Integrated Care in Atrial Fibrillation: A Road Map to the Future

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice with an epidemiological coupling appreciated with advancing age, cardiometabolic risk factors, and structural heart disease. This has resulted in a significant public health burden over the years, evident through increasing rates of hospitalization and AF-related clinical encounters. The resultant gap in health care outcomes is largely twinned with suboptimal rates of anticoagulation prescription and adherence, deficits in symptom identification and management, and insufficient comorbid cardiovascular risk factor investigation and modification. In view of these shortfalls in care, the establishment of integrated chronic care models serves as a road map to best clinical practice. The expansion of integrated chronic care programs, which include multidisciplinary team care, nurse-led AF clinics, and use of telemedicine, are expected to improve AF-related outcomes in the coming years. This review will delve into current gaps in AF care and the role of integrated chronic care models in bridging fragmentations in its management.

Clinical and cardiac structural predictors of atrial fibrillation persistence

AIMS

The persistence of atrial fibrillation (AF) has been associated with differential clinical outcomes, with studies showing that persistent and permanent AF results in increased morbidity and mortality when compared to the paroxysmal subtype. Given the established prognostic implications of AF subtype, we sought to discern the clinical and structural cardiac parameters associated with persistent/ permanent AF.

MATERIALS AND METHODS

Consecutive patients admitted to our institution between January 2013 and January 2018 with a primary diagnosis of non-valvular AF who underwent comprehensive transthoracic echocardiography were retrospectively appraised. Assessment of clinical and echocardiographic parameters was undertaken and compared according to AF subtype.

RESULTS

Of 1010 patients, 665 (mean age 66.8 ± 13.5 years, 53% men) had comprehensive transthoracic echocardiography on index admission and were included in the primary analysis. The majority of patients (n = 468; 70%) had paroxysmal AF while 197 (30%) had persistent/ permanent AF. Multivariable logistic regression analysis showed that heart failure (adjusted OR 3.135; 95% CI 2.099 to 4.682, P < .001), right atrial (RA) area ≥18 cm² (adjusted OR 2.147; 95% CI 1.413 to 3.261, P < .001) and left atrial emptying fraction (LAEF) ≤34% (adjusted OR 2.959; 95% CI 1.991 to 4.398, P < .001) were independent predictors of persistent /permanent AF.

CONCLUSIONS

The presence of heart failure, increased RA size and impaired LA function were associated with persistent/ permanent AF. These clinical and cardiac structural risk markers of AF persistence may identify a target population for early intervention to prevent adverse cardiovascular outcomes.

Uraemic Cardiomyopathy: A Review of Current Literature

Uraemic Cardiomyopathy (UC) is recognised as an intricate and multifactorial disease which portends a significant burden in patients with End-Stage Renal Disease (ESRD). The cardiovascular morbidity and mortality associated with UC is significant and can be associated with the development of arrythmias, cardiac failure and sudden cardiac death (SCD). The pathophysiology of UC involves a complex interplay of traditional implicative factors such as haemodynamic overload and circulating uraemic toxins as well as our evolving understanding of the Chronic Kidney Disease-Mineral Bone Disease pathway. There is an instrumental role for multi-modality imaging in the diagnostic process; including transthoracic echocardiography and cardiac magnetic resonance imaging in identifying the hallmarks of left ventricular hypertrophy and myocardial fibrosis that characterise UC. The appropriate utilisation of the aforementioned diagnostics in the ESRD population may help guide therapeutic approaches, such as pharmacotherapy including beta-blockers and aldosterone-antagonists as well as haemodialysis and renal transplantation. Despite this, there remains limitations in effective therapeutic interventions for UC and ongoing research on a cellular level is vital in establishing further therapies.

Coronary artery vasculitis: a review of current literature

Cardiac vasculitis is recognized as a heterogeneous disease process with a wide spectrum of manifestations including pericarditis, myocarditis, valvular heart disease and less frequently, coronary artery vasculitis (CAV). CAV encompasses an emerging field of diseases which differ from conventional atherosclerotic disease and have a proclivity for the younger population groups. CAV portends multiple complications including the development of coronary artery aneurysms, coronary stenotic lesions, and thrombosis, all which may result in acute coronary syndromes. There are several aetiologies for CAV; with Kawasaki's disease, Takayasu's arteritis, Polyarteritis Nodosa, and Giant-Cell Arteritis more frequently described clinically, and in literature. There is a growing role for multi-modality imaging in assisting the diagnostic process; including transthoracic echocardiography, cardiac magnetic resonance imaging, computed tomography coronary angiography, fluorodeoxyglucose-positron emission tomography and conventional coronary angiogram with intravascular ultrasound. Whilst the treatment paradigms fundamentally vary between different aetiologies, there are overlaps with pharmacological regimes in immunosuppressive agents and anti-platelet therapies. Interventional and surgical management are is a consideration in select populations groups, within a multi-disciplinary context. Further large-scale studies are required to better appropriately outline management protocols in this niche population.

The Role of Multi-modality Imaging in the Diagnosis of Cardiac Amyloidosis: A Focused Update

Cardiac amyloidosis (CA) is a unique disease entity involving an infiltrative process, typically resulting in a restrictive cardiomyopathy with diastolic heart failure that ultimately progresses to systolic heart failure. The two most common subtypes are light-chain and transthyretin amyloidosis. Early diagnosis of this disease entity, especially light-chain CA subtype, is crucial, as it portends a poorer prognosis. This review focuses on the clinical utility of the various imaging modalities in the diagnosis and differentiation of CA subtypes. This review also aims to highlight the key advances in each of the imaging modalities in the diagnosis and prognostication of CA.

Ventricular Arrhythmias in Cardiac Amyloidosis: A Review of Current Literature

Cardiac Amyloidosis is an infiltrative cardiomyopathy which occurs secondary to deposition of mis-folded protein in the myocardium, with the two most common subtypes being AL amyloidosis and TTR amyloidosis. The pathogenesis of the disease is multifaceted and involves a variety of mechanisms including an inflammatory response cascade, oxidative stress and subsequent separation of myocyte fibrils. Cardiac Amyloidosis frequently results in congestive cardiac failure and arrhythmias, from a disruption in cardiac substrate with subsequent electro-mechanical remodelling. Disease progression is usually demonstrated by development of progressive pump failure, which may be seen with a high arrhythmic burden, usually portending a poor prognosis. There is a paucity of literature on the clinical implications of ventricular arrhythmias in the context of cardiac amyloidosis. The important diagnostic investigations for these patients include transthoracic echocardiography, cardiac magnetic resonance imaging and an electrophysiology study. Whilst there are no robust management guidelines, studies have indicated benefits from contemporary pharmacological therapy and case-by-case catheter ablation. There are novel directed therapies available for TTR amyloidosis that have shown to improve overall survival. The role of ICD therapy in cardiac amyloidosis is controversial, with benefits seen predominantly in early phases of the disease process. The only definitive surgical therapy includes heart transplantation, but is largely indicated for progressive decompensated heart failure (Figure 1). Further large-scale studies are required to better outline management paradigms for treating ventricular arrhythmias in cardiac amyloidosis.

Drivers of hospitalization in atrial fibrillation: A contemporary review

Atrial fibrillation (AF)-related hospitalization has risen over the last 2 decades and is the most influential determinant of total disease-related expenditure. In this review article, we describe several identified drivers of hospitalization from several registries and large-scale clinical trials, including key cardiovascular and non-traditional risk factors. We also discuss available assessment tools for discerning overall risk of hospitalization, including AF symptom scores, thrombosis and bleeding disposition, and non-invasive cardiac structural assessment. Finally, we highlight the different treatment paradigms that have been proven to reduce AF burden, progression, and hospitalization in the literature.

Impairment of left atrial function and cryptogenic stroke: Potential insights in the pathophysiology of stroke in the young

•

Young patients with cryptogenic strokes have preserved left atrial size.

•

Left atrial dysfunction is present in young patients with cryptogenic stroke.

•

Left atrial strain is a discriminator of atrial dysfunction in cryptogenic stroke.

•

Young paroxysmal AF have abnormal left atrial size and function.

Background

Stroke is one of the leading causes of morbidity and mortality with a significant percentage classified as cryptogenic. Left atrial (LA) remodelling, a substrate for atrial fibrillation (AF) and stroke development, may play a role in identification of the aetiology of cryptogenic stroke. We aimed to examine LA function to gain mechanistic insights into the pathophysiology of cryptogenic stroke in young patients otherwise at low risk for cardiovascular disease.

Methods

Patients aged <60 years without traditional cardiovascular risk factors and who were diagnosed with ischaemic cryptogenic stroke or TIA were evaluated and compared to healthy controls and patients with paroxysmal AF with a CHA₂DS₂-VA score of 0. Conventional and novel left ventricular (LV) and LA echocardiographic parameters between the three groups were assessed.

Results

Each group consisted of thirty patients. There were no significant differences in LV parameters (LVEF, LV endoGLS) between groups. LA strain in stroke patients was significantly lower compared to the controls (median 33%; interquartile range (IQ) [32/39] vs 31 [27/34]; p = 0.008). LA strain was significantly lower in AF patients compared to stroke patients (median 21% [19/22] vs 31% [27/34]; p < 0.0001).

Conclusion

A stepwise reduction in measures of LA function was appreciated between controls, young stroke and paroxysmal AF groups. This may indicate dynamic LA remodelling occurring in the young stroke population and suggest a shared causal mechanism for stroke development in this group. LA strain may further refine the risk for cardioembolic stroke.