Differences in postablation cardiac MRI scar between radiofrequency and cryoballoon ablation: A DECAAF II subanalysis

Introduction

Pulmonary vein isolation (PVI) using radiofrequency (RF) and cryoballoon (Cryo) ablation are standard approaches for rhythm control in patients with symptomatic atrial fibrillation. Both strategies create scars in the left atrium (LA). There have been few studies investigating the difference in scar formation between patients undergoing RF and Cryo using cardiac magnetic resonance (CMR) imaging.

Methods

The current study is a subanalysis of the control arm of the Delayed-Enhancement MRI Determinant of Successful Catheter Ablation of Atrial Fibrillation study (DECAAF II). The study was a multicenter, randomized, controlled, single-blinded trial that evaluated atrial arrhythmia recurrence (AAR) between PVI alone and PVI plus CMR atrial fibrosis-guided ablation. Preablation CMR and 3- to 6-month postablation CMR were obtained to assess baseline LA fibrosis and scar formation, respectively.

Results

Of the 843 patients randomized in the DECAAF II trial, we analyzed the 408 patients in the primary analysis control arm that received standard PVI. Five patients received combined RF and Cryo ablations, so they were excluded from this subanalysis. Of the 403 patients analyzed, 345 underwent RF and 58 Cryo. The average procedure duration was 146 min for RF and 103 min for Cryo (p = .001). The rate of AAR at ~15 months occurred in 151 (43.8%) patients in the RF group and 28 (48.3%) patients in the Cryo group (p = .62). On 3-month post-CMR, the RF arm had significantly more scar (8.8% vs. 6.4%, p = .001) compared to Cryo. Patients with ≥6.5% LA scar (p < .001) and ≥2.3% LA scar around the PV antra (p = .01) on 3-month post-CMR had less AAR independent of the ablation technique. Cryo caused a greater percentage of right and left pulmonary vein (PV) antral scar (p = .04, p = .02) and less non-PV antral scar (p = .009) compared to RF. On Cox regression, Cryo patients free of AAR had a greater percentage of left PV antral scar (p = .01) and less non-PV antral scar (p = .004) compared to RF free of AAR.

Conclusion

In this subanalysis of the control arm of the DECAAF II trial, we observed that Cryo formed a more significant percentage of PV antral scar and less non-PV antral scar compared to RF. Post ablation LA scar ≥6.5% predicted freedom from AAR, independent of ablation technique. These findings may have prognostic implications in ablation technique selection and freedom from AAR.     

QTc interval measurement in patients with right bundle branch block: A practical method

Background and Aim

Prolonging the QT interval in the right bundle branch block (RBBB) can create challenges for electrophysiologists in estimating repolarization time and eliminating the effect of depolarization changes on QT interval. In this study, we aimed to develop a practice formula to eliminate the effect of depolarization changes on QT interval in patients with RBBB.

Methods

This prospective study evaluated accidentally induced RBBB in patients undergoing electrophysiological study. Two expert electrophysiologists recorded the ECG parameters, including QRS duration, QT interval, and cycle length, in the patients. The formula was developed based on QT interval differences (with and without RBBB) and its proportion to QRS. Additionally, the Bazzet, Rautaharju, and Hodge formulas were used to evaluate QTc.

Results

We evaluated 96 patients in this study. The mean QT interval without RBBB was 369.39 ± 37.38, reaching 404.22 ± 39.23 after inducing RBBB. ΔQT was calculated as 34.83 ± 17.61, and the ratio of ΔQT/QRS with RBBB was almost 23%. Our formula is: (QT_{with RBBB} − 23% × QRS). Subtraction of 25% instead of 23% seems more straightforward and practical. Our formula could also predict the QTc interval in RBBB based on the Bazzet, Rautaharju, and Hodge formulas.

Conclusion

Previous formulas for QT correction were hard to apply in the clinical setting or were not specified for RBBB. Our new formula allows a rapid and practical method for QT correction in RBBB in clinical practice.     

Hepatitis delta virus infection prevalence,diagnosis and treatment in the Middle East: A scoping review

Hepatitis D virus (HDV) infection is a global public health concern, especially because of its unique existence in the presence of hepatitis B virus infection. HDV infection is estimated to affect 12 million people globally. Having a clearer understanding of its prevalence in all regions of the world is essential for helping direct preventive and early interventional treatment. This mini-review assessed the literature over the last 10 years to determine the prevalence, diagnostic means and treatment guidelines available for HDV in the Middle East. The search found limited data available in 21 articles, of which 18 were studies focused on Iran. Prevalence rates ranged dramatically among the countries, and none of the 12 countries included in the search had specific HDV guidelines. This review highlights the urgent need for more precise data for the Middle East region to help establish early diagnosis and treatment options for HDV.     

Weight loss breaks the bond between nonalcoholic fatty liver disease and cardiovascular diseases: A clinical and epidemiological perspective

Nonalcoholic fatty liver disease (NAFLD) is a growing health concern that is closely related to obesity and metabolic syndrome. In particular, NAFLD has been increasingly reported in adolescents and young adults in recent years. Cardiovascular diseases (CVDs) such as cardiac remodeling, heart failure, myocardial infarction, valvular heart diseases, and arrhythmia are more common in patients with NAFLD. CVD are the major cause of mortality in NAFLD. Although NAFLD often affects patients with obesity/overweight, it can also affect subjects with normal body mass index (BMI), known as lean NAFLD, which has a strong correlation with CVD. Obesity imposes a considerably increased risk of NAFLD and CVD. Consistently, weight-lowering approaches that can pronouncedly decrease body weight and maintain it in the long term, such as bariatric surgery and treatment with semaglutide and tirzepatide, have been promising in alleviating both CVD and NAFLD. Interestingly, compared with patients with NAFLD and obesity, a minimal amount of weight loss resolves NAFLD in lean patients. Besides the widespread use of bariatric surgery, the development of new GLP-1 agonists and GLP-1 GIP agonists revolutionized the treatment of obesity in recent years. Here, we discuss the interwoven correlation between obesity, NAFLD, and CVD and the benefits of weight-lowering approaches.     

Unpacking COVID-19 and conspiracy theories in the UK black community

Objectives

Conspiracy theories are associated with significant COVID-19 health consequences including lower engagement with protective behaviours. This study uses sensemaking theory, a process of constructing meanings through interpersonal exchanges that enable people to interpret their world to explain the theoretical process underlying the development of conspiratorial beliefs around COVID-19 within Black African and Caribbean communities in the UK.

Design

Qualitative, in-depth interviews were used.

Methods

Twenty-eight members of the communities were recruited: semi-structured interviews were analysed using grounded theory.

Results

Our findings provide an explanation of how an environment of crisis combined with current and historical mistrust, perceived injustice and inequality provided a context in which alternative conspiracy narratives could thrive. The nature of these conspiratorial beliefs made more sense to many of our respondent's than institutional sources (such as the UK Government). Critically, these alternative beliefs helped respondents shape their decision-making, leading to non-engagement with COVID protective behaviours.

Conclusions

We conclude that the uncertainty of the pandemic, combined with historical and contemporary perceived injustice and mistrust, and a lack of specific identity-aligned messaging, created a perfect environment for conspiratorial sense-making to thrive. This alternative sensemaking was inconsistent with the health-protection messaging espoused by the Government. To ensure all groups in society are protected, and for health promotion messages to take purchase, the experiences of different target audiences must be taken into account, with sensemaking anchored in lived experience.