Chahal, C. Anwar A.

Abstract Autonomic neural control of the cardiovascular system is formed of complex and dynamic processes able to adjust rapidly to mitigate perturbations in hemodynamics and maintain homeostasis. Alterations in autonomic control feature in the development or progression of a multitude of diseases with wide‐ranging physiological implications given the neural system's responsibility for controlling inotropy, chronotropy, lusitropy, and dromotropy. Imbalances in sympathetic and parasympathetic neural control are also implicated in the development of arrhythmia in several cardiovascular conditions sparking interest in autonomic modulation as a form of treatment. A number of measures of autonomic function have shown prognostic significance in health and in pathological states and have undergone varying degrees of refinement, yet adoption into clinical practice remains extremely limited. The focus of this contemporary narrative review is to summarize the anatomy, physiology, and pathophysiology of the cardiovascular autonomic nervous system and describe the merits and shortfalls of testing modalities available. © 2023 American Physiological Society. Compr Physiol 13:4493‐4511, 2023.

Heart failure with reduced ejection fraction is a major cause of morbidity and mortality. Cardiac resynchronization therapy (CRT) improves outcomes but faces challenges such as unsuccessful lead placement and suboptimal responses. The Wireless Stimulation Endocardially for CRT (WiSE-CRT) system, a novel leadless left ventricular (LV) pacing technology, uses ultrasonic energy to deliver electrical stimulation directly to the LV endocardium, potentially improving the response rates. A comprehensive literature search was performed across multiple databases from inception until August 2024. The outcomes of interest included the New York Heart Association (NYHA) functional score, LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and QRS duration. Statistical analysis involved pooling the mean differences (MDs) and their corresponding 95% confidence intervals (CIs) from each study using the inverse-variance random-effects model in RevMan version 5.4.1 software. Seven studies, including 468 patients with heart failure treated with the WiSE-CRT system, were included. The pooled analysis showed significant improvements in NYHA functional score (MD: −0.44; 95% CI: −0.67 to −0.21; P = 0.0002; I 2 = 77%), LVEF (MD: 5.71; 95% CI: 4.54 to 6.87; P < 0.001), LVEDV (MD: −24.49; 95% CI: −33.24 to −15.73; P < 0.001), and LVESV (MD: −24.47; 95% CI: −32.80 to −16.14; P < 0.001). The QRS duration also decreased significantly (MD: −38.62; 95% CI: −46.76 to −30.49; P < 0.001; I 2 = 60%). The WiSE-CRT system significantly improved NYHA functional score, LVEF, QRS duration, LVEDV, and LVESV in patients with heart failure. This leadless pacing technology offers a promising alternative for ineligible candidates or for those who do not respond to conventional CRT.

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity worldwide. Low-dose colchicine is a novel and nonstandard management approach for patients with CVDs who are at an increased risk of adverse events. However, few studies have reported the risk of stroke with colchicine, with controversial results. This meta-analysis aimed to compare the efficacy of colchicine and placebo for stroke prevention in patients with CVD. Major electronic databases were screened for randomized controlled trials (RCTs) comparing colchicine and placebo in patients with CVDs from inception to June 2024. Pooled estimates were calculated as risk ratios (RRs) with 95% confidence intervals (CIs) using an inverse-variance random-effects model. Statistical significance was set at P < 0.05. A total of 15 RCTs encompassing 25,116 patients with CVDs were included (12,568: colchicine and 12,548: placebo). The pooled analysis demonstrated a significant reduction in stroke [RR, 0.80 (95% CI, 0.64–0.99); P = 0.04] with colchicine compared with placebo. The risk of all-cause mortality [RR, 1.00 (95% CI, 0.77–1.28)] was comparable between the 2 groups. On subgroup analysis, low-dose colchicine (0.5 mg/day) demonstrated a significantly lower risk of stroke compared with high-dose (>0.5 mg/day) colchicine, which failed to achieve statistical significance. Based on this meta-analysis, colchicine significantly reduced stroke in patients with CVDs compared with placebo. This effect was most significant with low-dose colchicine at 0.5 mg/day. However, no differences were observed in all-cause mortality. Further long-term RCTs are warranted to investigate stroke prevention using colchicine in this population.

Abstract Aims In light of recent advances in imaging techniques, molecular understanding and therapeutic options in hypertrophic cardiomyopathy (HCM), we performed a systematic review of current guidelines for the diagnosis and management of HCM in order to identify consensus and discrepant areas in the clinical practice guidelines. Methods and results We systematically reviewed the English language guidelines and recommendations for the management of HCM in adults. MEDLINE and EMBASE databases were searched for guidelines published in the last 10 years. Following a systematic search, three guidelines on the diagnosis and management of HCM were identified, all of which were robustly developed (AGREE rigour of development score ≥50%). These guidelines were authored by the major European (European Society of Cardiology; 2023), American (American Heart Association /American College of Cardiology/American Medical Society for Sports Medicine /Heart Rhythm Society/Pediatric and Congenital Electrophysiology Society/Society for Cardiovascular Magnetic Resonance; 2024), and Japanese [Japanese Circulation Society (JCS)/Japanese Heart Failure Society (JHFS); 2018] cardiovascular societies. There was broad consensus on echocardiographic recommendations, the medical and invasive management of HCM, the application of genetic testing and family screening, and exercise and reproductive recommendations in HCM. There were areas of variability in the definition and diagnostic criteria for HCM, cardiovascular magnetic resonance imaging recommendations, and assessment of sudden cardiac death (SCD) risk and prevention strategies. Due to the JCS/JHFS guidelines being older, there are no recommendations on the use of cardiac myosin ATPase inhibitors. Conclusion Contemporary guidelines for HCM achieve consensus across a broad range of criteria and recommendations concerning diagnosis and management. However, variations in the approach towards risk assessment for SCD exist between the guidelines. There are also more subtle differences concerning diagnostic criteria and the utility of late gadolinium enhancement for risk stratification, which will likely evolve as the evidence-base broadens.

Abstract Aims Causes of death remain largely unexplored in the atrial fibrillation (AF) population. We aimed to (i) thoroughly assess causes of death in patients with AF, especially those associated with sudden cardiac death (SCD) and (ii) evaluate the potential association between AF and SCD. Methods and results Linked primary and secondary care United Kingdom Clinical Practice Research Datalink dataset comprising 6 529 382 individuals aged ≥18. We identified 214 222 patients with newly diagnosed AF, and an equivalent number of non-AF patients matched for age, sex and primary care practice. The underlying primary cause of death for each patient was assessed in the form of International Classification of Diseases Tenth Revision (ICD-10) codes and also as part of broader disease categories (i.e. ICD-10 chapters). Findings Over a median follow-up of 2.7 (interquartile range: 0.7–6.0) years, 124 781 (58.25%) patients with AF died. Sudden cardiac death occurred in 13 923 patients with AF [6.50% patients with AF vs. 2.01% non-AF patients; odds ratio (OR) = 3.38, 95% confidence interval (CI): 3.27–3.50, P &lt; 0.0001], contributing to 11.05% of all AF mortality. Diseases of the circulatory system, neoplasms and respiratory diseases explained 45% of AF mortality. Sudden cardiac death occurred more frequently in males (OR = 1.87, 95% CI: 1.80–1.93, P &lt; 0.0001), and females with AF died more often of diseases of the circulatory, respiratory, digestive, and genitourinary system and less often of neoplastic disorders. Interpretation Conditions of the circulatory system are the main driver of mortality in the AF population. Females with AF experience higher cardiovascular and respiratory mortality but die less frequently of neoplasms. The risk of SCD is higher in the AF population, occurring more frequently in males.

Background and Objectives: The epidemiological data regarding mortality rates of adults with sarcoidosis and non-ischemic cardiovascular disease (CVD) are limited. A retrospective observational analysis was conducted to identify trends and disparities related to sarcoidosis and non-ischemic cardiovascular disease mortality among the adult US population from 1999 to 2022. Methods: We used the Centers for Disease Control and Prevention (CDC) WONDER database to extract death certificate data for the adult US population (≥25 years). The age-adjusted mortality rates (AAMRs) per 100,000 persons were calculated, and annual percent changes (APCs) were determined using Joinpoint. Results: Between 1999 and 2022, 23,642 deaths were identified related to non-ischemic CVD + sarcoidosis. The overall AAMR increased from 0.2 (95% CI, 0.2 to 0.3) in 1999 to 0.5 (95% CI, 0.5 to 0.6) in 2022. Females had a higher AAMR than males (0.6 vs. 0.5). Non-Hispanic (NH) blacks had the highest AAMR, followed by NH whites and Hispanic or Latinos. The southern region had the highest AAMR (0.7: 95% CI, 0.6–0.7), followed by the Midwest (0.6, 95% CI, 0.54–0.669), the Northeast (0.5, 95% CI, 0.5 to 0.6), and the West (0.4; 95% CI, 0.3–0.4). Urban and rural areas had comparable mortality rates (0.5 vs. 0.6). People aged 65+ had the highest AAMRs. Conclusions: The overall mortality rates for non-ischemic CVD and sarcoidosis have increased in the US from 1999 to 2022. Females and NH blacks had higher AAMRs, while a minimal variation was observed based on geographical regions. Early diagnosis and prompt management are the keys to reducing the mortality burden of non-ischemic CVD plus sarcoidosis.

Background: Mitral valve prolapse (MVP) is a common valvular abnormality. Observational studies demonstrate an association between MVP and increased risk of sudden cardiac death from ventricular arrhythmias, coined arrhythmogenic MVP. A genetic component has been postulated but remains under-investigated. Hypothesis: Predicted deleterious variants in Mendelian cardiomyopathy and arrhythmia genes are more frequent in arrhythmogenic MVP (aMVP) compared to non-arrhythmogenic MVP. Aims: To comprehensively phenotype and genotype a single-center aMVP cohort and compare to non-aMVP from two large population-based cohorts and investigate their clinical outcomes. Methods: The aMVP cohort included 46 prospectively enrolled patients from a regional referral center for inherited cardiovascular disease and had undergone multi-modality imaging and clinical gene panel testing. The non-aMVP comparator cohorts included 453 participants from the UK Biobank (UKBB), a prospective cohort of 500,000 UK residents, and 1,418 participants from the National Institutes of Health (NIH) All of Us (AoU), a prospective cohort of 450,000 USA participants. Gene variants were annotated in ANNOVAR. Participants with and without pathogenic/likely pathogenic (P/LP) variants reported on ClinVar with ≥2-star level of evidence were considered genotype positive (G+) and negative (G-) respectively. Results: The demographics for aMVP (age 61.2 ± 12.8 years, 56.5% female) and non-aMVP (UKBB: age 59.8 ± 7.3 years, 50.7% female and AoU: age 65.3 ± 13.4 years, 76.2% female) were comparable. G+ participants were more prevalent in the aMVP cohort 10/46 (21.7%) versus non-aMVP in the UKBB 8/453 (1.8%) and in the AoU 21/1418 (1.5%); p<0.001. The most frequently implicated gene in aMVP was TTN . Of 46 in aMVP cohort, 33 (71%) underwent CMR. G+ participants had a higher frequency of late gadolinium enhancement [6/6 (100%) vs. 14/27 (51.8%), p<0.001] and wall motion abnormalities [3/6 (50%) vs. 1/27 (3.7%), p<0.001] compared to G- participants. The aMVP cohort had significantly more implantable cardioverter defibrillator (ICD) implants compared to non-aMVP cohort [5/46 (10.9%) vs. 1/453 in UKBB (0.2%), p<0.001]. G+ aMVP cohort showed a trend for developing heart failure and ICD implants compared to G- aMVP . Conclusion: P/LP variants in cardiomyopathy and arrhythmia genes are more prevalent in aMVP participants compared to non-aMVP participants. This could be a hitherto unrecognized effect modifier predicting aMVP .

Background: Sleep disordered breathing (SDB) is frequently observed in patients with cardiovascular disease, and is associated with intermittent hypoxia, sympathetic activation, oxidative stress, and endothelial dysfunction, all of which may facilitate the development and progression of cardiovascular disease. Objectives: We sought to determine the prevalence, subtypes, and clinical implications of comorbid SDB in patients with hypertrophic cardiomyopathy (HCM). Methods: In this prospective observational study, patients with HCM without prior diagnosis of SDB were recruited to undergo inpatient polysomnography between May 1 st 2018 and October 31 st 2022. Electrocardiographic and echocardiographic parameters, cardiac biomarkers, and symptoms were comparatively assessed in patients with and without comorbid SDB. Patients were assessed for the development of major adverse cardiovascular events (MACE) during follow-up (median 29, range 3-57 months). Results Among 154 participants, 91 (59.1%) were diagnosed with SDB of whom 38 (41.8%) had mild, 22 (24.2%) moderate, 18 (19.8%) severe obstructive sleep apnea, and 13 (14.3%) had central sleep apnea. SDB was associated with greater left ventricular mass (median [IQR]) (128 [107, 161] vs. 109 [96, 134] g/m 2 , p =0.034) and E/e’ ratio (12.5 [10, 15] vs. 10.0 [8.3, 14.5], p =0.039). Patients with HCM over the age of 50 years, with body mass index ≥ 30kg/m 2 , who described their sleep as “poor” were at particularly high risk of having comorbid SDB, as were those who were diabetic, hypertensive, or described greater exertional limitation (NYHA Class ≥II 53% vs. 27%, p =0.005). Importantly, subjects with SDB had elevated baseline Troponin T levels (14 ng/L vs 11 ng/L, p =0.030), and further substantial overnight troponin increases following untreated apneic sleep (2.1ng/L vs 0.2ng/L, p =0.009). Finally, patients with comorbid SDB experienced a significantly higher proportion of incident adverse cardiovascular events (MACE hazard ratio 5.3, 95% CI, 1.6, 17.2, p =0.006) than those without SDB. Conclusions: We report a particularly high burden of previously undiagnosed SDB in patients with HCM, particularly in older, heavier, male patients. Undiagnosed SDB in HCM is not benign and is associated with symptom progression, comorbidity, and a poorer prognosis, particularly in the case of central sleep apnea. These important new findings provide rationale for heightened vigilance and routine screening for SDB in patients with HCM.

Background Hyperlipidemia is a major cardiovascular disease (CVD) risk factor, but there are limited data on its mortality trends in CVD over time. We assessed annual hyperlipidemia‐related CVD mortality trends in the United States, including the COVID‐19 pandemic's impact. Methods and Results Mortality data were obtained from the Centers for Disease Control and Prevention repository between 1999 and 2020 among patients ≥15 years old, using International Classification of Diseases, Tenth Revision ( ICD‐10 ) codes for hyperlipidemia (E78.0–E78.5) and CVD (I00–I99). Age‐adjusted mortality rates (AAMRs) per 1 000 000 population were standardized to the 2000 US population. Log‐linear regression models were used to evaluate mortality shifts. Average annual percentage change from 1999 to 2019 was used to project 2020 AAMRs, estimating pandemic‐attributed excess deaths. From 1999 to 2020, 483 155 hyperlipidemia‐related CVD deaths occurred. Despite a general CVD mortality decline, hyperlipidemia‐related CVD AAMRs rose from 36.33 in 1999 to 99.77 in 2019. Ischemic heart diseases (AAMR 49.39) were the leading cause, whereas hypertension had the highest mortality increase (average annual percentage change +10.23%). Mortality rates were higher in men (AAMR 104.87) and non‐Hispanic (AAMR 82.49), and rural populations (AAMR 89.98). Highest mortality was observed in Black populations (AAMR 84.35), those ≥75 years old (AAMR 646.45), and Western US regions (AAMR 96.88). During the first pandemic year, deaths exceeded projections by 10.55%, with notable increases among ages 35 to 75 (14.23%), Hispanic (17.96%), Black (14.82%), and urban (11.68%) groups. Conclusions Hyperlipidemia‐related CVD mortality has risen over the past 2 decades, further heightened by the COVID‐19 pandemic, with higher impact on men, Black Americans, the older population, and rural residents. Further study is needed to understand contributing factors and mitigate disparities.

Precision medicine, which among other aspects includes an individual's genomic data in diagnosis and management, has become the standard‐of‐care for Mendelian cardiovascular disease (CVD). However, early identification and management of asymptomatic patients with potentially lethal and manageable Mendelian CVD through screening, which is the promise of precision health, remains an unsolved challenge. The reduced costs of genomic sequencing have enabled the creation of biobanks containing in‐depth genetic and health information, which have facilitated the understanding of genetic variation, penetrance, and expressivity, moving us closer to the genotype‐first screening of asymptomatic individuals for Mendelian CVD. This approach could transform health care by diagnostic refinement and facilitating prevention or therapeutic interventions. Yet, potential benefits must be weighed against the potential risks, which include evolving variant pathogenicity assertion or identification of variants with low disease penetrance; costly, stressful, and inappropriate diagnostic evaluations; negative psychological impact; disqualification for employment or of competitive sports; and denial of insurance. Furthermore, the natural history of Mendelian CVD is often unpredictable, making identification of those who will benefit from preventive measures a priority. Currently, there is insufficient evidence that population‐based genetic screening for Mendelian CVD can reduce adverse outcomes at a reasonable cost to an extent that outweighs the harms of true‐positive and false‐positive results. Besides technical, clinical, and financial burdens, ethical and legal aspects pose unprecedented challenges. This review highlights key developments in the field of genotype‐first approaches to Mendelian CVD and summarizes challenges with potential solutions that can pave the way for implementing this approach for clinical care.