Development of atrial fibrillation in patients with rheumatic mitral valve disease in sinus rhythm

Characteristics and Problems of Rheumatic Heart Disease in Indonesia: The Ina-RHD Multicenter Study

BACKGROUND

Rheumatic heart disease (RHD) presents a significant public health challenge. Unfortunately, there is a lack of national data regarding the incidence and prevalence of RHD in Indonesia.

OBJECTIVES

The purpose of this study was to evaluate the characteristics, burdens, and problems of RHD in Indonesia.

METHODS

We collected medical reports of RHD patients over 18 years of age from 21 hospitals. Secondary data about clinical and echocardiography was collected to describe the characteristics, disease conditions, and complications of the disease.

RESULTS

We recruited 3,431 patients, average age was 44 years, and 64.4% (2,209 of 3,431) were women. Dyspnea was found in 85.7% (2,939 of 3,431), and 25% (862 of 3,431) of patients with NYHA functional class III to IV. Isolated mitral stenosis was the most prevalent valve lesion in 1,357 of 3,431 patients (39.6%). A total of 62.5 % (2,146 of 3,431) of patients had atrial fibrillation (AF), with the highest prevalence being in MV lesions. Vitamin K antagonist was prescribed in 2,411 of 3,431 (70.3%) of patients. A history of stroke was reported in 227 of 3,431 (6.6%) of patients and most frequently happened in isolated mitral stenosis patients 128 of 1,357 (9.4%). Finally, secondary prophylaxis was only administered in 1,279 of 3,431 (37.3%) of patients, and only 23.2% (796 of 3,431) had it regularly.

CONCLUSIONS

Our patients were predominantly women and had isolated mitral stenosis. Many patients came at a later stage of the disease, with older average age, a high prevalence of AF, pulmonary hypertension, and right heart involvement. The challenges were suboptimal use of anticoagulation despite the high prevalence of AF and underused secondary prophylaxis.

Ultrasound assessment of the association between left atrial remodeling and fibrosis in patients with valvular atrial fibrillation: a clinical investigation

BACKGROUND

Advanced heart failure in patients with valvular atrial fibrillation (VAF) poses a significant threat to human health. Noninvasive assessment of left atrial remodeling in various pathological conditions is instrumental in guiding clinical treatment decisions, evaluating efficacy, and predicting prognosis.

METHODS

The study enrolled 63 patients diagnosed with mitral stenosis (MS), among whom 44 presented concomitant atrial fibrillation (AF) and 19 had sinus rhythm. Left atrial volume and functional parameters were evaluated using real-time three-dimensional echocardiography (RT-3DE) and two-dimensional speckle tracking imaging (2D-STI) techniques, while left atrial stiffness index (LASI) was calculated accordingly. During surgery, left atrial myocardial specimens were obtained to determine the CVF through histopathological evaluation, reflecting the extent of left atrial myocardial fibrosis. Comparative analysis was conducted between the AF group and the control group regarding left atrial volume, functional parameters, LASI, as well as their correlation with CVF.

RESULTS

(1) Patients with MS combined with AF exhibit larger left atrial volume, decreased strain at all stages, reduced function, and increased stiffness of the left atrium compared to patients in sinus rhythm. (2) LASI was positively correlated with CVF in both the control and AF groups, exhibiting the highest correlation coefficient (p < 0.05).

CONCLUSION

The application of RT-3DE, 2D-STI, and LASI enables effective evaluation of left atrial structure and function changes in patients with VAF. LASI provides a more accurate indication of the extent of myocardial fibrosis.

CLINICAL TRIAL NUMBER

Not applicable.

Magnitude and associated factors of atrial fibrillation, and its complications among adult rheumatic heart diseases patients in governmental hospitals in Bahir Dar Town, Northwest Ethiopia 2024

INTRODUCTION

Atrial fibrillation (AF) is characterized by high frequency stimulation of the atrium, causes dyssynchronous atrial contraction and irregular ventricular excitation. It is the most known cardiac arrhythmia in adults, doubles the risk of stroke five times and is associated with an increasing public health burden. This study was aimed to assess the magnitude and associated factors of atrial fibrillation and its complication among adult rheumatic heart diseases patients in governmental hospitals in Bahir Dar town, Northwest Ethiopia 2024.

METHODS

An institutional based cross-sectional study design was conducted with a sample size of 421. A simple random sampling technique was used to select participants. The data were entered into the Statistical Package for the Social Sciences (SPSS) version 26 for analysis. Adjusted Odds Ratio (AOR) with a 95% confidence interval was used to determine associated factors of atrial fibrillation. A binary logistic regression model was used, and a P-value < 0.05 in multivariate was considered as a statistically significant.

RESULTS

The response rate was 95% and atrial fibrillation was developed in 51.2% of patient. Majority of them were Female (56%). The median age of patients was 41, with an interquartile range (IQR) of 26-51. Age > 50 years old (AOR = 7.20(2.03-25.46)), sever tricuspid regurgitation 4.50(1.18-17.20)), and left ventricular ejection fraction (LVEF) % (AOR = 0.94(0.89-0.99)), left atrium size (AOR = 1.23(1.14-1.33)) were independently associated with atrial fibrillation. For every unit increment of left ventricular ejection fraction in percent, the odds of developing atrial fibrillation decreased by 6%. For every unit increment of left atrial size in millimeter2 (mm2), the odds of developing atrial fibrillation increased by 23%. The present study showed that complication related to AF was heart failure (HF) (72.8%), ischemic stroke (34.4%), systemic thromboembolism (12.1).

CONCLUSION

More than half of the study participants were found to have atrial fibrillation in patients with rheumatic heart disease. Being age > 50 years old, left atrium size, severity of tricuspid regurgitation (severe), and LVEF% were associated in developing atrial fibrillation. The atrial fibrillation was linked to an increased risk of ischemic stroke, heart failure, systemic thromboembolism, and death.

Management of atrial fibrillation in rheumatic heart disease

Rheumatic heart disease (RHD) is the underlying cause of a significant proportion of atrial fibrillation (AF) in the low- and middle-income countries, while nonvalvular AF is the most common cause of AF in high-income countries. RHD is also common among African Americans, migrants, and the indigenous population of high-income countries. The onset of AF in RHD patients is a clinical marker of worse outcomes and is associated with significant morbidity and mortality. Despite RHD being a major cause of morbidity and mortality in the young in many parts of the world, it is often neglected by policymakers, the media, and even the medical fraternity. Stroke risk assessment using various risk scores has not been systematically evaluated in rheumatic AF patients. Rate control may not be ideal for symptom control in rheumatic AF patients considering the young age and an active lifestyle. There is limited information regarding the nonpharmacological management of rheumatic AF. The current management guidelines based on nonvalvular AF do not apply to rheumatic AF patients who are often younger, are women, and have fewer comorbidities. This review critically looks at specific areas such as stroke prevention with reference to direct oral anticoagulants, cardioversion, rate and rhythm control strategies, and the role of nonpharmacological methods in rheumatic AF management. Future recommendations must be cognizant of local health care systems and resourcing considering the geographic distribution of the disease.

Incidence of Acute Cerebrovascular Events in Patients with Rheumatic or Calcific Mitral Stenosis: A Systematic Review and Meta-analysis

BACKGROUND

Patients with mitral stenosis (MS) may be predisposed to acute cerebrovascular events (ACE) and peripheral thromboembolic events (TEE). Concomitant atrial fibrillation (AF), mitral annular calcification (MAC) and rheumatic heart disease (RHD) are independent risk factors. Our aim was to evaluate the incidence of ACEs in MS patients and the implications of AF, MAC, and RHD on thromboembolic risks.

METHODS

This systematic review was registered on PROSPERO (CRD42021291316). Six databases were searched from inception to 19th December 2021. The clinical outcomes were composite ACE, ischaemic stroke/transient ischaemic attack (TIA), and peripheral TEE.

RESULTS

We included 16 and 9 papers, respectively, in our qualitative and quantitative analyses. The MS cohort with AF had the highest incidence of composite ACE (31.55%; 95%CI 3.60-85.03; I²=99%), followed by the MAC (14.85%; 95%CI 7.21-28.11; I²=98%), overall MS (8.30%; 95%CI 3.45-18.63; I²=96%) and rheumatic MS population (4.92%; 95%CI 3.53-6.83; I²=38%). Stroke/TIA were reported in 29.62% of the concomitant AF subgroup (95%CI 2.91-85.51; I²=99%) and in 7.11% of the overall MS patients (95%CI 1.91-23.16; I²=97%). However, the heterogeneity of the pooled incidence of clinical outcomes in all groups, except the rheumatic MS group, were substantial and significant. The logit-transformed proportion of composite ACE increased by 0.0141 (95% CI 0.0111-0.0171; p<0.01) per year of follow-up.

CONCLUSION

In the MS population, MAC and concomitant AF are risk factors for the development of ACE. The scarcity of data in our systematic review reflects the need for further studies to explore thromboembolic risks in all MS subtypes.

Is left atrial fibrosis an independent determinant of atrial fibrillation in mitral stenosis?

We prospectively studied whether left atrial (LA) fibrosis is a determinant of atrial fibrillation (AF) in mitral stenosis in patients who underwent balloon mitral valvotomy. There were 2 groups: Group A (n = 16), with AF and Group B (n = 27), without AF. Fibrosis was assessed by MRI. Patients underwent cardioversion before MRI. There were 27 females and 16 males, aged 29 ± 6 years. The LA areas in Groups A and B were 54.3 ± 4.4 mm² and 39.4 ± 2.3 mm² (p < 0.05) and the LA volume index was 46.2 ± 2.9 ml/m² vs 33 ± 3 ml/m² respectively (p < 0.0001). The presence of LA scarring was not statistically different in the two groups.

Diagnosing rheumatic heart disease: where are we now and what are the challenges?

INTRODUCTION

Rheumatic heart disease (RHD), a sequela of acute rheumatic fever (ARF), affects 40.5 million people worldwide. The burden of disease disproportionately falls on low- and middle-income countries (LMIC) and sub-populations within high-income countries (HIC). Advances have been made in earlier detection of RHD, though several barriers to ideal management persist.

AREAS COVERED

This article reviews the current burden of RHD, highlighting the disparate impact of disease. It also reviews the clinical and echocardiographic presentation of RHD, as some may present in late stages of disease with associated complications. Finally, we review the advances which have been made in echocardiographic screening to detect latent RHD, highlighting the challenges which remain regarding secondary prophylaxis management and uncertainty of best practices for treatment of latent RHD.

EXPERT OPINION

Advances in technology and validation of portable echocardiography have made screening and identifying latent RHD feasible in the most burdened regions. However, uncertainty remains around best management of those with latent RHD and best methods to ensure ideal secondary prophylaxis for RHD. Research regarding latent RHD management, as well as continued work on innovative solutions (such as group A streptococcal vaccine), are promising as efforts to improve outcomes of this preventable disease persist.

Sinus rhythm voltage fingerprinting in patients with mitral valve disease using a high-density epicardial mapping approach

Aims

Unipolar voltage (UV) mapping is increasingly used for guiding ablative therapy of atrial fibrillation (AF) as unipolar electrograms (U-EGMs) are independent of electrode orientation and atrial wavefront direction. This study was aimed at constructing individual, high-resolution sinus rhythm (SR) UV fingerprints to identify low-voltage areas and study the effect of AF episodes in patients with mitral valve disease (MVD).

Methods and results

Intra-operative epicardial mapping (interelectrode distance 2 mm) of the right and left atrium, Bachmann’s bundle (BB), and pulmonary vein area was performed in 67 patients (27 male, 67 ± 11 years) with or without a history of paroxysmal AF (PAF). In all patients, there were considerable regional variations in voltages. UVs at BB were lower in patients with PAF compared with those without [no AF: 4.94 (3.56–5.98) mV, PAF: 3.30 (2.25–4.57) mV, P = 0.006]. A larger number of low-voltage potentials were recorded at BB in the PAF group [no AF: 2.13 (0.52–7.68) %, PAF: 12.86 (3.18–23.59) %, P = 0.001]. In addition, areas with low-voltage potentials were present in all patients, yet we did not find any predilection sites for low-voltage potentials to occur.

Conclusion

Even in SR, advanced atrial remodelling in MVD patients shows marked inter-individual and regional variation. Low UVs are even present during SR in patients without a history of AF indicating that low UVs should carefully be used as target sites for ablative therapy.

Caveolin-1 Deficiency Induces Atrial Fibrosis and Increases Susceptibility to Atrial Fibrillation by the STAT3 Signaling Pathway

ABSTRACT

Atrial fibrillation (AF) is a common arrhythmia in the clinic. Ablation failure and recurrence after cardioversion have become medical problems worldwide. An important pathological feature of AF is atrial fibrosis, which increases susceptibility to AF. As an important target of fibrosis signal integration, the signal transducer and activator of transcription 3 (STAT3) signaling pathway plays an important role in fibrosis. Caveolin-1 (CAV1), a cell membrane protein, is involved in a variety of the biological functions of cells. However, the role of CAV1 in atrial fibrosis remains unclear. In this study, Masson's trichrome staining was used to detect the degree of atrial fibrosis, and the expression of CAV1 in the human atrium was evaluated by immunohistochemistry. To further study the role of CAV1, its expression in cultured rat atrial fibroblasts was silenced using siRNAs. Atrial fibroblasts were treated with angiotensin II to observe the effects on CAV1 and the transforming growth factor-β1 and STAT3 signaling pathways. We also detected the effects of CAV1 scaffolding domain (CSD) peptide on fibrosis through the addition of exogenous CSD peptide. The results showed that CAV1 expression decreased with the aggravation of atrial fibrosis and that this effect increased the incidence of AF. The depletion of CAV1 induced excessive extracellular matrix deposition by activating the STAT3 and transforming growth factor-β1/SMAD2 signaling pathways, and this effect was exacerbated by stimulation with angiotensin II and improved by CSD peptide. These data suggested that CAV1 not only plays a critical role in fibrosis progression but also provides a target for the treatment of atrial fibrosis and AF.

Incidence and predictors of stroke in patients with rheumatic heart disease

OBJECTIVE

Ischaemic stroke is a severe complication of rheumatic heart disease (RHD), which may result in permanent disability and death. This study aimed to assess the incidence and predictors of stroke in patients with RHD in the current era of evidence-based recommendations for prevention.

METHODS

Consecutive patients with RHD diagnosed by clinical and echocardiographic criteria were selected. A structured clinical and neurological assessment was performed to determine the aetiology and classification of stroke at enrolment. The primary endpoint was an ischaemic cerebrovascular event, which included fatal or non-fatal stroke. Risk of stroke was estimated accounting for competing risks.

RESULTS

A total of 515 patients were enrolled, 438 women (85%), 46±12 years of age. The most frequent valve lesion was mixed mitral (80%). At the time of enrolment, 92 patients (18%) had a prior stroke, with anterior circulation infarction being the most frequent topography (72%). During the mean follow-up of 3.9 years, 27 patients (5.2%) had stroke with the overall incidence of 1.47 strokes per 100 patient-years. Predictors of stroke by the Cox model were prior stroke (adjusted HR 5.395, 95% CI 2.272 to 12.811), age (HR 1.591, 95% CI 1.116 to 2.269) and atrial fibrillation (AF) at baseline (HR 2.945, 95% CI 1.083 to 8.007). By considering death as a competing risk, the effect of AF on stroke risk was attenuated (HR 2.287, 95% CI 0.962 to 5.441).

CONCLUSIONS

In this large cohort of patients with RHD, stroke occurred in 5.2% of the patients, which was predicted by age, AF and prior stroke. The effect of AF on stroke risk estimation was influenced by death as competing risk.

Meta-Analysis of the Incidence, Prevalence, and Correlates of Atrial Fibrillation in Rheumatic Heart Disease

Objective:

To estimate the incidence, prevalence, and correlates of atrial fibrillation (AF) in a global population with rheumatic heart disease (RHD).

Methods:

Bibliographic databases were searched to identify all published studies providing data on AF in patients with RHD. Random-effects meta-analysis method was used to pool estimates.

Results:

Eighty-three studies were included, reporting data from 75,637 participants with RHD in 42 countries. The global prevalence of AF in RHD was 32.8% (range: 4.3%–79.9%). It was higher in severe valvular disease (30.8% vs 20.7%, p = 0.009), in severe mitral valve disease compared to severe aortic disease (30.4% vs 6.3%, p = 0.038). The global cumulative incidence of AF in patients with RHD was 4.8%, 11.4%, 13.2%, and 30.8% at 1, 2, 5, and 10 years of follow-up, respectively. From comparison between patients with and without AF, AF was associated with increased age (mean difference [MD]: 9.5 years; 95% CI: 7.8–1.3), advanced heart failure (odds ratio [OR]: 4.4; 95% CI 2.1–9.3), tricuspid valve involvement (OR: 4.0; 95% CI: 3.0–5.3), history of thromboembolism (OR: 6.2; 95% CI: 3.4–11.4), highly sensitive C-reactive protein (MD: 5.5 mg/dL; 95% CI: 1.2–9.8), systolic pulmonary arterial pressure (MD: 3.6 mmHg; 95% CI: 0.8–6.3), right atrium pressure (MD: 1.5 mmHg; 95% CI: 1.0–2.0), and left atrium diameter (MD: 8.1 mm; 95% CI: 5.5–10.7).

Conclusions:

About one-third of patients with RHD have AF, with an incidence which almost triples every five years after diagnosis. Factors associated with AF include age, advanced heart failure, thromboembolism, and few cardiac hemodynamics parameters.

Prevalence, risk determinants and consequences of atrial fibrillation in rheumatic heart disease: 6 years hospital based-Himachal Pradesh- Rheumatic Fever/Rheumatic Heart Disease (HP-RF/RHD) Registry

OBJECTIVE

To report the prevalence, risk factors and consequences of atrial fibrillation (AF) in patients of rheumatic heart disease (RHD).

METHODS

The Himachal Pradesh- Rheumatic Fever/Rheumatic Heart Disease (HP-RF/RHD) Registry database of 1918 patients was analyzed. AF was diagnosed with 12-lead ECG recording at entry in to the registry. The association of AF with nature and severity of valvular dysfunction was analyzed, adjusted for age, left atrial (LA) dimension and pulmonary arterial hypertension using multivariable logistic regression model and strength of association was reported as odds ratio (OR) with 95% confidence intervals (C. I.).

RESULTS

The study population consisted of young (40.2 ± 14.3 years), predominantly females (72.3%) from rural area (94.1%). Prevalence of AF was 23.9% (95% C. I. 22.1%-25.8%). The independent determinants AF were age (OR 1.04, 95% C.I. 1.03-1.06), LA size (OR 1.10, 95% C.I. 1.08-1.11). The association of AF with age, New York Heart Association functional class, mitral stenosis severity and tricuspid regurgitation was statistically significant and graded. Mitral regurgitation and aortic valve disease had no significant independent association with AF. The prevalence of heart failure, stroke, peripheral embolism and mortality was significantly higher among patients with AF (p < .01).

CONCLUSION

AF is common in RHD patients and is significantly associated with heart failure and systemic thromboembolism. Age, mitral stenosis severity, tricuspid regurgitation and LA size were independently associated with AF.

Risk factors for new-onset atrial fibrillation: A focus on Asian populations

The incidence of new-onset atrial fibrillation (NOAF) is increasing both in the Asian populations and Western countries. Several demographic and clinical risk factors were independently associated with NOAF, including ageing, male sex, obesity, obstructive sleep apnea syndrome, hypertension, coronary artery disease, renal dysfunction and heart failure. However, some differences in the incidence of NOAF, the prevalence of some risk factors and lifestyle or environmental conditions may exist between Asian and Western countries. Early recognition and holistic management of risk factors in an integrated manner may help reduce the burden of NOAF and its complications. While some risk scores have been developed to predict the risk of NOAF, thus far none are currently recommended or adequately validated to be used as a screening tool especially in the Asian population. The present semi-systematic review article aims to provide a comprehensive overview on the risk factors associated to NOAF, focusing on those explored in the Asian populations.

Potential role of MG53 in the regulation of transforming-growth-factor-β1-induced atrial fibrosis and vulnerability to atrial fibrillation

Atrial fibrosis plays a critical role in atrial fibrillation (AF) by the transforming growth factor (TGF)-β1/Smad pathway. The disordered differentiation, proliferation, migration and collagen deposition of atrial fibroblasts play significant roles in atrial fibrosis. Mitsugumin (MG)53 is predominantly expressed in myocardium of rodents and has multiple biological functions. However, the role of MG53 in cardiac fibrosis remains unclear. This study provided clinical and experimental evidence for the involvement of MG53 in atrial fibrosis in humans and atrial fibrosis phenotype in cultured rat atrial fibroblasts. In atrial tissue from patients we demonstrated that MG53 was expressed in human atrium. Expression of MG53 increased with the extent of atrial fibrosis, which could induce AF. In cultured atrial fibroblasts, depletion of MG53 by siRNA caused down-regulation of the TGF-β1/Smad pathway, while overexpression of MG53 by adenovirus up-regulated the pathway. MG53 regulated the proliferation and migration of atrial fibroblasts. Besides, exogenous TGF-β1 suppressed expression of MG53. In conclusion, we demonstrated that MG53 was expressed in human atrium, and may be a potential upstream of the TGF-β1/Smad pathway in human atrium and rat atrial fibroblasts. This suggests that MG53 is a potential regulator of atrial fibrosis induced by the TGF-β1/Smad pathway in patients with AF.

Increased α-Actinin-2 Expression in the Atrial Myocardium of Patients with Atrial Fibrillation Related to Rheumatic Heart Disease

OBJECTIVES

Atrial fibrosis, a marker of atrial structural remodeling, plays a critical role in atrial fibrillation (AF). α- Actinin-2 is associated with structural remodeling related to stretching. The transforming growth factor-β1 (TGF-β1)/Smad pathway plays an important role in atrial fibrosis. We investigated the effects of the TGF-β1/Smad signaling pathway on α-actinin-2 in atrial fibrosis in patients with AF.

METHODS

Forty-one right atrial specimens obtained from patients with rheumatic heart disease (RHD) were divided into a chronic (c)AF group, i.e. RHD + cAF (n = 29), and a sinus rhythm group, i.e. RHD + sinus rhythm (n = 12). Patients with congenital heart disease (CHD) and sinus rhythm who underwent heart surgery served as controls (n = 10). Fibrosis was assessed by histological examination, and expression of α-actinin-2, TGF-β1 and Smad2/phosphorylated Smad2 (p-Smad2) was evaluated by immunohistochemistry, quantitative real-time PCR and Western blotting. In rat atrial fibroblasts treated with TGF-β1, the collagen content was measured using hydroxyproline detection, and α-actinin-2 and p-Smad2 were evaluated by semiquantitative reverse-transcription PCR and Western blotting.

RESULTS

The histology results revealed a significant increase in atrial fibrosis in AF patients. The collagen content, mRNA and protein expression levels of α-actinin-2 and the components of the TGF-β1/Smad signaling pathway were significantly gradually increased in the CHD + sinus rhythm, RHD + sinus rhythm and RHD + cAF groups (p < 0.05). The mRNA and protein levels of α-actinin-2 and TGF-β1 in RHD patients were positively correlated with the collagen volume fraction. A positive correlation between the expression of α-actinin-2 and TGF-β1 was also observed. In rat atrial fibroblasts treated with TGF-β1, the collagen content was greater than that in the control group (p < 0.05), and the expression levels of α- actinin-2 and p-Smad2 were also upregulated (p < 0.05).

CONCLUSIONS

α-Actinin-2 expression was increased in the atrial tissues of patients with AF secondary to RHD. α-Actinin-2 was upregulated via the TGF-β1/Smad pathway in atrial fibroblasts, which suggests that it may be involved in TGF-β1/Smad pathway-induced atrial fibrosis in patients with AF.