The field of cardio-immunology has emerged from discoveries that define roles for innate and adaptive immune responses associated with myocardial inflammation and heart failure. Dendritic cells (DCs) comprise an important cellular compartment that contributes to systemic immune surveillance at the junction of innate and adaptive immunity. Once described as a singular immune subset, we now appreciate that DCs consist of a heterogeneous pool of subpopulations, each with distinct effector functions that can uniquely regulate the acute and chronic inflammatory response. Nevertheless, the cardiovascular-specific context involving DCs in negotiating the biological response to myocardial injury is not well understood. Herein, we review our current understanding of the role of DCs in cardiac inflammation and heart failure, including gaps in knowledge and clinical relevance.

Obstructive hypertrophic cardiomyopathy (HCM) is associated with significant morbidity attributed to left ventricular outflow tract (LVOT) obstruction. Although alcohol septal ablation (ASA) is an established interventional treatment, mavacamten, a novel cardiac myosin inhibitor, has emerged as a noninvasive pharmacologic alternative. Understanding the comparative efficacy of these 2 treatments is important for optimizing patient care. This single-center retrospective study assessed the hemodynamic and functional changes in adult patients with obstructive HCM treated with ASA (n = 58) or mavacamten (n = 36) from July 2012 to May 2024. Outcomes, including changes in LVOT gradient, left ventricular ejection fraction, mitral regurgitation (MR) severity, and New York Heart Association (NYHA) class, were collected at baseline, 16 weeks, and after 32 weeks of treatment. ASA and mavacamten were associated with over 70% reductions in Valsalva-induced LVOT gradient and MR after 32 weeks. The maximal effect of ASA on LVOT gradient was observed at 16 weeks, whereas mavacamten's peak effect was noted after 32 weeks. MR severity improved similarly in both cohorts (p <0.01). Patients who underwent ASA had a poorer baseline NYHA functional class than their counterparts; however, each treatment significantly improved LVOT gradients (p <0.001) and average NYHA class after 32 weeks (p <0.001). The average left ventricular ejection fraction was comparable at baseline and after 32 weeks between the 2 groups. Patients treated with ASA were older than those treated with mavacamten (68.5 vs 60.8 years, p <0.001). In patients with obstructive HCM, ASA and mavacamten yield significant and comparable improvements in hemodynamics and functional status after 32 weeks.

This study presents an elderly man with sequential hemodynamic obstructions caused by hypertrophic cardiomyopathy and aortic stenosis. Septal reduction therapy was performed to avoid outflow tract obstruction associated with potential future transcatheter aortic valve replacement. This case highlights the importance of resolving outflow tract obstruction during assessment of aortic valve disease.

Background: This study aims to understand and describe the clinical impact of SARS-CoV-2 (COVID-19) infection in patients with Hypertrophic Cardiomyopathy (HCM). Methods: A data repository of over 6.6 million patients in a large metropolitan (Chicago IL) healthcare system was queried to identify adults with a history of HCM and COVID-19 infection between 2019 and 2021. Propensity score-matched analysis was performed based on age, sex, BMI, and elements of the cardiovascular history, including tobacco use, hypertension, hyperlipidemia, myocardial injury, and heart failure. Results: Individuals with HCM and COVID-19 infection had more total hospitalizations (41.6 v 23 per 100 persons, p < 0.01), more heart-failure-related hospitalizations (24.2 v 8.7 per 100-persons, p < 0.01), more non-ST elevation myocardial injury (NSTEMI) hospitalizations (8.6 v 4.6 per 100-persons, p < 0.01), and increased mortality (10.8 v 5 per 100-persons, p < 0.01) compared to HCM patients without a history of COVID-19 infection. Patients with HCM and COVID-19 were also noted to have a higher peak CRP when compared to those without prior COVID-19 (Inter-quartile range of 9.0–106.9 v 1.8–21.3, p < 0.01). Conclusions: In patients with HCM, COVID-19 infection is associated with increased incidence of myocardial injury, increased number of total and heart-failure specific hospitalizations, and increased mortality.

Objectives: This study examines whether anterior mitral valve leaflet (AMVL) length is associated with response to mavacamten in patients with obstructive hypertrophic cardiomyopathy (HCM). Aims: Obstruction of the left-ventricular outflow tract (LVOT) in HCM has been associated with asymmetric septal hypertrophy and abnormalities of the mitral valve and sub-valvular apparatus. Mavacamten is a myosin-inhibitor shown to decrease LVOT gradient and improve functional status in patients with obstructive HCM. Methods and results: Measurements of cardiac structural elements were obtained from magnetic resonance imaging and echocardiography data among patients with obstructive HCM treated with mavacamten. Endpoints were effective mavacamten dose, defined as the dose required to achieve a Valsalva LVOT gradient <30 mmHg, and rapid response to mavacamten therapy, defined as achieved Valsalva LVOT gradient <20 mmHg within 8 weeks of initiation. Among 33 patients, patients with an effective dose of 5 mg (n = 13) had a shorter AMVL length [20.00 (18.50, 20.80) mm] compared with patients with a dose of 10 mg (n = 12) [23.30 (22.45, 26.10) mm] and 15 mg (n = 8) [25.45 (24.20, 26.85) mm] (P < 0.001). After adjusting for age and sex, the 5 mg dose was associated with a shorter AMVL length (P = 0.003). AMVL length was shorter in rapid responders [20.9 (19.9, 22.5) mm] compared with patients without a rapid response [24.9 (23.3, 26.5) mm] (P = 0.006). Conclusion: Shorter AMVL length is associated with a lower effective dose and a rapid response to mavacamten. If confirmed in larger studies, AMVL length may inform optimal dosing of myosin inhibitors in obstructive HCM.