Atrial fibrillation in hypertrophic cardiomyopathy-a contemporary mini review

First-degree atrioventricular block in hypertrophic cardiomyopathy patients: an easy and worthy prognostic marker?

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. Recently, a connection has been observed between the presence of first-degree atrioventricular block (FDAVB) and cardiovascular outcomes, although the pathophysiology of this association remains poorly understood. Considering the period 2000-2023, we retrospectively included HCM patients at sinus rhythm at the first appointment and sought possible interactions of FDAVB (defined as PR interval >200 ms) with different clinical and imaging variables and with the occurrence of cardiovascular events, including atrial fibrillation (AF). A total of 97 patients were included, of whom 57 (58.8%) were men, with a mean age of 51±19 years, and 14 (14.4%) had FDAVB. During a median of 4.29 (P25 1.92, P75 7.67) years of follow-up, 35 cardiovascular events occurred, including 13 de novo diagnoses of AF, 8 hospitalizations due to heart failure, 8 new-onset strokes, 4 myocardial infarctions, and 2 implantations of cardio defibrillators in secondary prevention; no HCM-related death occurred. We did not find any association between outcomes and the presence of FDAVB. The role of FDAVB as a prognostic marker in HCM patients requires further investigation. We found that FDAVB patients were older, more frequently reported dyspnea, had a larger QRS duration, a higher E/e' ratio, and lower maximal left ventricle wall thickness by magnetic resonance (p<0.05). After multivariable analysis, FDAVB was independently associated with a higher echocardiographic E/e' ratio (p=0.039) (odds ratio=1.588). This is the first paper to document an independent association between FGAVB and a higher E/e' ratio in HCM patients.

Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy and Cardiac Amyloidosis: From Clinical Management to Catheter Ablation Indication

Atrial fibrillation (AF) is the most common arrhythmia in patients affected by cardiomyopathies. Reports estimate a prevalence of 27% in patients with hypertrophic cardiomyopathy (HCM) and 40% in patients with cardiac amyloidosis (CA). The presence of AF typically results in progressive functional decline, an increased frequency of hospitalizations for heart failure, and a higher thromboembolic risk. Medical management using mainly beta-blockers or amiodarone has produced variable outcomes and a high rate of recurrence. Catheter ablation reduces symptom burden and complications despite a moderate rate of recurrence. Recent evidence suggests that an early rhythm control strategy may lead to more favorable short- and long-term outcomes. In this review, we summarize contemporary data on the management of AF in patients with cardiomyopathy (HCM and CA) with particular reference to the timing and outcomes of ablation procedures.

The causal effects of genetically determined human blood metabolites on the risk of atrial fibrillation

Background

Blood metabolites have been found related to atrial fibrillation (AF), but the causal role is still unclear. Mendel randomization (MR) can give information about the causality between blood metabolites and AF.

Methods

Two-sample MR analysis was used to evaluate the causality between 486 blood metabolites and AF. Firstly, the genome-wide association study (GWAS) data for AF (from Nielsen et al.) was analyzed and some metabolites were identified. Then another GWAS data for AF (from Roselli et al.) was repeatedly analyzed to verify the results. Inverse variance weighted method was mainly used to determine the causality, and MR-egger, Weighted Median, and MR-PRESSO models were used as supplements of MR. Cochran's Q test was used to assess heterogeneity. And MR-Egger intercept and MR-PRESSO global test were performed to measure pleiotropy.

Results

The study used Bonferroni's corrected P value (P < 1.03 × 10-4) as the significance threshold. After MR analysis and replication analysis, we found two overlapped metabolites. Among which tryptophan betaine was the most significant causal metabolite in both AF GWAS data (from Nielsen et al.) (odds ratio (OR) = 0.83, 95% confidence interval (CI) = 0.76-0.90, P = 9.37 × 10-6) and AF GWAS data (from Roselli et al.) (OR = 0.82, 95% CI = 0.76-0.88, P = 2.00 × 10-7), while uridine was nominally significant metabolites in both AF GWAS data (from Nielsen et al.) (OR = 0.58, 95% CI = 0.40-0.84, P = 0.004) and AF GWAS data (from Roselli et al.) (OR = 0.56, 95% CI = 0.35-0.88, P = 0.01). And the results of sensitivity analysis showed that none of them had obvious heterogeneity or pleiotropy.

Conclusion

The study identified several blood metabolites that were causally related to AF, which may provide new perspectives on the pathogenesis of AF.

Clinical Application of the HCM-AF Risk Score in the Prediction of Clinical Outcomes of Polish Patients with Hypertrophic Cardiomyopathy

The recently introduced HCM-AF Risk Calculator allows the prognosis of atrial fibrillation (AF) occurrence in hypertrophic cardiomyopathy (HCM) patients. The aim of this study was to assess the clinical application of the HCM-AF Risk Score in the prediction of the clinical outcomes of Polish patients. The study included 92 patients (50.0% female, median age 55 years), with a baseline sinus rhythm diagnosed between 2013 and 2018. The analysis involved the incidence of clinical characteristics and outcomes, total mortality, rehospitalisation, and the course of heart failure (HF). According to the HCM-AF Risk Score, the HCM population was stratified into three subgroups, with a low (13/14.2%), intermediate (30/32.6%), and high risk of AF (49/53.2%). Subgroups differed significantly: the high-risk subgroup was older, had a higher body mass index (BMI), and more advanced signs of left ventricular (LV) hypertrophy and left atrium (LA) dilatation. The registered AF incidence was 31.5% and 43.5% in the 2- and 5-year follow-ups, and it was significantly higher than in the HCM-AF Risk Score population, which had 4.6% in the 2-year follow-up, and 10.7% in the 5-year follow-up. In the whole population, the AF incidence in both the 2- and 5-year follow-ups revealed a strong correlation with the HCM-AF Risk Score (r = 0.442, p < 0.001; r = 0.346, p < 0.001, respectively). The clinical outcomes differed among the subgroups: the total mortality was 15.4% vs. 20.0% vs. 42.9% (p < 0.05); rehospitalisation was 23.1% vs. 53.3% vs. 71.4% (p < 0.05). The highest HF progression was in the high-risk subgroup (36.7%). Regardless of the high results of the HCM-Risk Score in Polish patients, the score underestimates the real-life high level of AF incidence. The HCM-AF Risk Score seems to be useful in the prediction of the general clinical outcomes in HCM patients.

[The levels of certain circulating microRNAs in hypertrophic cardiomyopathy are associated with echocardiographic parameters]

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease; it is characterized by left ventricular (LV) hypertrophy that cannot be explained by hemodynamic causes. It is believed that sarcomere dysfunction underlies the pathogenesis of this disease, however, only half of patients with the HCM phenotype have mutations in sarcomere-encoding genes. HCM is distinguished by both high genetic and clinical heterogeneity and therefore more studies are seeking to investigate a regulation of gene expression in HCM and how the abnormalities in this process can affect disease phenotype. One of the levels of regulation of gene expression - a post-transcriptional level - is mediated by short non-coding microRNAs that inhibit protein synthesis.

AIM

To identify the correlations between levels of circulating microRNAs, previously shown to be associated with HCM, and clinical parameters of HCM patients.

MATERIALS AND METHODS

Correlation analysis of miR-499a-5p, miR-454 and miR-339-5p plasma levels and clinical parameters of 33 HCM patients, examined from 2019 to 2021, has been performed.

RESULTS

Variants in HCM-associated genes were found in 49% of patients. There were no clinical differences between genotype-positive and genotype-negative patients. MiR-499a-5p level correlated with LV ejection fraction, miR-454 level - with LV diastolic function parameters and miR-339-5p level - with left atrium dimension.

CONCLUSION

Levels of certain circulating microRNAs correlate with echocardiographic parameters in HCM patients.

Atrial cardiomyopathy: Diagnosis, clinical implications and unresolved issues in anticoagulation therapy

Atrial cardiomyopathy (AC) is an evolving pathophysiological entity that has expanded our understanding regarding the atrium and its role in arrhythmogenesis and cardiac thromboembolism. The pathological myocardium in AC promotes arrhythmogenesis through mechanical dysfunction (hypocontractility, fibrosis), adverse alterations of the endothelium and secretion of prothrombotic factors (IL-6, IL-8, TNF-a). 'Red flags', indicative of AC, can be recognized either non-invasively by electrocardiography, echocardiography and cardiac magnetic resonance imaging or invasively by high-density electroanatomical mapping as low bipolar voltage areas of the affected myocardium. Signs of AC have been strongly associated with an increased risk of ischemic stroke, even embolic strokes of undetermined source, regardless of the coexistence of atrial fibrillation (AF). The underlying existence of AC has been negatively correlated with the success rate of catheter ablation of AF. The clinical value of AC is the provision of a novel pathway regarding the potential mechanisms of cerebrovascular events of cardiac thromboembolic origin. In addition, AC may serve as a risk stratification tool to predict the long-term responders of AF catheter ablation.

Twenty-four hour variability of inverted T-waves in patients with apical hypertrophic cardiomyopathy

Background

Patients with apical hypertrophic cardiomyopathy (ApHCM) have marked inverted T-waves that vary over several years. Inverted T-waves in ApHCM are unstable, but it is unclear whether this change is due to coronary artery disease (CAD) or if it is a characteristic of ApHCM itself. We aimed to study the characteristics of inverted T-waves in patients with ApHCM over the course of 24 h to improve the diagnostic indices of ApHCM.

Methods

We examined 83 patients with ApHCM and 89 patients with CAD (who served as the control group). All patients underwent a 24-h dynamic electrocardiogram (ECG). We analyzed the average depth of inverted T-waves per minute and sorted them from shallow to deep; the sorted ECG segments at the 10^th, 50^th, and 90^th positions of the T-wave were subsequently analyzed.

Results

The amplitudes of inverted T-waves in ApHCM corresponding to the 10^th, 50^th, and 90^th percentiles were −5.13 ± 4.11, −8.10 ± 4.55, and −10.9 ± 5.04 mm, respectively. Changes in the degree of inverted T-waves were greater in ApHCM than in CAD. T-wave amplitudes in ApHCM were strongly associated with heart rate and circadian rhythm and only weakly associated with CAD and posture. Maximum T-wave amplitudes in the CAD group were <10 mm, while 68% of patients with ApHCM had maximum T-wave amplitudes >10 mm, and all patients with ApHCM aged <50 years had maximum T-wave amplitudes >10 mm.

Conclusion

Notable variations in the T-waves of patients with ApHCM were observed over 24 h. ECG examinations during states of inactivity (comparable to sleep) improved the sensitivity of the diagnosis of ApHCM. Inverted T-wave amplitudes correlated with heart rate and circadian rhythm, where T-wave changes in ApHCM may be due to the normalization of abnormal T-waves effect. Identifying T-wave amplitudes >10 mm can effectively improve the diagnostic rate of ApHCM, especially in patients aged <50 years. The short-term change in T-waves in patients with ApHCM could serve as a novel index that will help in the diagnosis of ApHCM.

Effect of Perioperative Comprehensive Nursing Intervention on the Rehabilitation Effect of Radiofrequency Ablation for Patients with Hypertrophic Obstructive Cardiomyopathy

Objective

The aim of the study was to determine standardized perioperative nursing for radiofrequency ablation of hypertrophic obstructive cardiomyopathy under the guidance of intracardiac ultrasound, which can improve the quality of nursing.

Methods

From January 2020 to November 2021, 40 patients with hypertrophic obstructive cardiomyopathy who underwent radiofrequency ablation under the guidance of intracardiac ultrasound in our hospital were selected. Patients were grouped according to their use of standardized perioperative nursing. Patients from both cohorts were compared for negative emotions, depression, and anxiety at the baseline and at month 2.

Results

In general, there were no differences between the two groups (P > 0.05). At admission, the Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale (SAS) scores of these two groups showed no differences (P > 0.05). Following nursing, the scores of the two groups dropped significantly, with the control group scoring much lower than the experimental group. Among the experimental group, the satisfaction rate was 100.00%, whereas the control group had an 85.00% satisfaction rate (P < 0.05). Following nursing, the scores of the two groups dropped significantly, with the control group scoring much lower than the experimental group.

Conclusions

To sum up, perioperative comprehensive nursing intervention during surgical treatment can quickly alleviate patients' clinical symptoms, reduce complications, damage to patients' body, reduce patients' pain, relieve patients' anxiety and depression, and improve overall sleep quality and clinical nursing satisfaction.