Athlete's Heart Revisited: Historical, Clinical, and Molecular Perspectives.

The athlete's heart, formally introduced by Henschen and Darling in 1899 through observations of cardiac enlargement in endurance athletes, has evolved from a clinical curiosity to a recognized physiological adaptation. Even before this naming, similar constructs such as the soldier's heart in military recruits and the runner's heart in distance athletes suggested early observations of exercise-associated cardiac remodeling-often pathologized or mischaracterized. Today, this phenomenon is understood as exercise-induced cardiac remodeling, comprising structural, functional, and electrical changes that support the demands of sustained athletic performance.

Diffusion Tensor Phenomapping of the Healthy and Pressure-Overloaded Human Heart.

Current techniques to image the microstructure of the heart with diffusion tensor MRI (DTI) are highly under-resolved. We present a technique to improve the spatial resolution of cardiac DTI by almost 10-fold and leverage this to measure local gradients in cardiomyocyte alignment or helix angle (HA). We further introduce a phenomapping approach based on voxel-wise hierarchical clustering of these gradients to identify distinct microstructural microenvironments in the heart.

Home Hospital Outcomes for Acute Decompensated Heart Failure and Factors Associated With Escalation of Care.

Background: Overall outcomes and the escalation rate for home hospital admissions for heart failure (HF) are not known. We report overall outcomes, predict escalation, and describe care provided after escalation among patients admitted to home hospital for HF.

Methods: Our retrospective analysis included all patients admitted for HF to 2 home hospital programs in Massachusetts between February 2020 and October 2022.

Utility of the oxygen pulse in the diagnosis of obstructive coronary artery disease in physically fit patients.

Cardiopulmonary exercise testing (CPET) guidelines recommend analysis of the oxygen (O ) pulse for a late exercise plateau in evaluation for obstructive coronary artery disease (OCAD). However, whether this O pulse trajectory is within the range of normal has been debated, and the diagnostic performance of the O pulse for OCAD in physically fit individuals, in whom may be more likely to plateau, has not been evaluated. Using prospectively collected data from a sports cardiology program, patients were identified who were free of other cardiac disease and underwent clinically-indicated CPET within 90 days of invasive or computed tomography coronary angiography.

Detection and Characterization of Thrombosis in Humans Using Fibrin-Targeted Positron Emission Tomography and Magnetic Resonance.

Objectives: The authors present a novel technique to detect and characterize LAA thrombus in humans using combined positron emission tomography (PET)/cardiac magnetic resonance (CMR) of a fibrin-binding radiotracer, [Cu]FBP8.

Background: The detection of thrombus in the left atrial appendage (LAA) is vital in the prevention of stroke and is currently performed using transesophageal echocardiography (TEE).

Methods: The metabolism and pharmacokinetics of [Cu]FBP8 were studied in 8 healthy volunteers.

Normative cardiopulmonary exercise data for endurance athletes: the Cardiopulmonary Health and Endurance Exercise Registry (CHEER).

Aims: Accurate interpretation of cardiopulmonary exercise testing (CPET) relies on age, gender, and exercise modality-specific reference values. To date, clinically applicable CPET reference values derived from a source population of endurance athletes (EAs) have been lacking. The purpose of this study was to generate CPET reference values for use in the clinical assessment of EA.

Cardiac Structure and Function in Elite Female and Male Soccer Players.

Importance: Population-specific normative data are essential for the evaluation of competitive athletes. At present, there are limited data defining normal electrocardiographic (ECG) and echocardiographic values among elite US soccer players.

Objective: To describe ECG and echocardiographic findings in healthy elite US soccer players.

Personalized treatment for coronary artery disease patients: a machine learning approach.

Current clinical practice guidelines for managing Coronary Artery Disease (CAD) account for general cardiovascular risk factors. However, they do not present a framework that considers personalized patient-specific characteristics. Using the electronic health records of 21,460 patients, we created data-driven models for personalized CAD management that significantly improve health outcomes relative to the standard of care.

Impact of Appropriate Use Criteria for Transthoracic Echocardiography in Valvular Heart Disease on Clinical Outcomes.

Background: The association between appropriate use criteria for transthoracic echocardiography (TTE) and clinical outcomes is unknown for patients with valvular heart disease (VHD). The aim of this study was to identify the association of TTE appropriateness with downstream cardiac tests and clinical outcomes in patients with VHD over 365 days.

Methods: A subset of 2,297 patients with VHD across six Ontario academic hospitals was selected from the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial and linked to administrative databases.

Association of Ascending Aortic Dilatation and Long-term Endurance Exercise Among Older Masters-Level Athletes.

Importance: Aortic dilatation is frequently encountered in clinical practice among aging endurance athletes, but the distribution of aortic sizes in this population is unknown. It is additionally uncertain whether this may represent aortic adaptation to long-term exercise, similar to the well-established process of ventricular remodeling.

Objective: To assess the prevalence of aortic dilatation among long-term masters-level male and female athletes with about 2 decades of exercise exposure.

Association Between Physicians' Appropriate Use of Echocardiography and Subsequent Healthcare Use and Outcomes in Patients With Heart Failure.

Background There is little understanding of whether a physician's tendency to order an inappropriate cardiac service is associated with the use of other cardiac services and clinical outcomes in their patients with heart failure (HF). Methods and Results We conducted a secondary analysis of 35 Ontario-based cardiologists who participated in the control arm of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial. Transthoracic echocardiograms, ordered during the trial, were classified as rarely appropriate (rA), appropriate, or maybe appropriate on the basis of the 2011 appropriate use criteria.

Low-Value Transthoracic Echocardiography, Healthcare Utilization, and Clinical Outcomes in Patients With Coronary Artery Disease.

Background: The relationship between ordering frequency of rarely appropriate transthoracic echocardiograms on healthcare utilization and patient outcomes in coronary artery disease (CAD) is not known. Our objective was to investigate practice patterns of cardiologists who order a high frequency of low-value transthoracic echocardiograms in patients with CAD and whether practice behavior influences patient outcomes.

Methods And Results: A retrospective cohort of outpatient CAD patients was accrued by identifying patients with at least 1 visit to 1 of 35 Ontario-based cardiologists in the EchoWISELY randomized clinical trial (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) control group.

Selection of endurance capabilities and the trade-off between pressure and volume in the evolution of the human heart.

Chimpanzees and gorillas, when not inactive, engage primarily in short bursts of resistance physical activity (RPA), such as climbing and fighting, that creates pressure stress on the cardiovascular system. In contrast, to initially hunt and gather and later to farm, it is thought that preindustrial human survival was dependent on lifelong moderate-intensity endurance physical activity (EPA), which creates a cardiovascular volume stress. Although derived musculoskeletal and thermoregulatory adaptations for EPA in humans have been documented, it is unknown if selection acted similarly on the heart.

Myocardial Adaptations to Competitive Swim Training.

Purpose: Swim training is performed in the prone or supine position and obligates water immersion, factors that may augment cardiac volume loading more than other endurance sports. At present, prospective data defining the cardiac responses to swim training are lacking. We therefore studied myocardial adaptations among competitive swimmers to establish a causal relationship between swim training and left ventricular (LV) remodeling.

Diagnostic Yield of Customized Exercise Provocation Following Routine Testing.

Clinical guidelines advocate for customization of exercise testing to address patient-specific diagnostic goals, including reproduction of presenting exertional symptoms. However, the diagnostic yield of adding customized exercise testing to graded exercise in patients presenting with exertional complaints has not been rigorously examined and is the focus of this study. Using prospectively collected data, we analyzed the diagnostic yield of customized additional exercise provocation following inconclusive graded exercise test with measurement of gas exchange.

The application of appropriate use criteria for transthoracic echocardiography in a cardiac intensive care unit.

Background: Appropriate use criteria (AUC) represent an important mechanism by which to promote the rational utilization of healthcare resources. No study to date has been conducted assessing the applicability of current AUC to transthoracic echocardiograms (TTEs) performed in a cardiac intensive care unit (CICU). We analyzed 2 years of consecutive TTEs performed in a CICU at a quaternary-care academic medical center, hypothesizing that current AUC may not adequately describe the role of TTE in a modern CICU.

Association Between Transthoracic Echocardiography Appropriateness and Echocardiographic Findings.

Background: The association between appropriate use criteria and echocardiographic findings in patients with chronic cardiovascular diseases is unknown.

Methods: As a substudy of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial, 9,230 transthoracic echocardiographic (TTE) examinations from six Ontario academic hospitals were linked to a registry of echocardiographic findings. The TTE studies were rated appropriate), rarely appropriate, or may be appropriate according to the 2011 appropriate use criteria.

Catecholamine response to exercise in patients with non-obstructive hypertrophic cardiomyopathy.

Key Points: Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). As a result, the majority of patients with HCM deliberately reduce their habitual physical activity after diagnosis and this lifestyle change puts them at risk for sequelae of a sedentary lifestyle: weight gain, hypertension, hyperlipidaemia, insulin resistance, coronary artery disease, and increased morbidity and mortality. We show that plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold, a parameter that can be defined during cardiopulmonary exercise testing, but rise rapidly at higher intensities of exercise.