Antiarrhythmic drug therapy and all-cause mortality after catheter ablation of atrial fibrillation: A propensity-matched analysis

Role of dofetilide in patients with ventricular arrhythmias

BACKGROUND OR PURPOSE

To assess effectiveness of dofetilide in reducing the burden of ventricular arrhythmias (VAs).

BACKGROUND

Prior small sample studies show that dofetilide has benefit in reducing VA. However, large sample investigations with long-term follow-up are lacking.

METHODS

Two hundred seventeen consecutive patients admitted between January 2015 and December 2021 for dofetilide initiation for control of VA were assessed. Dofetilide was successfully started in 176 patients (81%) and had to be discontinued in the remaining 41 patients (19%). Dofetilide was initiated for control of ventricular tachycardia (VT) in 136 patients (77%), whereas 40 (23%) patients were initiated on dofetilide for reducing the burden of premature ventricular complexes (PVCs).

RESULTS

The mean follow-up was 24 ± 7 months. In total, among the 136 VT patients, 33 (24%) died, 11 (8%) received a left ventricular assist device (LVAD), and 3 (2%) received a heart transplant during follow-up. Dofetilide was discontinued in 117 (86%) patients due to lack of sustained effectiveness during follow-up. Dofetilide use was associated with similar odds of the composite outcome of all-cause mortality/LVAD/heart transplant (OR: 0.97, 0.55-4.23) in patients with ischemic cardiomyopathy (ICM) compared to those with non-ischemic cardiomyopathy (NICM). Dofetilide did not reduce PVC burden during follow-up in the 40 patients with PVCs (mean baseline PVC burden: 15%, at 1-year follow-up: 14%).

CONCLUSIONS

Dofetilide use was less effective in reducing VA burden in our cohort of patients. Randomized controlled studies are needed to confirm our findings.

Obstructive sleep apnea and its management in patients with atrial fibrillation: An International Collaboration of Sleep Apnea Cardiovascular Trialists (INCOSACT) global survey of practicing cardiologists

Background

Among international cardiologists it is unclear whether equipoise exists regarding the benefit of diagnosing and managing obstructive sleep apnea (OSA) to improve atrial fibrillation (AF) outcomes and whether clinical practice and equipoise are linked.

Methods

Between January 2019 and June 2020 we distributed a web-based 12-question survey regarding OSA and AF management to practicing cardiologists in 16 countries.

Results

The United States, Japan, Sweden, and Turkey accounted for two-thirds of responses. 863 cardiologists responded; half were general cardiologists, a quarter electrophysiologists. Responses regarding treating OSA with CPAP to improve AF endpoints were mixed. 33% of respondents referred AF patients for OSA screening. OSA was diagnosed in 48% of referred patients and continuous positive airway pressure (CPAP) was prescribed for 59% of them. Nearly 70% of respondents believed randomized controlled trials (RCTs) of OSA treatment in AF patients were necessary and indicated willingness to contribute to such trials.

Conclusions

There was no clinical equipoise among surveyed cardiologists; a majority expressed certainty that combined OSA and AF treatment is superior to AF treatment alone for improving AF outcomes. However, a minority of surveyed cardiologists referred AF patients for OSA testing, and while half of screened AF patients had OSA, CPAP was prescribed in little more than half of them, reflecting the view that better clinical trial evidence is needed to support this practice. Our results underscore the need for larger, multi-national prospective studies of OSA treatment and AF outcomes to inform more uniform society guideline recommendations.

Two-year outcomes of pulmonary vein isolation and cava-tricuspid isthmus radiofrequency ablation vs pharmacological only antiarrhythmic therapy: a single center experience

The benefit of radiofrequency ablation (RFA) in rhythm control in atrial fibrillation (AF) and flutter patients is uncertain, but risk of death, arrhythmia recurrence and other post ablation complications remains high. Existing data on the impact of pulmonary vein isolation and cava-tricuspid isthmus RFA on long-term prognosis of patients with AF and flutter and its advantage over pharmacological antiarrhythmic therapy (AAT) are insufficient and contradictory. The aim: we sought to evaluate two-year outcomes of pulmonary vein isolation and cava-tricuspid isthmus RFA vs pharmacological only AAT according to a single center experience. Material and methods: we enrolled 174 patients after pulmonary vein isolation RFA, cava-tricuspid isthmus RFA and their combination and 122 patient who did not undergo RFA and got pharmacological AAT only. Results: there was no significant difference in mortality between the RFA and AAT only groups (5.8 % and 9.0 % respectively) with the same structure of causes of death. The Caplan-Meyer curve analysis demonstrated better survivance (p=0.031) after RFA just during first year of observation. RFA effectiveness in arrhythmia relapse prevention was the highest for cava-tricuspid isthmus RFA procedure and worst – in group of combined pulmonary vein isolation and cava-tricuspid isthmus procedures. RFA showed an advantage over AAT in smaller quantities of non-fatal cardiovascular events (p<0.001) and cardiovascular hospitalizations (p=0.0026). Conclusions: RFA of pulmonary vein isolation and cava-tricuspid isthmus RFA decrease arrhythmia episodes frequency, risk of non-fatal cardiovascular events and cardiovascular hospitalizations. Timely combined PVI and CTI procedure is associated with worsening of all outcomes.

Angiotensin II-Treated Cardiac Myocytes Regulate M1 Macrophage Polarization via Transferring Exosomal PVT1

Atrial fibrillation (AF) seriously reduces the health and life quality of patients. It is necessary to explore the pathogenesis of AF and provide a new target for the treatment. Here, exosomes were identified using transmission electron microscopy and nanoparticle tracing analysis. Western blotting assay was performed to detect the expression of exosomal surface markers, extracellular matrix-related proteins, and IL-16. The expression of genes was measured using qRT-PCR. Flow cytometry was performed to examine the percentages of CD86- and CD163-positive macrophages. Besides, luciferase activity assay was performed to explore the combination between PVT1 and miR-145-5p and the combination between miR-145-5p and IL-16 3'UTR. The combination between PVT1 and miR-145-5p also was examined using RIP assay. In our study, we isolated human cardiac myocyte- (HCM-) derived exosomes successfully. Ang-II-treated HCM-derived exosomes (Ang-II-Exo) promoted M1 macrophage polarization. PVT1 was highly expressed in Ang-II-Exo. Ang-II-Exo induced macrophage to M1 polarization through transferring PVT1. Furthermore, our data showed that PVT1 increased the expression of IL-16 via sponging miR-145-5p. Finally, we proved that exosomal PVT1 could boost the extracellular matrix remodeling of atrial fibroblasts. Overall, our data demonstrated that Ang-II-Exo promoted the extracellular matrix remodeling of atrial fibroblasts via inducing M1 macrophage polarization by transferring PVT1. PVT1 facilitated M1 polarization macrophage via increasing IL-16 expression by sponging miR-145-5p. Our results provided a new evidence for PVT1 which might be a treatment target of AF.

Comparative Efficacy of Dofetilide Versus Amiodarone in Patients With Atrial Fibrillation

OBJECTIVES

The study's goal was to compare the efficacy and safety of dofetilide (DOF) versus amiodarone (AMIO) in patients with atrial fibrillation (AF).

BACKGROUND

Comparative efficacy of DOF versus AMIO in patients with AF has not been well established. In addition, proarrhythmia has been a concern with DOF therapy.

METHODS

Rhythm control was attempted by using DOF in 657 consecutive patients (mean age 72 ± 9 years; 35% women) with AF (n = 528) or atrial flutter and AF (n = 129) between January 2014 and December 2018.

RESULTS

DOF was successfully initiated in 573 (87%) of 657 patients, including 510 (89%) with persistent AF and 63 (11%) with paroxysmal AF. During a mean follow-up of 19 ± 7 months, sinus rhythm was maintained in 361 (63%) of the 573 DOF-treated patients. At 12 months, patients on DOF had a similar likelihood of experiencing recurrent atrial arrhythmias compared with the 2,476 consecutive patients treated with AMIO for rhythm control during the study period (37% vs. 39%; p = 0.56). The efficacy of DOF and AMIO was also similar in specific subgroups of patients, including patients >75 years of age, with a low left ventricular ejection fraction, obesity, renal insufficiency, and prior catheter ablation for AF. Among patients with atypical atrial flutter, likelihood of recurrent atrial flutter was similar between the DOF (43 of 108 [40%]) and AMIO (211 of 555 [38%]; p = 0.69) groups.

CONCLUSIONS

When properly initiated and monitored, DOF has efficacy comparable to that of amiodarone for rhythm control in patients with AF.

Knots to untie: anticoagulant and antiarrhythmic therapy after ablation for atrial fibrillation

The continuation or otherwise of anticoagulant and antiarrhythmic therapy after ablation of atrial fibrillation (AF) is one of the main aspects still to be defined in the electrophysiological field. The currently available data do not allow the assumption of certain positions due to the lack of randomized studies on the subject. With regard to anticoagulant therapy, however, the suggestion of the guidelines to assess more the risk profile than the result of the ablation and consequently to prescribe anticoagulant treatment to all patients with CHADSVASc ≥2 seems acceptable. Its use in the first two or three months after the procedure appears reasonable; however, keeping in mind that the objective of this strategy is limited to the prevention of early recurrences only. More prolonged use of antiarrhythmics seems to be more promising, but further data are necessary before it can be recommended routinely. The ablation of AF is a therapy that is widely spreading and its use is continuously growing. Since it is a recently introduced method, not everything is still clear about it. The continuation or not of anticoagulant and antiarrhythmic therapy after ablation for AF is one of the main aspects yet to be defined.