Outcomes of additional substrate modification in de novo atrial fibrillation ablation

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Data regarding additional substrate modification has been conflicting, both in paroxysmal and persistent atrial fibrillation.

Purpose

To assess the effect of additional linear substrate modification during de novo AF ablation on AF recurrence.

Methods

We reviewed 1575 AF ablations in 1254 patients from January 2013 to June 2021 at a single academic medical center. There were 1096 de novo ablations. We defined substrate modification as linear ablations including cavotricuspid isthmus (CTI), superior vena cava isolation, intercaval line, mitral isthmus, and left atrial roof and floor lines. We evaluated clinical and procedural characteristics to identify risk factors for AF recurrence and complications. Patients were followed for a minimum of 6 months.

Results

The 1096 de novo ablations included 65.5% males with mean age 61.1 years, mean BMI 31.3, 81.8% paroxysmal AF and 18.2% persistent AF. There were four AF ablation subgroups: PVI alone (41.6%), PVI and CTI ablation (37.1%), PVI with CTI and additional substrate modification (15.6%), and PVI with substrate modification without CTI ablation (5.7%). Overall, AF recurred in 36.9% cases. AF recurrence with PVI only ablation was 41% compared to 32.7% in patients with PVI and CTI ablation (p=0.02). When looking at patients with paroxysmal and persistent AF, results were similar, with decreased AF recurrence with the addition of CTI ablation in both paroxysmal (37.3% v. 29.2%, p=0.03) and persistent AF (58.1% v. 40.0%, p=0.02). Additional substrate modification did not result in significant difference in outcome in either paroxysmal or persistent AF (Figure 1).

Conclusions

In de novo AF ablations, addition of CTI ablation to de novo PVI ablation is associated with lower AF recurrence in both paroxysmal and persistent AF. Additional linear substrate modification did not impact outcomes.

Funding Acknowledgement

Type of funding sources: None.

Safety of same day discharge after atrial fibrillation ablation

Background

Atrial fibrillation (AF) ablation is an outpatient procedure with traditionally an overnight hospital observation (OHO). Recently, there has been a trend towards same day discharge (SDD).

Purpose

Compare AF ablation procedure safety outcomes with SDD vs. OHO.

Methods

We reviewed consecutive AF procedures performed from January 2013 to June 2021 at a single academic center. Patients underwent OHO until June 2020, after which patients had SDD whenever feasible. Adverse events were assessed at three months, which included pericardial effusion, pericarditis, post-procedure hypotension, embolic events, and vascular complications. We also assessed emergency department (ED) visits and procedure-related hospital admissions.

Results

There were 1254 patients who underwent 1575 AF ablations. 1440 patients underwent OHO and 135 had SDD. Mean age was 62.2 years, BMI 33 kg/m2, 65% were male, and 27.6% had persistent AF, without significant differences in baseline characteristics between OHO and SDD. We found that SDD was not associated with increased complications (OHO 0.20% v. SDD 0.49%; p>0.05), ED visits, or hospital admissions (2% v. 5%; p>0.05) (Figure 1, 2). There were no gender or age-related disparities in all outcomes (p>0.05).

Conclusion

SDD protocol after AF ablation is feasible and not associated with higher incidence of complications, ED visits, and procedure-related hospitalizations.

Funding Acknowledgement

Type of funding sources: None.

Effect of defibrillator on long term all-cause mortality in patients with chronic kidney disease: an updated meta-analysis

Background

The beneficial role of implantable defibrillator (ICD) in patients with chronic kidney disease (CKD) is less understood as this population is often not well represented in clinical trials.

Purpose

Evaluate the effect of ICD use in patients with CKD on long term outcomes.

Methods

Literature search was conducted for studies reporting the effect of ICD on all-cause mortality in patients with CKD, which is defined as glomerular filtration rate (GFR) <60 mL/min. The search was not restricted to time or publication status. The search included the following databases: Ovid MEDLINE, EMBASE, Scopus, Web of Science, Google Scholar, and EBSCO CINAHL. The minimum duration of follow-up required for inclusion was one year.

Results

The literature search identified 834 studies, of which 14 studies with 70,661 patients were included. Mean follow up was 39 months (12–81 months). For all patients with CKD, ICD was associated with lower all-cause mortality (log HR −0.247, SE 0.101, p=0.015); Heterogeneity: df=13 (P<0.01), I2=97.057; Test for overall effect: Z=−2.431 (Figure 1). When further stratified based on dialysis, CKD patients without the need for dialysis had favorable outcome (log HR −0.211, SE 0.095, p=0.026); Heterogeneity: df=6 (P<0.01), I2=70.146; Test for overall effect: Z=−2.225, whereas ICD implantation in CKD patients requiring dialysis was not associated with mortality benefit (log HR −0.262, SE 0.134, p=0.051) (Figure 2A, B).

Conclusion

ICD implantation is associated with mortality benefit in patients with CKD, but this association is not present for patients requiring dialysis.

Funding Acknowledgement

Type of funding sources: None.

Association of late-gadolinium enhancement in cardiac magnetic resonance with ventricular arrhythmias and mortality in patients with non-ischemic cardiomyopathy

Background

Late-gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) is a predictor of adverse events such as cardiovascular mortality, cardiovascular related hospitalization and defibrillation shocks in patients with non-ischemic cardiomyopathy (NICM). The correlation between LGE and ventricular arrhythmia and mortality has not been completely established.

Purpose

This meta-analysis assessed the relationship between LGE in CMR with ventricular arrhythmias: sustained, non-sustained and ICD therapy; and mortality in patients with NICM.

Methods

Databases were queried for studies reporting the association between LGE in CMR in NICM and ventricular arrhythmias and mortality, including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year.

Results

A total of 46 studies and 10,548 patients (4,610 with LGE vs 5,938 without LGE) were included; mean follow up was 3 years (ranging between 13 to 71 months) and mean left ventricular ejection fraction 33%. LGE in NICM was associated with increased risk of ventricular arrhythmias and sudden cardiac death (odds ratio 4.595, 95% confidence interval 3.54–5.97; P<0.01) and mortality (odds ratio 2.949, 95% confidence interval 2.285–3.806; P<0.01). Heterogeneity is low to moderate: χ2=82.2, df =45 (P=0.001), I2=45% (Figures 1, 2).

Conclusions

Our results suggest that LGE is associated with increased risk of ventricular arrhythmias, sudden cardiac death and mortality in long-term follow up. These results further substantiate the need for larger prospective randomized trials using LGE to decide ICD indication regardless of EF. There are two ongoing trials testing this indication: CMR-ICD and CMR-GUIDE.

Funding Acknowledgement

Type of funding sources: None.

Does body mass index affect atrial fibrillation ablation outcomes

Background

There are conflicting reports in the literature regarding whether body-mass index (BMI) influences the success and procedural complication rates of atrial fibrillation (AF) ablation.

Purpose

To determine if differences in BMI affect AF ablation outcomes

Methods

At a single academic center, AF ablation procedures were reviewed from 2013 to 2021. Primary outcomes were AF recurrence (after a 90 day blanking period), procedure-related complications, emergency department visits or hospital admission (ED/HOSP). Patients had a minimum of 6 months follow-up

Results

We analyzed 1569 AF ablation consecutive procedures (1093 de novo, 476 repeat ablation) using either radiofrequency or cryoablation. The study population was 65% male with a mean age 62 years, with 28% persistent AF. BMI was separated into three cohorts: <25 kg/m2 (N=218), 25–30 kg/m2 (N=547), and >30 kg/m2 (N=804). There were no significant differences in the type of AF, left atrial diameter, or left ventricular ejection fraction in the BMI subgroups. There was a direct relationship between the prevalence of co-morbid conditions and increasing BMI: hypertension (49.1%, 59.9%, 60.2%; p 0.04), diabetes (6.4%, 13.5%, 21.3%; p 0.01), and obstructive sleep apnea (5.5%, 10.8%, 26.7%; p<0.01). There were no significant differences in AF recurrence, procedural complications or ED/HOSP among the BMI cohorts (p>0.05) (Figure 1). No gender related disparities were noted in outcomes (p>0.05).

Conclusion

Higher BMI was not associated with AF recurrence, complications, or ED/HOSP after AF ablation despite a higher prevalence of comorbid medical conditions

Funding Acknowledgement

Type of funding sources: None.