Montreal Heart Institute

Multimodal exercise programs do not specifically target lumbar paraspinal musculature, but incorporate aspects of different exercises to have an overall benefit. To investigate the effect of a multimodal exercise program on paraspinal muscle volume and composition, and patient outcomes in individuals with chronic low back pain (CLBP). Thirty-four participants with CLBP either completed a 14-week high-intensity training program (n = 8) including cardiorespiratory and resistance exercises 3 sessions per week or were waitlisted (n = 26). Participants underwent magnetic resonance imaging at baseline and post-intervention to assess paraspinal muscle volume (cm3) and fatty infiltration (% FI) at L3-L4, L4-L5, and L5-S1. Pain, disability, quality of life, pain-related fear (catastrophizing and Kinesiophobia), and anxiety were assessed via validated self-reported questionnaires. Mixed-design ANOVA revealed no significant time × group interactions for paraspinal muscle volume and %FI. An exploratory analysis revealed a significant increase in multifidus %FI in the control group at L3-L4, L4-L5, and L5-S1, with a concomitant increase in multifidus volume at L3-L4 and L5-S1. The exercise group had a significant increase in multifidus %FI and volume at L5-S1. Significant time × group interactions for pain, disability, catastrophizing and kinesiophobia, and a main effect of group in physical and mental health were found. Significant correlations were found between changes in patient-reported and functional outcomes with paraspinal muscle morphology. Multimodal exercise programs may help prevent LBP-related paraspinal muscle atrophy and %FI, and lead to concomitant improvements in pain, disability and pain-related fear in individuals with CLBP.

Abstract Coronary artery disease increases risk of cognitive decline and stroke and is associated with white matter alterations. However, the biological basis of these changes remains unclear. Myelin content and iron deposition are crucial measures of white matter health and can be measured with quantitative MRI. This study investigated whether myelin and iron alterations occur in coronary artery disease, and their relationship with cognition. In this cross-sectional study, 46 individuals with coronary artery disease and 40 healthy controls aged > 50 years, with normal cognition underwent 3T MRI and cognitive assessments. Quantitative MRI metrics (susceptibility, magnetization transfer saturation, R 2 ∗ and R 1 relaxation rates) were calculated in the border zones between adjacent arterial territories (watershed regions) and in the areas outside these borders (non-watershed regions). Relative to controls, the coronary artery disease group showed lower myelin and higher iron content, as measured by lower magnetization transfer saturation and R 1 , and higher susceptibility specifically in watershed regions. Importantly, these microstructural alterations were associated with poorer cognitive performance in the coronary artery disease group with lower magnetization transfer and R 1 related to poorer global cognition and with higher magnetic susceptibility with poorer verbal memory. These findings suggest that coronary artery disease is associated with demyelination and iron deposition in white matter, most prominently in watershed regions, which are known for their susceptibility to stroke. The association of these microstructural alterations with cognition highlights the role of white matter as a key vulnerable region and a promising focus for future mechanistic and therapeutic studies.

The purpose was to characterize the physiological responses resulting from a newly developed treadmill firefighting simulation and to compare these responses with those induced by live fire and simulated firefighting activities reported in different studies. Forty participants (four women) (25 ± 6 years) performed a 25-minute treadmill firefighting simulation that consisted of various tasks completed on a typical work-rest cycle at an imposed rhythm in a temperate environment (ambient temperature: 22.6°C ± 0.6°C, relative humidity: 29.7% ± 11.6%). Rectal temperature increased by 0.56°C ± 0.15°C; peak and mean oxygen consumption were 35.3 ± 3.3 and 20.8 ± 1.7 mL·kg -1 ·min -1 , respectively; and 1169 ± 182 L of air was used. These results show that the treadmill firefighting simulation induces similar physiological responses to those reported for live fire and simulated firefighting scenarios.

ABSTRACTAcute chest syndrome (ACS) is a severe complication of sickle cell disease (SCD) occurring in ~50% of patients, some presenting frequent episodes. We lack tools to identify patients at high risk of ACS occurrence or frequent episodes. Epidemiological studies have found an association between asthma and ACS, but whether this link is causal is unclear. We used polygenic scores (PGS) to analyze whether the genetic propensity for asthma was associated with ACS and could be used to stratify the risk of ACS. We identified that PGS for asthma (PGSasthma) was associated with ACS rate (number of episodes per year), but not ACS occurrence, in both the CSSCD (n = 1278) and the GEN‐MOD (n = 406) prospective SCD cohorts, independently of fetal hemoglobin (HbF) (β = 0.17, standard error = 0.06, p = 0.006). This effect was most pronounced in patients with low HbF levels. Combining PGSasthma and HbF identified a population at high risk of frequent ACS after a first episode: individuals within the highest PGSasthma quintile and the lowest HbF quintile. Finally, we found that the genetic correlation between these two conditions only partially overlapped. This suggests that genetically determined asthma is not the unique contributor to the genetic propensity for ACS and that other genetic determinants may also play a role. In sum, our results suggest that patients with a high genetic propensity for asthma are prone to frequent ACS if not protected by high HbF levels. Combining PGSasthma and HbF may allow identifying patients at high risk of frequent ACS after a first episode for personalized management.

Although Valsalva maneuver (VM) remains the guideline-directed emergent treatment for supraventricular tachycardia (SVT), its success rate remains suboptimal. To assess the efficacy of a novel handheld Valsalva assist device, which can assist in achieving and maintaining target intrathoracic pressures, in improving sinus rhythm restoration rates in patients with SVT. This single-center, open-label randomized clinical trial conducted at Beijing Anzhen Hospital randomized patients with SVT (aged 16-80 years, enrolled between April 2022 and April 2023) undergoing electrophysiological study at a tertiary hospital. Data analysis was completed from January 2024 to January 2025. Participants received either device-assisted VM (n = 106) or standard VM (n = 106) during induced SVT. The primary outcome was immediate cardioversion success (12-lead electrocardiogram-confirmed sinus rhythm within 1 minute) postintervention by intention-to-treat analysis. A total of 212 patients were randomized, among whom 210 completed the randomly assigned VM and were included in the primary analysis (106 in the standard VM group and 104 in the device-assisted VM group). Mean (SD) patient age was 48.4 (14.0) years, and 114 patients (54.8%) were female. After 2 VMs, 67 of 106 participants in the VM with device assist group (63.2%) vs 31 of 106 participants in the standard VM group (29.2%) converted to sinus rhythm within 1 minute (odds ratio, 4.16; 95% CI, 2.36-7.47; P < .001). Per the results of this randomized clinical trial, the handheld Valsalva assist device significantly enhances VM effectiveness, providing a potentially implementable solution for SVT management. ClinicalTrials.gov Identifier: NCT06622772.

<h2>Abstract</h2><h3>Background</h3> There is limited real-world data on the demographic and clinical characteristics of adult patients with obstructive hypertrophic cardiomyopathy (oHCM) treated with mavacamten in Canada. <h3>Methods</h3> This was an observational retrospective cohort study on adult patients with symptomatic oHCM enrolled in the mavacamten Patient Support Program (PSP) in Canada between January 4, 2023, and April 12, 2024. Baseline demographic information, clinical characteristics, medical history, and mavacamten treatment information were collected from the PSP database. <h3>Results</h3> A total of 683 patients met the eligibility criteria for the study. The median age was 65.0 years (IQR: 57.0-73.0), 52.1% of the patients were male, and 67.1% were classified as NYHA class II at baseline. Most patients were on beta blocker monotherapy at baseline (63.7%) and data cut-off (76.3%). Almost all patients (99.4%) were initiated with 5 mg of mavacamten. The median follow-up time was 27.4 weeks (range: 1.6-70.1), and the median treatment duration was 24.6 weeks (range: 0.4-64.4). At data cut-off, 17.1% of patients were on 2.5 mg of mavacamten, 52.6% were on 5 mg, 20.2% were on 10 mg, and 2.2% were on 15 mg. Mavacamten was discontinued by 7.9% of patients, with the main reasons being side effect or adverse event (2.5%; 17/683), undisclosed physician decision (1.8%; 12/683), or lack of efficacy (0.9%; 6/683). <h3>Conclusions</h3> These early results provide the largest dataset on mavacamten utilization in the Canadian oHCM population. Baseline demographic and clinical characteristics and mavacamten dose distributions are comparable to findings from clinical trials and real-world studies. NCT06549608.