Clinical impact of atrial fibrillation in a nationwide cohort of hypertrophic cardiomyopathy patients

Distinct Phenotypic Groups and Related Clinical Outcomes in Patients With Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a heterogeneous disorder with varying risks of clinical outcomes, including sudden cardiac death (SCD). We aimed to identify distinct phenotypes among patients with HCM in relation to SCD risk factors, interpret their clinical characteristics, and examine their outcomes.

METHODS AND RESULTS

This retrospective study analyzed 1231 consecutive patients with HCM from 2 tertiary hospitals. We performed latent class analysis to categorize patients into phenotypic groups. Three distinct phenotypic groups were identified using latent class analysis. Group 1 (n=554) consisted of young patients with HCM with minimal SCD risk factors and favorable cardiac remodeling. Group 2 (n=114) comprised young patients with HCM and a high prevalence of SCD risk factors, whereas Group 3 (n=563) included older patients (median age, 68 years). Over a median 6.5-year follow-up, 34 SCD-related events, 131 cardiovascular events, 133 all-cause mortality events, and 70 noncardiovascular mortality events were observed. Group 2 exhibited the highest rate of SCD-related events (5-year SCD rate: Group 1 versus 2 versus 3: 0.8% versus 8.2% versus 4.0%, respectively, P<0.001), and cardiovascular events were more frequent in Groups 2 and 3 compared with Group 1. All-cause and noncardiovascular mortality were the most frequent in Group 3. A simplified decision tree was developed for the straightforward assignment of phenotypic group membership, demonstrating fair concordance.

CONCLUSIONS

This study identified 3 distinct clinical phenotypes in patients with HCM, each associated with different SCD risks and outcomes. Data-driven phenotyping of patients with HCM offers effective risk stratification and may optimize patient management.

Understanding the incidence of atrial fibrillation and stroke in hypertrophic cardiomyopathy patients: insights from Danish nationwide registries

AIMS

The treatment of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) can be challenging since AF aggravates symptoms and increases the risk of stroke. Which factors contribute to the development of AF and stroke in HCM remains unknown. The aim of this study was to determine the incidence of AF and stroke in HCM patients and identify the risk factors.

METHODS AND RESULTS

Using Danish national registries, all HCM patients from 2005 to 2018 were included. The association between HCM, incident AF, and stroke was investigated using multivariable Cox proportional hazards analysis. Cumulative incidences were calculated using the Aalen-Johansen estimator. Among the 3367 patients without prevalent AF, 24% reached the endpoint of incident AF with death as a competing risk. Median follow-up time was 4 years. Atrial fibrillation incidence was equal between sexes and increased for patients with ischaemic heart disease [IHD; hazard ratio (HR) 1.33, 95% confidence interval (CI) 1.08-1.63], hypertension (HT) (HR 1.36, 95% CI 1.14-1.67), and obstructive HCM (HR 1.27, 95% CI 1.05-1.52). Seven per cent developed stroke, with no difference detected stratifying for the presence of AF. Sub-analysis revealed that when AF was treated with oral anticoagulants (OACs), stroke was less likely (HR 0.4, 95% CI 0.18-0.86, P = 0.02). However, 34% of patients were not receiving adequate anticoagulation following AF diagnosis.

CONCLUSION

Obstructive HCM, HT, and IHD were associated with increased risk of AF. Prevalent AF alone was not predictive of stroke; however, AF patients treated with OAC were significantly less likely to develop stroke, suggesting that this development is driven by the protective effect of OAC. Despite this, 34% of patients did not receive OAC.

Machine Learning-Based Discrimination of Cardiovascular Outcomes in Patients With Hypertrophic Cardiomyopathy

Background

Current risk stratification strategies for patients with hypertrophic cardiomyopathy (HCM) are limited to traditional methodologies.

Objectives

The authors aimed to establish machine learning (ML)-based models to discriminate major cardiovascular events in patients with HCM.

Methods

We enrolled consecutive HCM patients from 2 tertiary referral centers and used 25 clinical and echocardiographic features to discriminate major adverse cardiovascular events (MACE), including all-cause death, admission for heart failure (HF-adm), and stroke. The best model was selected for each outcome using the area under the receiver operating characteristic curve (AUROC) with 20-fold cross-validation. After testing in the external validation cohort, the relative importance of features in discriminating each outcome was determined using the SHapley Additive exPlanations (SHAP) method.

Results

In total, 2,111 patients with HCM (age 61.4 ± 13.6 years; 67.6% men) were analyzed. During the median 4.0 years of follow-up, MACE occurred in 341 patients (16.2%). Among the 4 ML models, the logistic regression model achieved the best AUROC of 0.800 (95% CI: 0.760-0.841) for MACE, 0.789 (95% CI: 0.736-0.841) for all-cause death, 0.798 (95% CI: 0.736-0.860) for HF-adm, and 0.807 (95% CI: 0.754-0.859) for stroke. The discriminant ability of the logistic regression model remained excellent when applied to the external validation cohort for MACE (AUROC = 0.768), all-cause death (AUROC = 0.750), and HF-adm (AUROC = 0.806). The SHAP analysis identified left atrial diameter and hypertension as important variables for all outcomes of interest.

Conclusions

The proposed ML models incorporating various phenotypes from patients with HCM accurately discriminated adverse cardiovascular events and provided variables with high importance for each outcome.

Prognostic effect of atrial fibrillation on survival in patients with hypertrophic cardiomyopathy: a meta-analysis

OBJECTIVE

To systematically evaluate the prognostic impact of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM).

METHODS

The Chinese and English databases (PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure, and Wanfang database were systematically searched to include observational studies on the prognosis of AF in cardiovascular events or death in patients with HCM; these were evaluated using Revman 5.3.

RESULTS

After systematic search and screening, a total of 11 studies with a high study quality were included in this study. Meta-analysis showed that patients with HCM accompanied by AF had a higher risk of all-cause death (odds ratio [OR] = 2.75; 95% confidence interval [CI]: 2.18-3.47; P < 0.001), heart-related death (OR = 2.62; 95%CI: 2.02-3.40; P < 0.001), sudden cardiac death (OR = 7.09; 95%CI: 5.77-8.70; P < 0.001), heart-failure-related death (OR = 2.04; 95%CI: 1.24-3.36; P = 0.005), and stroke death (OR = 17.05; 95%CI: 6.99-41.58; P < 0.001) compared with patients with HCM without AF.

CONCLUSION

Atrial fibrillation is a risk factor for adverse survival outcomes in patients with HCM, and aggressive interventions are needed in this population to avoid the occurrence of adverse outcomes.

Impact of coronary artery revascularization on long-term outcome in hypertrophic cardiomyopathy patients: a nationwide population-based cohort study

Limited data are available on the long-term outcomes in patients with hypertrophic cardiomyopathy (HCM) patients with significant coronary artery disease (CAD) requiring revascularization. We investigated the risk of cardiovascular outcomes in HCM patients who underwent coronary revascularization compared to the control group without HCM. HCM patients aged ≥ 20 years were enrolled from the Korean National Health Insurance Database. Information on the diagnosis and previous medical history was obtained from the claims data. Cardiovascular outcomes were identified during 8-year after coronary revascularization in HCM patients (HCM group) and matched controls without HCM (non-HCM control group). A total of 431 patients in the HCM group and 1968 in the non-HCM control group were analyzed. The risk of all-cause death, cardiovascular death, sudden cardiac death (SCD), ischemic stroke, and hospitalization due to heart failure was significantly higher in the HCM group than in the non-HCM group, with prominent risk increase of cardiovascular death (adjusted hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.63-3.15, P < 0.001) and ischemic stroke (adjusted HR 2.38, 95% CI 1.55-3.64, P < 0.001). Beyond 1-year after revascularization, the HCM group still had a significantly higher risk of cardiovascular death, SCD, and ventricular fibrillation/tachycardia compared to the non-HCM group. Mortality and major cardiovascular outcomes occurred more frequently in HCM patients with significant CAD requiring revascularization, compared to the matched non-HCM control group. Active and regular surveillance for concomitant risk factors and relevant intervention are warranted in HCM patients at increased risk for CAD.

Ischaemic events in hypertrophic cardiomyopathy patients with and without atrial fibrillation: a systematic review and meta-analysis

Hypertrophic cardiomyopathy predisposes to acute cerebrovascular events including ischaemic stroke, transient ischaemic attack and systemic thromboembolism. Atrial fibrillation confers even higher risk. We aim to report the incidence of these complications and to investigate the impact of atrial fibrillation on the ischaemic risk in patients with hypertrophic cardiomyopathy. A literature search was performed on PubMed, Scopus, Embase/Ovid and Cochrane library from inception to 20th March 2021. We compared the incidence of ischaemic strokes, transient ischaemic attack, non-specified thromboembolism events and systemic thromboembolism in hypertrophic cardiomyopathy patients with or without atrial fibrillation. Non-specified thromboembolism events in our paper referred to thromboembolic events whereby types were not specified in the studies. Meta-analysis was performed using StataSE 16 software, and heterogeneity was assessed using I² test. A total of 713 studies were identified. Thirty-five articles with 42,570 patients were included. The pooled incidence of stroke/ transient ischaemic attack was 7.45% (95% confidence interval [CI] 5.80-9.52, p < 0.001) across 24 studies with a total of 37,643 hypertrophic cardiomyopathy patients. Atrial fibrillation significantly increased the risk of total stroke/ transient ischaemic attack (Risk Ratio 3.26, 95% CI 1.75-6.08, p < 0.001, I² = 76.0). The incidence of stroke/ transient ischaemic attack was 9.30% (95% CI 6.64-12.87, p = 0.316) in the apical hypertrophic cardiomyopathy subgroup. Concomitant atrial fibrillation in hypertrophic cardiomyopathy increases the risk of thromboembolic events including ischaemic stroke and transient ischaemic attack. The apical subgroup shows a similar risk of acute cerebrovascular events as the overall hypertrophic cardiomyopathy population.

Application of the ALBI Scoring System for Mortality Outcome Prediction in Patients with Hypertrophic Cardiomyopathy

Background:

There is no information about the clinical significance of the albumin-bilirubin (ALBI) score in patients with hypertrophic cardiomyopathy (HCM).

Objective:

We retrospectively performed clinical evaluations in 462 patients with HCM to estimate whether the ALBI score could be a new tool to predict mortality in HCM.

Methods and Results:

During a median follow-up of 4.7 years, HCM-related death occurred in 52 (11.3%) patients. Overall, there was a significant positive association between ALBI score and HCM-related death (adjusted hazard ratio [HR]: 1.79 per one standard deviation [SD] increment, 95% confidence interval [CI]: 1.36–2.35). When the score was assessed as tertiles, the adjusted HRs of HCM-related death were 1.30 (95% CI: 0.42–3.99) for the tertile 2 and 4.43 (95% CI: 1.65–11.89) for the tertile 3, compared with the tertile 1. Stratified analysis and E-value analysis suggested the robustness of the above-mentioned results. Meanwhile, time-dependent ROC analysis showed ALBI score could discriminate HCM-related death at various time points (AUC ranges: 0.725–0.850). Furthermore, exploratory analysis indicated the dynamic changes of ALBI score also could predict HCM-related death. Finally, multiple linear regression analysis suggested some pathogenetic pathways associated with HCM-related adverse outcomes significantly correlated with ALBI score, and the pathways included inflammation, myocardial injury, nutritional status and some clinical characteristics, but not abnormal cardiac structure and function itself.

Conclusions:

Higher ALBI score is a strong independent predictor of HCM-related death in patients with HCM.

Comparison of mortality and cause of death between adults with and without hypertrophic cardiomyopathy

Insufficient evidence is available comparing mortality and cause of death between general hypertrophic cardiomyopathy (HCM) and general non-HCM populations. We aimed to investigate how causes of death and mortality differ in subjects with and without HCM. Using the National Health Insurance Service database from 2009 to 2016, individuals who underwent health check-up(s) with or without a history of HCM were identified. Participants in the HCM group were matched at a 1:1 ratio with those in the non-HCM group using propensity scores calculated from the baseline covariates. Mortality rates and risks were compared between the groups. In total, 14,858 participants (7,429 each in the HCM and non-HCM groups) were followed up over a mean 4.4 ± 2.2 years (mean age, 61.0 years; male proportion, 66.8%). Compared to the non-HCM group, the HCM group showed a higher risk of all-cause and HCM-related mortality and a similar risk for non-cardiovascular mortality (hazard ratio [95% confidence interval] 1.57 [1.38–1.78], 2.71 [1.92–3.83], and 1.04 [0.88–1.23], respectively). The sensitivity analyses consistently showed that the HCM group showed higher risks of all-cause and HCM-related mortality than the non-HCM group. The female participants with HCM were associated with an increasing trend of the risks of all-cause mortality but not HCM-related mortality compared to their male counterparts (p for interaction < 0.001 and 0.185, respectively). In conclusion, compared to the non-HCM population, the general HCM population showed higher risks of both all-cause and HCM-related mortality, but had a similar risk of non-cardiovascular mortality.

Impact of diabetes mellitus on the outcomes of subjects with hypertrophic cardiomyopathy: A nationwide cohort study

AIMS

Diabetes mellitus (DM) often coexists in elderly hypertrophic cardiomyopathy (HCM) patients; however, its impact on clinical outcomes is unclear.

METHODS

We compared clinical outcomes according to the presence of DM in a nationwide HCM cohort.

RESULTS

In 9,883 HCM subjects (mean age 58.5 ± 13.1, men 71.7%), 1,327 (13.4%) had DM. During follow-up (mean 5.9 ± 2.5 years), end-stage renal disease (ESRD) progression, coronary events (myocardial infarction, coronary revascularization), heart failure (HF), cardiovascular mortality, and all-cause mortality occurred in 80 (0.8%), 365 (3.7%), 1,558 (15.8%), 354 (3.6%), and 877 (8.9%) subjects, respectively. DM HCM subjects had significantly higher risks of ESRD progression (HR 3.49, 95% CI 2.20-5.54) and HF (HR 1.15, 95% CI 1.01-1.32) compared to non-DM HCM subjects, independent of age, sex, ischemic heart disease, atrial fibrillation, and other comorbidities. There was a tendency for greater risk of ESRD progression, HF, and all-cause death in subjects with more advanced stage of DM (p-for-trend < 0.05 for all). Insulin-treated DM was associated with the highest risk.

CONCLUSIONS

DM HCM subjects have higher risk of ESRD progression and HF. Considering the extended life expectancy of HCM and increasing number of elderly HCM subjects, active surveillance and management of DM-related outcomes should be highlighted.

Emergency department utilization in patients with hypertrophic cardiomyopathy: a nationwide population-based study

Despite the increasing burden of hypertrophic cardiomyopathy (HCM) on healthcare resources, data on emergency department (ED) utilization in HCM are lacking. This nationwide population-based study extracted 14,542 HCM patients from the National Health Insurance Service database between 2015–2016, and investigated their ED utilization during a one-year period. The reason for ED utilization was defined as the primary diagnosis upon discharge from EDs. The clinical outcome was defined as hospitalization or all-cause mortality within 90 days after the ED visits. A total of 3209 (22.1%) HCM patients visited EDs within a one-year period (mean age, 66.8 ± 13.8 years; male, 57.4%). The majority (71.1%) of HCM patients who visited the EDs were aged ≥ 60 years. The ED utilization rate was higher in women than in men (26.3% versus 19.7%, P < 0.001). Cardiovascular diseases were the most common reason for ED visits (n = 1333, 41.5%). Among HCM patients who visited EDs, 1195 (37.2%) were hospitalized, and 231 (7.2%) died within 90 days. ED visits for cardiovascular disease was associated with a higher 90-day all-cause mortality (adjusted odds ratio, 2.72; 95% confidence interval 1.79–4.12). These findings would serve as a basis for future research to establish medical policies on ED utilization in HCM.

Major Clinical Issues in Hypertrophic Cardiomyopathy

By actively implementing contemporary management strategies in hypertrophic cardiomyopathy, morbidity and mortality can be substantially reduced. In this review, we discuss the pathophysiology and management of the major clinical issues in hypertrophic cardiomyopathy, including sudden cardiac death, atrial fibrillation and thromboembolism, dynamic left ventricular outflow tract obstruction, and heart failure progression. Although echocardiography and cardiac magnetic resonance imaging currently play an essential and complementary role in the management of hypertrophic cardiomyopathy, further studies are needed to establish how developing techniques such as myocardial deformation and late gadolinium enhancement can provide better risk stratification and guide treatment.

Hypertrophic cardiomyopathy (HCM) is one of the most common inheritable cardiomyopathies. Contemporary management strategies, including the advent of implantable cardioverter-defibrillators and effective anticoagulation, have substantially improved the clinical course of HCM patients; however, the disease burden of HCM is still high in Korea. Sudden cardiac death (SCD), atrial fibrillation and thromboembolic risk, dynamic left ventricular outflow tract (LVOT) obstruction, and heart failure (HF) progression remain important issues in HCM. SCD in HCM can be effectively prevented with implantable cardioverter-defibrillators. However, appropriate patient selection is important for primary prevention, and the 5-year SCD risk score and the presence of major SCD risk factors should be considered. Anticoagulation should be initiated in all HCM patients with atrial fibrillation regardless of the CHA₂DS₂-VASc score, and non-vitamin K antagonist oral anticoagulants are the first option. Symptomatic dynamic LVOT obstruction is first treated medically with negative inotropes, and if symptoms persist, septal reduction therapy is considered. The recently approved myosin inhibitor mavacamten is promising. HF in HCM is usually related to diastolic dysfunction, while about 5% of HCM patients show reduced left ventricular ejection fraction <50%, also referred to as “end-stage” HCM. Myocardial fibrosis plays an important role in the progression to advanced HF in patients with HCM. Patients who do not respond to guideline-directed medical therapy can be considered for heart transplantation. The development of imaging techniques, such as myocardial deformation on echocardiography and late gadolinium enhancement on cardiac magnetic resonance, can provide better risk evaluation and decision-making for management strategies in HCM.

Vasorin deficiency leads to cardiac hypertrophy by targeting MYL7 in young mice

Vasorin (VASN) is an important transmembrane protein associated with development and disease. However, it is not clear whether the death of mice with VASN deficiency (VASN^-/- ) is related to cardiac dysfunction. The aim of this research was to ascertain whether VASN induces pathological cardiac hypertrophy by targeting myosin light chain 7 (MYL7). VASN^-/- mice were produced by CRISPR/Cas9 technology and inbreeding. PCR amplification, electrophoresis, real-time PCR and Western blotting were used to confirm VASN deficiency. Cardiac hypertrophy was examined by blood tests, histological analysis and real-time PCR, and key downstream factors were identified by RNA sequencing and real-time PCR. Western blotting, immunohistochemistry and electron microscopy analysis were used to confirm the downregulation of MYL7 production and cardiac structural changes. Our results showed that sudden death of VASN^-/- mice occurred 21-28 days after birth. The obvious increases in cardiovascular risk, heart weight and myocardial volume and the upregulation of hypertrophy marker gene expression indicated that cardiac hypertrophy may be the cause of death in young VASN^-/- mice. Transcriptome analysis revealed that VASN deficiency led to MYL7 downregulation, which induced myocardial structure abnormalities and disorders. Our results revealed a pathological phenomenon in which VASN deficiency may lead to cardiac hypertrophy by downregulating MYL7 production. However, more research is necessary to elucidate the underlying mechanism.

Changes of serum uric acid and its clinical correlation in children with dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is the most common type of childhood cardiomyopathy and uric acid (UA) is considered closely associated with cardiovascular disease. There are few reports about the relationship between serum UA level and DCM in children, and the present study aimed to analyze the changes and clinical correlation of the two.

METHODS

The clinical data of 49 children under 16 years old and who were hospitalized with DCM, and 44 healthy children who underwent physical examination in the same period at Tianjin Children's Hospital from June 2015 to November 2019 were analyzed retrospectively.

RESULTS

The 49 children in the case group included 17 males and 32 females, aged from 2 to 172 months. The case group were divided into New York Heart Association (NYHA) functional class I (n=2), class II (n=17), class III (n=11), and class IV (n=19). The 44 healthy children selected as the control group included 20 males and 24 females aged from 2 to 161 months. The serum UA level was detected, and an ultrasonic cardiogram was conducted in each child. The serum UA level, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), and left atrial diameter (LAD) of the case group were higher than that of the control group, while the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were lower than that of the control group, and significant statistical differences were seen between the two groups (P<0.01). The serum UA level, LVEDD, LVESD, and LAD of NYHAIII-IV class patients were higher than that of the NYHAI-II class, but LVEF and LVFS were lower than that of the NYHA I-II class, and there were significant statistical differences between the two groups (P<0.01). Statistical correlations were seen between the serum UA level and NYHA functional class, LVEDD, LVESD, LAD, LVEF, and LVFS (rs=0.599, 0.567, 0.579, 0.475, -0.333, -0.341, respectively, P<0.05).

CONCLUSIONS

Elevated serum UA levels exist in children with DCM and correlate with NYHA functional class and ultrasonic values. Change in serum UA levels may be used as a biomarker reflecting the severity of DCM in children.