of heart failure hospitalization or death (HR 1.15, 1.10 to 1.20) and 13% higher death risk (HR 1.13, 1.07 to 1.18). Sensitivity analysis revealed that accounting for covariates not captured in the Medicare database may lead to increased benefit with CRT-D in LBBB and no difference in RBBB. In conclusion, in a large Medicare population, CRT-D was associated with lower mortality in LBBB but higher mortality in RBBB. The absence of certain covariates, in particular those that determine treatment selection, may affect the results of comparative effectiveness studies using claims data. [ABSTRACT FROM AUTHOR]