Atrial Fibrosis Helps Select the Appropriate Patient and Strategy in Catheter Ablation of Atrial Fibrillation: A DE-MRI Guided Approach (original) (raw)
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F1000 - Post-publication peer review of the biomedical literature, 2011
Introduction-Left atrial (LA) fibrosis and ablation related scarring are major predictors of success in rhythm control of atrial fibrillation (AF). We used delayed enhancement MRI (DE-MRI) to stratify AF patients based on pre-ablation fibrosis and also to evaluate ablation-induced scarring in order to identify predictors of a successful ablation. Methods and Results-One hundred and forty-four patients were staged by percent of fibrosis quantified with DE-MRI, relative to the LA wall volume: minimal or Utah stage 1; <5%, mild or Utah stage 2; 5-20%, moderate or Utah stage 3; 20-35%, and extensive or Utah stage 4; >35%. All patients underwent pulmonary vein (PV) isolation and posterior wall and septal debulking. Overall, LA scarring was quantified and PV antra were evaluated for circumferential scarring 3 months post ablation. LA scarring post ablation was comparable across the 4 stages. Most patients had either no (36.8%) or 1 PV (32.6%) antrum circumferentially scarred. Forty-two patients (29%) had recurrent AF over 283 ± 167 days. No recurrences were noted in Utah stage 1. Recurrence was 28% in Utah stage 2, 35% in Utah stage 3, and 56% in Utah stage 4. Recurrence was predicted by circumferential PV scarring in Utah stage 2 and by overall LA wall scarring in Utah stage 3. No recurrence predictors were identified in Utah stage 4. Conclusions-Circumferential PV antral scarring predicts ablation success in mild LA fibrosis, while posterior wall and septal scarring is needed for moderate fibrosis. This may help select the proper candidate and strategy in catheter ablation of AF.
MRI Assessment of Ablation-Induced Scarring in Atrial Fibrillation: Analysis from the DECAAF Study
Journal of Cardiovascular Electrophysiology, 2015
Background: There is limited knowledge on the extent and location of scarring that results from catheter ablation and its role in suppressing atrial fibrillation (AF). We examined the effect of atrial fibrosis and ablation induced scarring on catheter ablation outcomes in AF. Methods: We conducted a prospective multicenter study that enrolled 329 AF patients presenting for catheter ablation. Delayed enhancement magnetic resonance imaging (DE-MRI) of the left atrium was obtained pre-ablation. Scarring was evaluated in 177 patients with a DE-MRI scan obtained 90 days post-ablation. We evaluated residual fibrosis, defined as pre-ablation atrial fibrosis not covered by ablation scar. The primary outcome was freedom from recurrent atrial arrhythmia. Results: In the analysis cohort of 177 patients, pre-ablation fibrosis was 18.7±8.7% of the atrial wall. Ablation aimed at pulmonary vein (PV) isolation was performed in 163 patients (92.1%). Ablation-induced scar averaged 10.6±4.4% of the atrial wall. Scarring completely encircled all 4 PVs only in 12 patients (7.3%). Residual fibrosis was calculated at 15.8 ± 8.0%. At 325 days follow-up 35% of patients experienced recurrent arrhythmia. Multivariable Cox proportional hazards models demonstrated that baseline atrial fibrosis (HR and 95%
JAMA
IMPORTANCE Ablation of persistent atrial fibrillation (AF) remains a challenge. Left atrial fibrosis plays an important role in the pathophysiology of AF and has been associated with poor procedural outcomes. OBJECTIVE To investigate the efficacy and adverse events of targeting atrial fibrosis detected on magnetic resonance imaging (MRI) in reducing atrial arrhythmia recurrence in persistent AF. DESIGN, SETTING, AND PARTICIPANTS The Efficacy of Delayed Enhancement-MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation of Atrial Fibrillation trial was an investigator-initiated, multicenter, randomized clinical trial involving 44 academic and nonacademic centers in 10 countries. A total of 843 patients with symptomatic or asymptomatic persistent AF and undergoing AF ablation were enrolled from July 2016 to January 2020, with follow-up through February 19, 2021. INTERVENTIONS Patients with persistent AF were randomly assigned to pulmonary vein isolation (PVI) plus MRI-guided atrial fibrosis ablation (421 patients) or PVI alone (422 patients). Delayed-enhancement MRI was performed in both groups before the ablation procedure to assess baseline atrial fibrosis and at 3 months postablation to assess for ablation scar. MAIN OUTCOMES AND MEASURES The primary end point was time to first atrial arrhythmia recurrence after a 90-day blanking period postablation. The primary safety composite outcome was defined by the occurrence of 1 or more of the following events within 30 days postablation: stroke, PV stenosis, bleeding, heart failure, or death. RESULTS Among 843 patients who were randomized (mean age 62.7 years; 178 [21.1%] women), 815 (96.9%) completed the 90-day blanking period and contributed to the efficacy analyses. There was no significant difference in atrial arrhythmia recurrence between groups (fibrosis-guided ablation plus PVI patients, 175 [43.0%] vs PVI-only patients, 188 [46.1%]; hazard ratio [HR], 0.95 [95% CI, 0.77-1.17]; P = .63). Patients in the fibrosis-guided ablation plus PVI group experienced a higher rate of safety outcomes (9 [2.2%] vs 0 in PVI group; P = .001). Six patients (1.5%) in the fibrosis-guided ablation plus PVI group had an ischemic stroke compared with none in PVI-only group. Two deaths occurred in the fibrosis-guided ablation plus PVI group, and the first one was possibly related to the procedure. CONCLUSIONS AND RELEVANCE Among patients with persistent AF, MRI-guided fibrosis ablation plus PVI, compared with PVI catheter ablation only, resulted in no significant difference in atrial arrhythmia recurrence. Findings do not support the use of MRI-guided fibrosis ablation for the treatment of persistent AF.
Heart, 2011
Background Left atrial (LA) dilatation is an important risk factor for recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). However, the clinical applications to select patients eligible for RFCA according to LA size is limited. Additional pre-procedural assessment of LA fibrosis might improve patient selection for RFCA. Objective To investigate the impact of LA size and LA fibrosis on the outcome of RFCA for AF. Methods One hundred and seventy consecutive patients undergoing RFCA for AF were studied. LA size was assessed by measuring maximum LA volume index on echocardiography. LA wall ultrasound reflectivity was assessed by measuring echocardiography-derived calibrated integrated backscatter (IBS) as a surrogate of LA fibrosis. Results After 1263 months' follow-up, 103 patients (61%) had maintained sinus rhythm and 67 patients (39%) had recurrence of AF. Univariate Cox analyses identified LA wall ultrasound reflectivity, as well as LA size and type of AF, as predictors of AF recurrence after RFCA. Importantly, multivariate analyses showed that LA wall ultrasound reflectivity remained a strong predictor after correction for LA size and type of AF. Moreover, LA wall ultrasound reflectivity provided an incremental value in predicting outcome of RFCA over LA size and type of AF (increment in global c 2 ¼61.6, p<0.001). Conclusion Assessment of LA fibrosis using twodimensional echocardiography-derived calibrated IBS can be useful to predict AF recurrence after RFCA. Combined assessment of LA wall ultrasound reflectivity and LA size improves the identification of patients with a high likelihood for a successful ablation.
Circulation. Arrhythmia and electrophysiology, 2010
We evaluated scar lesions after initial and repeat catheter ablation of atrial fibrillation (AF) and correlated these regions to low-voltage tissue on repeat electroanatomic mapping. We also identified gaps in lesion sets that could be targeted and closed during repeat procedures. One hundred forty-four patients underwent AF ablation and received a delayed-enhancement MRI at 3 months after ablation. The number of pulmonary veins (PV) with circumferential lesions were assessed and correlated with procedural outcome. Eighteen patients with AF recurrence underwent repeat ablation. MRI scar regions were compared with electroanatomic maps during the repeat procedure. Regions of incomplete scar around the PVs were then identified and targeted during repeat ablation to ensure complete circumferential lesions. After the initial procedure, complete circumferential scarring of all 4 PV antrum (PVA) was achieved in only 7% of patients, with the majority of patients (69%) having <2 completel...
Background: Studies have shown that the presence of left atrial (LA) fibrosis can be assessed by LA delayed-enhancement cardiac magnetic resonance (LA DE-CMR) and may be predictive of outcome after ablation for atrial fibrillation (AF). We sought to test the hypothesis that the amount of LA fibrosis evaluated by DE-CMR correlates with the difficulty of complex fractionated atrial electrograms (CFAE) ablation. Methods: Twenty-two consecutive patients (86.4% nonparoxysmal AF) underwent substrate CFAE radiofrequency (RF) ablation (±Pulmonary veins isolation) with AF termination as the endpoint. LA DE-CMR was performed prior to ablation. A global index of DE was defined by an average of six LA segmental scores based on a four-grade scale (no enhancement to maximum enhancement). Time between first RF application and AF termination, and RF duration until AF termination, was recorded. CFAE area/total LA surface was also measured on CARTO maps (Biosense Webster, Diamond Bar, CA, USA). These measures served to evaluate ablation difficulty, and were correlated with CMR images by double-blinded analysis. Results: Ablation restored sinus rhythm in 20 of 22 patients (91%), with a time to terminate AF of 140 ± 91 minutes. There was a significant correlation between the global averaged DE-CMR fibrosis grade and the electrophysiological substrate indexes such as “time to terminate AF” (Rho = 0.70, P = 0.0003), “RF duration until AF termination” (Rho = 0.65, P = 0.001), and a trend toward correlation with “CFAE area/LA surface” (Rho = 0.47, P = 0.03). Conclusions: LA DE-CMR can predict increased difficulty of CFAE ablation in AF. This tool may be beneficial in both selection of patients and ablation strategy. (PACE 2011; 34:1267–1277)
Left atrial fibrosis progression detected by LGE‐MRI after ablation of atrial fibrillation
Pacing and Clinical Electrophysiology, 2019
Background: Left atrial (LA) fibrosis is thought to be a substrate for atrial fibrillation (AF) and can be quantified by late gadolinium enhancement magnetic resonance imaging (LGE-MRI). Fibrosis formation in LA is a dynamic process and may either progress or regress following AF ablation. We examined the impact of post-ablation progression in LA fibrosis on AF recurrence. Methods: LA enhancement in LGE-MRI was quantified in 127 consecutive patients who underwent first time AF ablation. Serial LGE-MRIs were done prior to AF ablation, 3 months post-ablation and at least 12 months after second LGE-MRI. Transient post-ablation lesion (TL) was defined as atrial enhancement caused by ablation lesions that was detected on the first (3 month) but not on the second post-ablation LGE-MRI. New fibrosis (NF) was defined as atrial enhancement detected on the most recent LGE-MRI, at least 15 months after the ablation procedure. AF recurrence and its correlation with TL and NF was assessed in all patients during the follow-up period. Results: An increase of 1% NF increased the chance of post-ablation AF recurrence by 3% (HR 1.03, 95% CI 1-1.06, p = 0.05). TL had no significant impact on recurrence (p =0.057). After adjusting for cardiovascular risk factors, HR increased as NF became greater. Greater volume of NF (≥ 21%) corresponded with lower arrhythmia free survival (37% vs 62%, p = 0.01). Conclusion: NF formation post-ablation of AF is a novel marker of long-term procedural outcome. Extensive NF is associated with significantly higher risk of atrial arrhythmia recurrence.