Efficacy of Catheter Ablation for Atrial Fibrillation in Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Canadian Cardiovascular Society Clinical Practice Update on Contemporary Management of the Patient with Hypertrophic Cardiomyopathy

Numerous guidelines on the diagnosis and management of hypertrophic cardiomyopathy (HCM) have been published, by learned societies, over the last decade. While helpful they are often long and less adapted to non-experts. This writing panel was challenged to produce a document that grew as much from years of practical experience as it did from the peer-reviewed literature. As such, rather than produce yet another set of guidelines, we aim here to deliver a concentrate of our own experiential learning and distil for the reader the essence of effective and appropriate HCM care. This Clinical Practice Update on HCM is therefore aimed at general cardiologists and other cardiovascular practitioners rather than for HCM specialists. We set the stage with a description of the condition and its clinical presentation; discuss the central importance of 'obstruction' and how to look for it; review the role of cardiac magnetic resonance imaging; reflect on the appropriate use of genetic testing; review the treatment options for symptomatic HCM - crucially including cardiac myosin inhibitors; and deal concisely with practical issues surrounding risk assessment for sudden cardiac death, and management of the end-stage HCM patient. Uniquely, we have captured the pediatric experience on our panel to discuss appropriate differences in the management of younger patients with HCM. We ask the reader to remember that this document represents expert consensus opinion rather than dogma and to use their best judgement when dealing with the HCM patient in front of them.

From Atrial Fibrillation Management to Atrial Myopathy Assessment: The Evolving Concept of Left Atrium Disease in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetically inherited cardiovascular disorder in adults and a significant cause of heart failure and sudden cardiac death. Historically, atrial fibrillation (AF) has been considered as a critical aspect in HCM patients as it is considered to be a marker of disease progression, escalates the frequency of heart failure hospitalisations, increases the risk of thromboembolic events, and worsens quality of life and outcome. Increasing evidence suggests that AF is the result of a subtle long-standing process that starts early in the history of HCM. The process of left atrial dilation accompanied by morphologic and functional remodelling is the quintessential prerequisite for the onset of AF. This review aims to describe the current understanding of AF pathophysiology in HCM, emphasising the role of left atrial myopathy in its development. In addition, we discuss risk factors and management strategies specific to AF in the context of HCM, providing insights into the complexities and challenges of treating this specific patient population.

Hypertrophic Cardiomyopathy and Atrial Fibrillation: A Systematic Review and Meta-analysis of Anticoagulation Strategy

BACKGROUND

Atrial fibrillation (AF) frequently complicates hypertrophic cardiomyopathy (HCM), and anticoagulation significantly decreases the risk of stroke in this population. To date, no randomized controlled trials (RCTs) have compared direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs). The present study aimed to systematically compare the two anticoagulation strategies in terms of effectiveness and safety.

METHOD

We performed a systematic literature search and meta-analysis in the PubMed, MEDLINE, and EMBASE databases for studies reporting all-cause mortality, major bleeding, or thromboembolic events (TEs). Since no RCTs were available, we included observational studies only. The overall hazard ratio (HR) and 95% confidence interval (CI) for each analyzed parameter were pooled using a random-effects model.

RESULTS

Five observational studies including 6919 patients were eligible for inclusion. Compared with VKAs, DOACs were associated with statistically significant lower rates of all-cause mortality (HR 0.64, 95% CI 0.35-0.54; p < 0.00001), comparable major bleeding events (HR 0.64, 95% CI 0.40-1.03; p = 0.07), and TEs (HR 0.94, 95% CI 0.73-1.22; p = 0.65).

CONCLUSIONS

Compared with VKAs, a DOAC-based strategy might represent an effective and safe strategy regarding all-cause mortality, major/life-threatening bleeding complications, and TEs in HCM patients with concomitant AF. However, further prospective studies are necessary to reinforce a DOAC-based anticoagulation strategy in this population.