Comparison of Pulmonary Venous and Left Atrial Remodeling in Patients With Atrial Fibrillation With Hypertrophic Cardiomyopathy Versus With Hypertensive Heart Disease

Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation

Background

Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes and those without HCM at AF catheter ablation (AFCA) and analyzed post-AFCA reverse remodeling and AF recurrence based on HCM presence and subtype.

Methods

Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age-, gender-, and AF type-matched. Between AF-HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1-year follow-up, and procedural outcomes over the course of follow-up between two groups.

Results

A total of 122 AF-HCM patients and 318 control patients were included. AF-HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p < .001). However, LAWT did not differ from control group. A year after AFCA, degree of LA reverse remodeling was significantly lower in AF-HCM than in control group (ΔLA dimension, p = .025). Nonapical HCM (HR 1.71; 95% CI 1.05-2.80), persistent AF (HR 1.46; 95% CI 1.05-2.04), and LA dimension (HR 1.04; 95% CI 1.01-1.06) were independent risk factors for AF recurrence. During 78.0 months of follow-up, nonapical HCM patients showed higher AF recurrence rate than both apical HCM (log-rank p = .005) and control patients (log-rank p = .002).

Conclusions

The presence of HCM, particularly nonapical HCM, displayed increased LA hemodynamic loading with diastolic dysfunction and had poorer rhythm outcomes after AFCA compared to both apical HCM and control group.

Characteristics of left atrial remodeling in patients with atrial fibrillation and hypertrophic cardiomyopathy in comparison to patients without hypertrophy

Atrial fibrillation (AF) leads to remodeling characterized by changes in both size and shape of the left atrium (LA). Here we aimed to study the effect of hypertrophic cardiomyopathy (HCM) on the pattern of LA remodeling in AF-patients. HCM-patients (n = 23) undergoing AF ablation (2009–2012) were matched and compared with 125 Non-HCM patients from our prospective registry. Pre-procedural CT data were analyzed (EnSite Verismo, SJM, MN) to determine the maximal sagittal (anterior–posterior, AP), coronal (superior-inferior, SI and transversal, TV) dimensions and the sphericity index (LAS). Volume (LAV) was rendered after appendage (LAA) and pulmonary vein (PV) exclusion. A cutting plane, between PV ostia/LAA and parallel to the posterior wall, divided LAV into anterior- (LA­A) and posterior-LA (LA­P) parts. The ratio LA-A/LAV was defined as asymmetry index (ASI). HCM patients had a wider inter-ventricular septum and a smaller LV than Non-HCM patients. LA volume (LAV 166 ± 72 vs. 130 ± 36 ml, p = 0.03) and LA diameters were significantly larger in HCM patients. Anterior volume (LA-A: 112 ± 48 vs. 83 ± 26 ml, p < 0.001) differed significantly between groups, whereas the posterior volume LA-P (55 ± 28 vs. 47 ± 13 ml, p = 0.23) and LAS (75% vs. 78%, p = 0.089) was similar in both groups. As a result, ASI was significantly higher (67 ± 6 vs. 63 ± 6%, p = 0.01) in HCM than in Non-HCM patients. In conclusion, LA remodeling in patients with AF and HCM is characterized by asymmetric dilatation, driven by an anterior rather than a posterior dilatation. This can be characterized by three-dimensional imaging and could be used as surrogate of advanced atrial remodeling.

Interatrial distance predicts the necessity of additional carina ablation to isolate the right-sided pulmonary veins

Background

Ablation of the pulmonary vein (PV) carina is occasionally required for PV isolation (PVI). Marshall bundle and epicardial connections between the right-sided PV (RtPV) carina and right atrium (RA) may be one of the mechanisms that necessitates carina ablation.

Objective

We sought to clarify anatomical characteristics predictive of the necessity of carina ablation.

Methods

Forty-five consecutive patients undergoing radiofrequency catheter ablation of atrial fibrillation were prospectively included in this study. Left atrial (LA) and PV size and morphology, and interatrial distance in the posterior aspect, were measured on cardiac computed tomography (CT) images.

Results

For right-sided PVI, the patients were divided into 2 groups based on the necessity of RtPV carina ablation, Carina-ABL group (n = 21) and Non-Carina-ABL group (n = 24). The distance between the anterior portion of the RtPV carina and RA was shorter in the Carina-ABL group vs in the Non-Carina-ABL group (7.7 ± 1.7 mm/m² vs 9.5 ± 2.3 mm/m²; P = .005), whereas other anatomical parameters (LA and RA volumes, right inferior PV angle, and ostial diameters of the RtPVs) did not differ between the groups. For left-sided PVI, the ostial diameter and circumference of the left superior PV were smaller in the Carina-ABL group (n = 13) vs the Non-Carina-ABL group (n = 32) (8.6 ± 2.1 mm/m² vs 7.3 ± 1.5 mm/m²; P = .044, and 34.9 ± 6.0 mm/m² vs 30.1 ± 5.1 mm/m²; P = .017, respectively).

Conclusions

A shorter interatrial distance for right-sided PVI and a smaller PV ostium for left-sided PVI were associated with the necessity of additional carina ablation. The presence and location of the epicardial fibers may be affected by the atrial and PV geometry.

Utilization and Complications of Catheter Ablation for Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Background

Atrial fibrillation (AF) is common and bears a major clinical impact in patients with hypertrophic cardiomyopathy (HCM). We aimed to investigate the use and real‐world safety of catheter ablation for AF in patients with HCM.

Methods and Results

We drew data from the US National Inpatient Sample to identify cases of AF ablation in HCM patients between 2003 and 2015. Sociodemographic and clinical data were collected, and incidence of catheter ablation complications, mortality, and length of stay were analyzed, including trends between the early (2003–2008) and later (2009–2015) study years. Among a weighted total of 1563 catheter ablation cases in patients with HCM, the median age was 62 (interquartile range, 52–72), 832 (53.2%) were male, and 1150 (73.6%) were white. The average annual volume of AF ablations in patients with HCM doubled between the early and the later study period (79–156). At least 1 complication occurred in 16.1% of cases, and the in‐hospital mortality rate was 1%. Cardiac and pericardial complications declined from 8.8% to 2.3% and from 2.8% to 0.9%, respectively, between the early and the later study years (P<0.01). Independent predictors of complications included female sex (odds ratio [OR], 4.81; 95% CI, 2.72–8.51), diabetes mellitus (OR, 6.57; 95% CI, 2.68–16.09) and obesity (OR, 3.82; 95% CI, 1.61–9.06).

Conclusions

Despite some decline in procedural complications over the years, catheter ablation for AF is still associated with a relatively high periprocedural morbidity and even mortality in patients with HCM. This emphasizes the importance of careful clinical consideration, by an experienced electrophysiologist, in referring patients with HCM for an AF ablation.