A total of 1509 patients who had legacy pacemakers or defibrillators underwent 2103 MRIs according to a prespecified safety protocol. No long-term clinically significant adverse events were reported.
Abstract Objectives The aims of this study were to: 1) use a novel method of late gadolinium enhancement (LGE) quantification that uses normalized intensity measures to confirm the association ...between LGE extent and atrial fibrillation (AF) recurrence following ablation; and 2) examine the presence of interaction and effect modification between LGE and AF persistence. Background Recurrent AF after catheter ablation has been reported to associate with the baseline extent of left atrial LGE on cardiac magnetic resonance. Traditional methods for measurement of intensity lack an objective threshold for quantification and interpatient comparisons of LGE. Methods The cohort included 165 participants (mean age 60.0 ± 10.2 years, 77% men, 57% with persistent AF) who underwent initial AF ablation. The association of baseline LGE extent with AF recurrence was examined using multivariable Cox proportional hazards models. Multiplicative and additive interactions between AF type and LGE extent were examined. Results During 10.2 ± 5.7 months of follow-up, 63 patients (38.2%) experienced AF recurrence. Baseline LGE extent was independently associated with AF recurrence after adjusting for confounders (hazard ratio: 1.5 per 10% increased LGE; p < 0.001). The hazard ratio for AF recurrence progressively increased as a function of LGE. The magnitude of association between LGE >35% and AF recurrence was greater among patients with persistent AF (hazard ratio: 6.5 p = 0.001 vs. 3.6 p = 0.001); however, there was no evidence for statistical interaction. Conclusions Regardless of AF persistence at baseline, participants with LGE ≤35% have favorable outcomes, whereas those with LGE >35% have a higher rate of AF recurrence in the first year after ablation. These findings suggest a role for: 1) patient selection for AF ablation using LGE extent; and 2) substrate modification in addition to pulmonary vein isolation in patients with LGE extent exceeding 35% of left atrial myocardium.
Atrial flutter (AFL) is a common form of arrhythmia recurrence after atrial fibrillation (AF) ablation. We aimed to define (1) the incidence of AFL and (2) the clinical factors associated with ...cavo-tricuspid isthmus dependent (typical) and atypical AFL, after AF ablation. The retrospective cohort consisted of 1,029 patients that underwent initial radiofrequency AF ablation from May 2005 to December 2013 at a single academic center. Patients with missing follow-up data, history of AFL ablation, and those with undocumented AFL were excluded. Atrial volumes were measured using three-dimensional cardiac computed tomography or magnetic resonance imaging. A total of 607 patients were included in the final cohort (age 59.2 ± 10.6 years, 76.0% men, 58.7% paroxysmal AF). During a median follow-up of 845 days (interquartile range 389 to 1,597 days), 122 (20.1%) patients developed AFL. Of these, 17 had typical AFL, 98 had atypical AFL, and 7 patients had both circuits. In the multivariable Cox regression analysis, only right atrial volume index (hazard ratio HR 1.25 per 10 ml/m2, confidence interval CI 95% 1.10 to 1.42) was associated with incident typical AFL; whereas persistent AF (HR 1.59, CI 95% 1.06 to 2.40), linear lesions (HR 1.58, CI 95% 1.02 to 2.46) and left atrial volume index (HR 1.17 per 10 ml/m2, CI 95% 1.07 to 1.27) were associated with incident atypical AFL. In conclusion, noninvasive measures of right and left atrial remodeling are strongly associated with incident AFL after AF ablation. Strategies to prevent incident AFL using these measures after index ablation warrant further investigation.
The purpose of this study was to evaluate the usefulness of intra-atrial dyssynchrony as a marker of underlying left atrial (LA) remodeling to predict recurrence after the first atrial fibrillation ...(AF) ablation.
Catheter ablation for AF remains far from curative with relatively high recurrence rates. One of the causes of recurrence is poor patient selection out of a diverse patient population with different degrees of LA remodeling.
We included 208 patients with a history of AF (59.4 ± 10.0 years of age; 26.0% nonparoxysmal AF) referred for catheter ablation of AF who underwent pre-ablation cardiac magnetic resonance in sinus rhythm. Clinical follow-up was 20 ± 6 months. Using tissue tracking cardiac magnetic resonance, we measured the LA longitudinal strain in each of 12 equal-length segments in 2- and 4-chamber views. We defined intra-atrial dyssynchrony as the standard deviation of the time to the peak longitudinal strain corrected by the cycle length (SD-time to peak strain TPS, %).
Patients with AF recurrence after ablation (n = 101) had significantly higher SD-TPS than those without (n = 107; 3.9% vs. 2.2%; p < 0.001). Multivariable cox analysis showed that SD-TPS was associated with recurrence after adjusting for clinical risk factors, AF type, LA structure and function, and fibrosis (p < 0.001). Furthermore, receiver-operating characteristics analysis showed SD-TPS improved prediction of recurrence better than clinical risk factors, LA structure and function, and fibrosis.
Intra-atrial dyssynchrony during sinus rhythm is an independent predictor of recurrence after the first catheter ablation of paroxysmal or persistent AF. Assessment of intra-atrial dyssynchrony may improve ablation outcomes by refining patient selection.
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Although reverse remodeling of the left atrium (LA) has been shown after MitraClip placement in degenerative mitral regurgitation (MR), changes in LA strain and strain rate have not been evaluated in ...these patients or compared with surgical mitral valve repair.
We included 87 subjects (mean age 59.7±12.3 years) with degenerative MR enrolled in the randomized EVEREST II trial (Endovascular Valve Edge-to-Edge Repair Study II). Baseline peak positive LA strain (ε) and strain rates along with longitudinal left ventricular strain (LV ε) were compared with 12-month follow-up measures. At 12 months, all 38 mitral valve repair subjects had ≤2+ MR, and 31 of the 49 MitraClip had ≤2+ MR. Baseline LA strain and strain rate values were similar in MitraClip and mitral valve repair groups. Of the strain rate measures, only peak early diastolic strain rate was consistently decreased in all treatment arms. In patients with reduced baseline LA ε, no significant change in LA ε occurred in either the MitraClip or mitral valve repair group despite significant MR and LA volume reduction. However, in patients with normal or high baseline ε, successful MR reduction by either method resulted in return of LA ε to normative values. There was a significant correlation between LA ε, LV ε values, and change in LA ε and LV ε over time.
Changes seen in LA ε seem to depend on baseline LA and LV function. Changes in LA ε after MR reduction may reflect a decrease in LA expansion but may also be influenced by the degree of pre-existing LA dysfunction.
URL: https://www.clinicaltrials.gov. Unique identifier: NCT00209274.
Prognostic significance of left atrial (LA) function in patients with atrial fibrillation (AF) is poorly defined.
To examine the association of LA function measured with cardiac magnetic resonance ...(CMR) feature-tracking and AF recurrence following catheter ablation.
One hundred and twenty-one AF patients (72% paroxysmal, mean age 59 ± 10 years) were enrolled. Baseline LA function was measured by calculating passive, active, and total emptying fractions (LAEF) and analysis of global longitudinal strain and strain rates. Patients were followed up for recurrence of AF or atrial tachycardia (AT). Hazard ratios for recurrence were calculated using Cox proportional models adjusted for potential clinical confounders, type of AF, left ventricular ejection fraction, AF duration, LA volume, and late gadolinium enhancement (LGE).
During a mean follow-up of 18 ± 9 months, 52 patients (43%) experienced recurrent AF/AT. Patients with recurrent AF/AT had higher baseline LA volume index and lower LA passive, and total LAEF (P < .05 for all). The baseline peak LA strain and strain rates in all phases of LA function were lower in the AF/AT recurrence group (P < .01 for all). In multivariable analysis total LAEF, peak LA strain, and systolic and late diastolic strain rates were associated with recurrence. Both peak LA strain and total LAEF improved prediction of recurrent AT/AF compared to the baseline clinical model, including LA LGE (C statistic 0.82 vs 0.77, P < .05 for both total LAEF and peak LA strain).
LA reservoir function was independently associated with recurrent AF/AT after PVI and can additionally improve risk stratification in patients undergoing PVI.
Background
Typical atrial flutter (AFL) often occurs in patients with atrial fibrillation (AF). Decision-making tools for application of prophylactic cavo-tricuspid isthmus (CTI) ablation at the time ...of AF ablation may improve outcomes. In this study, we sought to define the right atrial (RA) functional characteristics of AF patients with documented typical AFL.
Methods
Consecutive patients that underwent cardiac magnetic resonance (CMR) prior to initial AF ablation in the Johns Hopkins Hospital were enrolled. The AF database was reviewed to identify prevalent and incident documented typical AFL. Feature tracking CMR analysis during sinus rhythm was utilized to quantify RA longitudinal strain and strain rate, as well as RA passive and active emptying fractions derived from phasic RA volumes.
Results
A total of 115 patients were analyzed (mean age 59.1 ± 11.4 years, 78.3% male, 74.8% paroxysmal AF). Of all patients, 30 (26.1%) had typical AFL. Clinical characteristics and AF type did not differ among groups defined by the absence or presence of typical AFL. In contrast, RA longitudinal strain (41.6 ± 16.8% vs. 55.8 ± 17.1%,
p
≤ 0.001), systolic strain rate (1.71 ± 0.85 s
−1
vs. 2.33 ± 0.93 s
−1
,
p
= 0.002), and late diastolic strain rate (1.78 ± 1.02 s
−1
vs. 2.50 ± 0.91 s
−1
p
≤ 0.001) were significantly lower in patients with typical AFL. Although RA passive emptying fraction was similar among groups (18.9 ± 8.1 vs. 19.5 ± 8.0,
p
= 0.75), RA active emptying fraction was lower in patients with typical AFL (34.8 ± 12.3 vs. 40.8 ± 12.1,
p
= 0.02).
Conclusions
The reservoir and pump function of the RA is significantly reduced in patients with typical AFL. Prophylactic CTI ablation warrants further study as adjunctive therapy to AF catheter ablation in selected patients with RA dysfunction.
Abstract Catheter ablation has been widely used to manage recurrent atrial and ventricular arrhythmias. It has been established that contrast-enhanced magnetic resonance can accurately characterize ...the myocardium. In this review, we summarize the role of cardiac magnetic resonance in identification of arrhythmogenic substrates, and the potential utility of cardiac magnetic resonance for catheter ablation of complex atrial and ventricular arrhythmias.
The extent of left atrial (LA) late gadolinium enhancement (LGE), as a surrogate for fibrosis, has been associated with atrial fibrillation (AF) recurrence after catheter ablation. Furthermore, there ...is ex vivo evidence that islands of fibrosis may anchor fibrillatory rotors.
The purpose of this study was to examine the anatomical association of AF rotors with LA and right atrial (RA) LGE on cardiac magnetic resonance.
The cohort included 9 patients with persistent AF (mean age 61.1 ± 9.7 years) who underwent LGE cardiac magnetic resonance before AF ablation using the focal impulse and rotor modulation system. The extent of LA and RA LGE was quantified globally and in each of the 7 sectors: LA posterior/inferior wall, anterior wall, roof, left and right pulmonary vein antra, and RA lateral and septal regions. The multivariable association of rotor incidence with global and per sector LGE extent was examined using multivariable Bernoulli logistic regression estimated by generalized estimating equations.
The mean RA and LA volumes were 113.2 ± 37.31 and 143.03 ± 58.25 mL, respectively. The mean RA and LA LGE burden was 17.2% ± 11.0% and 17.4% ± 14.4%, respectively. A total of 18 LA rotors and 9 RA rotors were identified in all patients. No univariable or multivariable association was observed between global or per sector LGE extent and focal impulse and rotor modulation rotor incidence.
In this cohort of patients, there was no association between AF rotor incidence and the global or regional extent of RA and LA LGE.
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