Kanaan, Christopher N

Background Connective tissue disorders (CTDs) such as Marfan syndrome, Loeys-Dietz syndrome, and Ehlers-Danlos syndromes are traditionally defined by vascular fragility and aortic complications. Increasing evidence, however, demonstrates that CTDs also predispose to atrial and ventricular arrhythmias, often independent of overt cardiomyopathy or severe valvular disease. Content This review integrates emerging data on the arrhythmogenic substrates of CTDs. Four mechanistic bridges are emphasized: (1) diffuse myocardial fibrosis driven by dysregulated TGF-β signaling, (2) structural valve and annular abnormalities, particularly mitral valve prolapse and mitral annular disjunction, (3) altered mechanotransduction linking extracellular matrix instability to cytoskeletal and nuclear signaling pathways, and (4) downstream ion-channel and gap-junction remodeling as secondary amplifiers. We outline the genetic architecture underlying these processes, focusing on established CTD-implicated genes in the TGF-β/SMAD pathway, valve and annulus regulators, cytoskeletal and myocyte-coupling proteins, and extracellular matrix components, while incorporating emerging CTD modifiers that expand the spectrum of arrhythmia susceptibility. Summary Recognition of CTDs as both vascular and electrical disorders reframes clinical management. Imaging markers such as mitral annular disjunction and diffuse fibrosis, together with targeted ambulatory rhythm monitoring and consideration of genetic context, may improve recognition of higher-risk phenotypes. Therapeutic strategies must balance arrhythmia control with procedural risk in fragile connective tissue substrates. Conclusions By unifying genetic, mechanistic, and clinical insights, this review provides an integrated framework for understanding arrhythmias in CTDs. It underscores the need for prospective registries and genotype-phenotype studies to refine surveillance and prevention strategies.

ABSTRACT Patients requiring permanent pacing after tricuspid valve intervention present challenges due to the need to cross tricuspid valve prostheses. We report three cases of successful dual coronary sinus (CS) lead implantation for biventricular pacing following a range of tricuspid interventions—surgical tricuspid annuloplasty, transcatheter edge‐to‐edge repair, and transcatheter tricuspid valve replacement. The approach avoided tricuspid valve traversal, was technically feasible and resulted in satisfactory pacing performance without procedural complications. Dual CS lead configurations were individualized based on CS anatomy and pacing characteristics. The degree of QRS narrowing achieved varied according to lead location and ventricular activation patterns, highlighting the importance of individualized lead placement strategies and device programming. Dual CS lead pacing may represent a viable alternative for biventricular pacing in selected patients with prior tricuspid valve interventions. Larger studies are needed to evaluate long‐term outcomes and define the optimal role of this approach among available pacing strategies in this patient population.

Background: Disparities exist in the representation of genders in cardiovascular clinical trials. Atrial fibrillation (AF) is associated with significant morbidity and mortality; however, understanding regarding the representation of women in AF-related clinical trials remains limited. Therefore, this systematic review sought to evaluate the representation of women in AF-related clinical trials. Methods: We conducted a systematic review of clinical trials using the PubMed, Scopus, and EMBASE databases from 1996 to January 1st, 2024, focusing on AF-related lifestyle interventions, pharmacological treatments, catheter ablation, and device therapies for AF. Data extraction and analysis encompassed trial characteristics, participant demographics, and funding sources. The primary outcome was the prevalence of female enrollees, quantified through participation-to-prevalence ratios (PPRs). This was estimated overall and stratified by funding source, intervention type, and enrollment region. Results: Of the 103 clinical trials involving 218,322 participants (39.5% female), the PPR ranged from 0.00 to 1.73, with an average PPR of 1.03. Meanwhile, 43% of the trials exhibited female under-representation (PPR, <0.8). University-funded trials showed higher female enrollment (mean PPR, 0.951) compared to industry/government-funded trials (mean PPR, 0.800). No differences were observed in the representation of women when comparing enrollment regions or intervention types. Conclusions: Despite advancements in AF management, gender disparities persist in AF-related clinical trial representation, particularly in industry/government-funded studies compared to university-funded trials. Thus, addressing implicit biases and enforcing sex equality guidelines are critical steps toward more inclusive cardiovascular research.

Background Immune‐checkpoint inhibitors (ICI) are associated with adverse cardiac events. Although troponin elevation is a diagnostic criterion for ICI‐related myocarditis (ICIrM) and myocardial infarction, data on other causes of troponin elevation and their outcomes in ICI‐treated patients are limited. Methods All patients treated with ICI who had hs‐TnT (high‐sensitivity troponin T) measured at a multicenter institution from 2011 to 2022 were included. Clinical data, outcomes (cardiac death, heart failure (HF), major adverse cardiovascular events [myocardial infarction, stroke, heart failure]), and cause of hs‐TnT elevation were assessed. Risks of cardiac events were compared across hs‐TnT elevation causes. Results Of 5423 patients treated with ICI, 1669 had post‐ICI hs‐TnT measurement (mean age 68.7±11.3 years, 58.3% male), with 1‐year follow‐up. Hs‐TnT elevation in patients with ICIrM (n=59) was associated with the highest risk for cardiac death (hazard ratio [HR], 52.7 [95% CI, 11.7–238.0], P <0.001), followed by hs‐TnT elevation due to heart failure (HR, 15.9), myocardial infarction/type 2 ischemia (HR, 11.6), and infection/sepsis (HR, 5.7), compared with those with no hs‐TnT elevation. ICIrM also carried highest risk for major adverse cardiovascular events (HR, 8.2, [95% CI, 4.4–15.3], P <0.001), followed by myocardial infarction/type 2 ischemia (HR, 8.1), heart failure (HR, 7.6), pulmonary embolus (HR, 5.1), infection/sepsis (HR, 4.1), and indeterminate cause (HR, 2.4). Among ICIrM, HsTnT value >576 ng/L best predicted risk for cardiac death and >319 ng/L for major adverse cardiovascular events. Conclusions Hs‐TnT elevation after ICI therapy is associated with increased risk of cardiac events, particularly in ICIrM, and a graded prognostic association depending on the cause of hs‐TnT elevation. Identifying the underlying cause and troponin thresholds may guide risk stratification and management.

Cardiac amyloidosis (CA) is an underdiagnosed form of infiltrative cardiomyopathy caused by abnormal amyloid fibrils deposited extracellularly in the myocardium and cardiac structures. There can be high variability in its clinical manifestations, and diagnosing CA requires expertise and often thorough evaluation; as such, the diagnosis of CA can be challenging and is often delayed. The application of artificial intelligence (AI) to different diagnostic modalities is rapidly expanding and transforming cardiovascular medicine. Advanced AI methods such as deep-learning convolutional neural networks (CNNs) may enhance the diagnostic process for CA by identifying patients at higher risk and potentially expediting the diagnosis of CA. In this review, we summarize the current state of AI applications to different diagnostic modalities used for the evaluation of CA, including their diagnostic and prognostic potential, and current challenges and limitations.

Background Patients who experience in-hospital ST-segment elevation myocardial infarction (iSTEMI) represent a uniquely high-risk cohort owing to delays in diagnosis, prolonged time to reperfusion and increased mortality. Quality initiatives aimed at improving the care of this vulnerable, yet understudied population are needed. Methods This study included consecutive patients with iSTEMI treated with percutaneous coronary intervention (PCI) between 1 January 2011 and 15 July 2019 at a single, tertiary referral centre. A comprehensive iSTEMI protocol (CSP) was implemented on 15 July 2014, incorporating: (1) cardiology fellow activation of the catheterisation lab using standardised criteria, (2) nursing chest pain protocol, (3) improved electronic access to electrocardiographic studies, (4) checklist for initial triage and management, (5) 24/7/365 catheterisation lab readiness and (6) radial-first PCI approach. Key metrics and clinical outcomes were compared before and after CSP implementation. Results Among 125 total subjects, the post-CSP cohort (n=81) was younger, had more males and were more likely to be hospitalised for cardiac-related reasons relative to the pre-CSP cohort (n=44) who were more likely hospitalised for operative-related aetiologies. After CSP adoption, median ECG-to-first-device-activation time decreased from 113 min to 64 min (p<0.001), goal ECG-to-first-device-activation time increased from 36% to 76% of patients (p<0.001), administration of guideline-directed medical therapy prior to PCI increased from 27.3% to 65.4% (p<0.001), trans-radial access increased from 16% to 70% (p<0.001) and rates of discharge home increased from 56.8% to 76.5% (p=0.04). Statistically insignificant numerical reductions were observed post-CSP in in-hospital mortality (18.2% vs 9.9%, p=0.30), 30-day mortality (15.9% vs 12.3%, p=0.78) and 1-year mortality (27.3% vs 21.0%, p=0.57). Conclusions The implementation of a CSP was associated with marked enhancements in key care metrics among patients with iSTEMI. Among a larger cohort, the use of a CSP yielded a significant reduction in ECG-to-first-device-activation time in a particularly vulnerable population at high risk of death.