An artificial intelligence-enabled electrocardiogram algorithm for the prediction of left atrial low-voltage areas in persistent atrial fibrillation

OBJECTIVES

We aimed to construct an artificial intelligence-enabled electrocardiogram (ECG) algorithm that can accurately predict the presence of left atrial low-voltage areas (LVAs) in patients with persistent atrial fibrillation.

METHODS

The study included 587 patients with persistent atrial fibrillation who underwent catheter ablation procedures between March 2012 and December 2023 and 942 scanned images of 12-lead ECGs obtained before the ablation procedures were performed. Artificial intelligence-based algorithms were used to construct models for predicting the presence of LVAs. The DR-FLASH and APPLE clinical scores for LVA prediction were calculated. We used a receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis to evaluate model performance.

RESULTS

The data obtained from the participants were split into training (n = 469), validation (n = 58), and test sets (n = 60). LVAs were detected in 53.7% of all participants. Using ECG alone, the deep learning algorithm achieved an area under the ROC curve (AUROC) of 0.752, outperforming both the DR-FLASH score (AUROC = 0.610) and the APPLE score (AUROC = 0.510). The random forest classification model, which integrated a probabilistic deep learning model and clinical features, showed a maximum AUROC of 0.759. Moreover, the ECG-based deep learning algorithm for predicting extensive LVAs achieved an AUROC of 0.775, with a sensitivity of 0.816 and a specificity of 0.896. The random forest classification model for predicting extensive LVAs achieved an AUROC of 0.897, with a sensitivity of 0.862, and a specificity of 0.935.

CONCLUSION

The deep learning model based exclusively on ECG data and the machine learning model that combined a probabilistic deep learning model and clinical features both predicted the presence of LVAs with a higher degree of accuracy than the DR-FLASH and the APPLE risk scores.

Characterization of patients with extensive left atrial myopathy referred for atrial fibrillation ablation: incidence, predictors, and outcomes

BACKGROUND

Although atrial fibrosis has a relevant impact on ablation success rate, experimental studies have reported that extensive fibrosis may be accompanied by a reduced burden secondary to a prominent depression of atrial excitability.

OBJECTIVES

We aimed to identify clinical and echocardiographic factors associated with extensive left atrial myopathy (ELAM), to analyze the predictive ability of established scores (AF score, APPLE, and DR-FLASH) and assess outcomes in terms of AF recurrence, left atrial flutter, and post-procedural heart failure admissions.

METHODS

A total of 950 consecutive patients undergoing the first AF ablation were included. A 3D electroanatomical mapping system (CARTO3, Biosense Webster) was created using a multipolar mapping catheter (PentaRay, Biosense Webster). ELAM was defined as ≥ 50% low voltage area. A subanalysis with four groups was also created (< 10%; 10-20%; 10-20%; and > 30%). Logistic regressions, Cox proportional hazards models, and log-rank test were used to test the predictors independently associated with the presence of ELAM and AF recurrence. The model was prospectively validated in a cohort of 150 patients obtaining an excellent ability for prediction AUC 0.90 (CI 95% 0.84-0.96).

RESULTS

Overall, 78 (8.42%) presented ELAM. Age, female sex, persistent AF, first-degree AV block, and E/e' were significant predictors. The model incorporating these factors outperformed the existing scores (AUC = 0.87). During a mean follow-up of 20 months (IQR 9 to 36), patients with ELAM presented a higher rate of AF recurrence (42.02% vs 26.01%, p = 0.030), left atrial flutter (26.03% vs 8.02%, p < 0.001), and post-procedural heart failure admissions (12.01% vs 0.61%, p < 0.001) than non-ELAM patients.

CONCLUSIONS

This study reveals the incidence and clinical factors associated with ELAM in AF, highlighting age, female, persistent AF, first-degree AV block, and E/e'. Importantly, the presence of ELAM is associated with poorer outcomes in terms of recurrence and HF admission.

P-wave duration as a marker of atrial remodeling in patients referred to ablation for atrial fibrillation: A new stratification tool emerging?

Ablation of atrial fibrillation is one of the most widely applied invasive procedures in cardiovascular medicine, and populations with atrial fibrillation continuously rise. Recurrence rates are, however, consistently high, even in patients without severe comorbidities. Robust stratification algorithms to distinguish patients suitable for ablation are generally lacking. This is a fact caused by the inability to incorporate evidence of atrial remodeling and fibrosis, e.g., atrial remodeling, in the decision pathways. Cardiac magnetic resonance is a powerful tool in identifying fibrosis; however, it is costly and not routinely used. Electrocardiography has been generally underutilized in clinical practice during pre-ablative screening. One of the characteristics of the electrocardiogram that can give us valuable data depicting the existence and the extent of atrial remodeling and fibrosis is the duration of the P-wave. Currently, many studies support the implementation of P-wave duration in the routine practice of patient evaluation as a surrogate marker of existing atrial remodeling, that in turn predicts recurrence after ablation of atrial fibrillation. Further research is guaranteed to establish this electrocardiographic characteristic in our stratification quiver.

Sex-Related Differences in Left Atrial Low-Voltage Areas According to CHA2DS2-VA Scores among Patients with Atrial Fibrillation

(1) Background: We hypothesized that female sex would have a differential impact on left atrial (LA) low-voltage areas (LVAs) according to CHA2DS2-VA scores. (2) Methods: This study included 553 patients who underwent radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). LVAs were defined as regions with bipolar peak-to-peak voltages of <0.5 mV. The proportion of LVAs was calculated by dividing the total LVA by the LA surface area. (3) Results: There was no sex-related difference in LA LVAs among patients with a CHA2DS2-VA scores ≤ 2. The proportion of LVAs was significantly higher in females among patients with CHA2DS2-VA scores of 3 or 4 (10.1 (4.7−15.1)% vs. 15.8 (9.2−32.1)%; p = 0.027). Female sex was significantly associated with extensive LVAs (LVA proportion ≥ 30%). Females had odd ratios of 27.82 (95% confidence interval (CI) 3.33−756.8, p = 0.01), and 1.53 (95% CI 0.81−2.83, p = 0.184) for extensive LAVs in patients with CHA2DS2-VA scores ≥ 3 and CHA2DS2-VA scores < 3, respectively. In the multiple regression model, female patients with a CHA2DS2-VA ≥3 were significantly associated with a higher proportion of LVAs (β = 8.52, p = 0.039). (4) Conclusions: Female sex was significantly associated with extensive LVAs, particularly when their CHA2DS2-VA scores were ≥3. This result suggests that female sex has a differential effect on the extent of LVAs based on the presence of additional risk factors.

Determinants of fibrotic atrial cardiomyopathy in atrial fibrillation. A multicenter observational study of the RETAC (reseau européen de traîtement d'arrhythmies cardiaques)-group

Aims

Despite advances in interventional treatment strategies, atrial fibrillation (AF) remains associated with significant morbidity and mortality. Fibrotic atrial myopathy (FAM) is a main factor for adverse outcomes of AF-ablation, but complex to diagnose using current methods. We aimed to derive a scoring system based entirely on easily available clinical parameters to predict FAM and ablation-success in everyday care.

Methods

In this multicenter, prospective study, a new risk stratification model termed AF-SCORE was derived in 220 patients undergoing high-density left-atrial(LA) voltage-mapping to quantify FAM. AF-SCORE was validated for FAM in an external mapping-validation cohort (n = 220) and for success following pulmonary vein isolation (PVI)-only (without adjunctive left- or right atrial ablations) in an external outcome-validation cohort (n = 518).

Results

FAM was rare in patients < 60 years (5.4%), but increased with ageing and affected 40.4% (59/146) of patients ≥ 60 years. Sex and AF-phenotype had additional predictive value in older patients and remained associated with FAM in multivariate models (odds ratio [OR] 6.194, p < 0.0001 for ≥ 60 years; OR 2.863, p < 0.0001 for female sex; OR 41.309, p < 0.0001 for AF-persistency). Additional clinical or diagnostic variables did not improve the model. AF-SCORE (+ 1 point for age ≥ 60 years and additional points for female sex [+ 1] and AF-persistency [+ 2]) showed good discrimination to detect FAM (c-statistic 0.792) and predicted arrhythmia-freedom following PVI (74.3%, 54.7% and 45.5% for AF-SCORE ≤ 2, 3 and 4, respectively, and hazard ratio [HR] 1.994 for AF-SCORE = 3 and HR 2.866 for AF-SCORE = 4, p < 0.001).

Conclusions

Age, sex and AF-phenotype are the main determinants for the development of FAM. A low AF-SCORE ≤ 2 is found in paroxysmal AF-patients of any age and younger patients with persistent AF irrespective of sex, and associated with favorable outcomes of PVI-only. Freedom from arrhythmia remains unsatisfactory with AF-SCORE ≥ 3 as found in older patients, particularly females, with persistent AF, and future studies investigating adjunctive atrial ablations to PVI-only should focus on these groups of patients.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01973-1.

Mitral valve regurgitation is associated with left atrial fibrosis in patients with atrial fibrillation

BACKGROUND

Low voltage zones (LVZ) are associated with poor outcomes in patients with atrial fibrillation (AF). The APPLE and DR-FLASH scores predict LVZ in patients undergoing catheter ablation. This study aimed to assess the relationship of mitral valve regurgitation (MR) and LVZ after adjusting for APPLE or DR-FLASH scores.

METHODS

This was a retrospective study on patients with AF who underwent their first catheter ablation. All patients underwent a transthoracic echocardiographic examination before ablation. The APPLE and DR-FLASH scores were calculated at baseline. LVZ determined by high-density mapping was defined as bipolar voltage amplitude <0.5 mV. LVZ presence was defined as LVZ covering >5% of the left atrial surface area.

RESULTS

Altogether, 152 patients (mean age 62.0 ± 10.8 years, 65.8% men, and 36.2% with persistent AF) were included. Of the 152 patients, 47 (30.9%) had LVZ. The patients with LVZ had more moderate-to-severe MR (17.0% vs. 3.8%, P = 0.014) and higher APPLE scores (1.7 ± 1.1 vs. 1.2 ± 1.1, P = 0.009) and DR-FLASH scores (3.0 ± 1.5 vs. 2.4 ± 1.4, P = 0.010). Using multivariate logistic regression analysis, we found moderate-to-severe MR was related to LVZ presence after adjusting for the APPLE (OR 4.040, P = 0.034) or DR-FLASH (OR 4.487, P = 0.020) scores. Furthermore, moderate-to-severe MR had an incremental predictive value for LVZ presence in addition to the APPLE (P = 0.03) or DR-FLASH (P = 0.02) scores.

CONCLUSION

In patients with AF, MR severity was related to LVZ after adjusting the APPLE score or DR-FLASH score.

Biatrial volume ratio predicts low voltage areas in atrial fibrillation

BACKGROUND

Left atrial volume (LAV) and low voltage areas (LVAs) are acknowledged markers for worse rhythm outcome after ablation of atrial fibrillation (AF). Some studies reported the importance of increased right atrial volume (RAV) as a predictor for arrhythmia recurrences in AF patients.

OBJECTIVE

To investigate association between the LAV/RAV ratio and LVAs presence.

METHODS

Patients undergoing first AF ablation were included. LVAs were assessed peri-procedurally using high-density 3D maps and defined as <0.5 mV. All patients underwent pre-procedural cardiovascular magnetic resonance imaging. LAV (biplane) and RAV (monoplane 4-chamber) were assessed prior to ablation, and the LAV/RAV ratio was calculated.

RESULTS

The study population included 189 patients (age mean 63 ± 10 years, 33% women, 57% persistent AF, 22% LVAs). There were 149 (79%) patients with LAV > RAV. In univariable analysis LAV > RAV was associated with LVAs (OR 6.803, 95%CI 1.395-26.514, p = .016). The association remained robust in multivariable model after adjustment for persistent AF, CHA₂ DS₂ -VASc score, and heart rate (OR 5.981, 95%CI 1.256-28.484, p = .025). Using receiver operator curve analysis, LAV > RAV (AUC 0.668, 95%CI 0.585-0.751, p = .001) was significant predictor for LVAs. In multivariable analysis, after adjustment for age, persistent AF, and renal function, RAV≥LAV was threefold higher in males (OR 3.040, 95%CI 1.050-8.802, p = .04).

CONCLUSIONS

LAV > RAV is useful for the prediction of electro-anatomical substrate in AF. LAV > RAV was associated with LVAs presence, while male sex remained associated with RAV≥LAV and less LVAs.

Prediction of low-voltage areas using modified APPLE score

AIMS

The presence of low-voltage areas (LVAs) in patients with atrial fibrillation (AF) reflects left atrial (LA) electroanatomical substrate, which is essential for individualized AF management. However, echocardiographic anteroposterior LA diameter included into previous LVAs prediction scores does not mirror LA size accurately and impaired left ventricular ejection fraction (LV-EF) is not directly associated with atrial myopathy. Therefore, we aimed to compare a modified (m)APPLE score, which included LA volume (LAV) and LA emptying fraction (LA-EF) with the regular APPLE score for the prediction of LVAs.

METHODS AND RESULTS

In patients undergoing first AF catheter ablation, LVAs were determined peri-interventionally using high-density maps and defined as signal amplitude <0.5 mV. All patients underwent cardiovascular magnetic resonance imaging before intervention. The APPLE (one point for Age ≥ 65 years, Persistent AF, imPaired eGFR ≤ 60 mL/min/1.73 m2, LA diameter ≥ 43 mm, and LVEF < 50%) and (m)APPLE (last two variables changed by LAV ≥ 39 mL/m2, and LA-EF < 31%) scores were calculated at baseline. The study population included 219 patients [median age 65 (interquartile range 57-72) years, 41% females, 59% persistent AF, 25% LVAs]. Both scores were significantly associated with LVAs [OR 1.817, 95% CI 1.376-2.399 for APPLE and 2.288, 95% CI 1.650-3.172 for (m)APPLE]. Using receiver operating characteristic curves analysis, the (m)APPLE score [area under the curve (AUC) 0.779, 95% CI 0.702-0.855] showed better LVAs prediction than the APPLE score (AUC 0.704, 95% CI 0.623-0.784), however, without statistically significant difference (P = 0.233).

CONCLUSION

The modified (m)APPLE score demonstrated good prognostic value for LVAs prediction and was comparable with the regular APPLE score.

Easily available ECG and echocardiographic parameters for prediction of left atrial remodeling and atrial fibrillation recurrence after pulmonary vein isolation: A multicenter study

BACKGROUND

The assessment of noninvasive markers of left atrial (LA) low-voltage substrate (LVS) enables the identification of atrial fibrillation (AF) patients at risk for arrhythmia recurrence after pulmonary vein isolation (PVI).

METHODS

In this prospective multicenter study, 292 consecutive AF patients (72% male, 62 ± 11 years, 65% persistent AF) underwent high-density LA voltage mapping in sinus rhythm. LA-LVS (<0.5 mV) was considered as significant at 2 cm²  or above. Preprocedural clinical electrocardiogram and echocardiographic data were assessed to identify predictors of LA-LVS. The role of the identified LA-LVS markers in predicting 1-year arrhythmia freedom after PVI was assessed in 245 patients.

RESULTS

Significant LA-LVS was identified in 123 (42%) patients. The amplified sinus P-wave duration (APWD) best predicted LA-LVS, with a 148-ms value providing the best-balanced sensitivity (0.81) and specificity (0.88). An APWD over 160 ms was associated with LA-LVS in 96% of patients, whereas an APWD under 145 ms in 15%. Remaining gray zones improved their accuracy by introduction of systolic pulmonary artery pressure (sPAP) of 35 mmHg or above, age, and sex. According to COX regression, the risk of arrhythmia recurrence 12 months following PVI was twofold and threefold higher in patients with APWD 145-160 and over 160 ms, compared to APWD under 145 ms. Integration of pulmonary hypertension further improved the outcome prediction in the intermediate APWD group: Patients with APWD 145-160 ms and normal sPAP had similar outcome than patients with APWD under 145 ms (hazard ratio [HR] 1.62, p = .14), whereas high sPAP implied worse outcome (HR 2.56, p < .001).

CONCLUSIONS

The APWD identifies LA-LVS and risk for arrhythmia recurrence after PVI. Our prediction model becomes optimized by means of integration of the pulmonary artery pressure.

Responsiveness to bepridil predicts atrial substrate in patients with persistent atrial fibrillation

BACKGROUND

The low voltage zone (LVZ) detected with three-dimensional electroanatomical mapping is a surrogate marker of atrial scar in patients with persistent atrial fibrillation (PeAF) and is associated with poor clinical outcomes after catheter ablation. However, fewer studies have reported the relationship between responsiveness to antiarrhythmic drugs and the LVZ.

METHODS

We retrospectively analyzed 76 patients who underwent catheter ablation for PeAF at our center. Rhythm control with bepridil was initiated before ablation in all patients, and electrical cardioversion was performed in cases of failure to restore sinus rhythm with bepridil alone. Patients with successful sinus restoration with bepridil alone (≤200 mg/d) were defined as "responders", while those who required electrical cardioversion as well were defined as "non-responders". We compared the LVZ ratio (ratio of the LVZ surface area to the left atrium surface area on three-dimensional electroanatomical mapping) and the recurrence-free rate after ablation between the two groups.

RESULTS

Of the 76 patients, 48 (63.2%) were responders to bepridil. The median LVZ ratio was significantly lower in the responder group than in the nonresponder group (7.5% vs 14.0%, P = .009). Multivariate analysis revealed that response to bepridil was an independent predictor of normal voltage (P = .02, odds ratio = 0.20, 95% confidence interval = 0.04-0.76). The recurrence-free rate at 1 year after catheter ablation was significantly higher in the responder group than in the nonresponder group (87.1% vs 62.3%, P = .03).

CONCLUSIONS

Response to bepridil is a marker of normal voltage in electroanatomical mapping and is significantly associated with better clinical outcomes after catheter ablation.

Are the atrial natriuretic peptides a missing link predicting low-voltage areas in atrial fibrillation? Introducing the novel biomarker-based atrial fibrillation substrate prediction (ANP) score

BACKGROUND

In patients with atrial fibrillation (AF), left atrial (LA) enlargement, and the presence of low-voltage areas (LVAs) indicate an advanced disease stage. NT-proANP is a biomarker, which is significantly higher in both phenotypes. Prediction of LVAs before catheter ablation could impact the prognosis and therapeutical management in AF patients.

OBJECTIVE

The aim of this study was to (a) analyze the predictive value of a novel biomarker-based AF substrate prediction score, and (b) compare it with DR-FLASH and APPLE scores.

METHODS

Patients undergoing first AF catheter ablation were included. LA volume (LAV) was analyzed prior to ablation using cardiovascular magnetic resonance imaging (CMR). Blood plasma samples from the femoral vein were collected before AF ablation. NT-proANP was analyzed using commercially available assays. LVAs were determined using high-density maps during catheter ablation and defined as <0.5 mV. The novel ANP score (one point for Age ≥ 65 years, NT-proANP > 17 ng/mL, and Persistent AF) was calculated at baseline.

RESULTS

The study population included 156 AF patients (64 ± 10 years, 65% males, 61% persistent AF, 28% LVAs). The cut-off ANP score ≥ 2 demonstrated 77% sensitivity and 70% specificity. On logistic regression (odds ratio [OR] 3.469) and receiver operating characteristic (ROC) analysis (area under the curve [AUC] 0.778, P < .001), the ANP score significantly predicted LVAs presence. There were no differences between novel ANP score - which is a new one - is described in the Abstract; with APPLE (AUC 0.718, P = .378) and DR-FLASH (AUC 0.766, P = .856) scores.

CONCLUSIONS

The novel biomarker-based ANP score demonstrates good prediction of LVAs.

Predictors of Recurrence of AF in Patients After Radiofrequency Ablation

Catheter ablation is a well-known treatment for patients with AF. Despite the growing knowledge in the field, the identification of predictors of recurrence of AF after catheter ablation is one of the primary goals and is of major importance to improve long-term results of the procedure. The aim of this article is to provide an overview of what has been published in recent years and to summarise the major predictors, helping cardiac electrophysiologists in the selection of the right candidates for catheter ablation.

Predicting atrial fibrillation recurrence after ablation in patients with heart failure: Validity of the APPLE and CAAP-AF risk scoring systems

BACKGROUND

Compared with medical therapy, catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) improves cardiovascular outcomes. Risk scores (CAAP-AF and APPLE) have been developed to predict the likelihood of AF recurrence after ablation, have not been validated specifically in patients with AF and HF.

METHODS

We analyzed baseline characteristics, risk scores, and rates of AF recurrence 12 months postablation in a cohort of 230 consecutive patients with AF and HF undergoing PVI in the Duke Center for Atrial Fibrillation registry from 2009-2013.

RESULTS

During a follow-up period of 12 months, 76 of 230 (33%) patients with HF experienced recurrent AF after ablation. The median APPLE and CAAP-AF scores were 1.5 ([Q1, Q3]: [1.0, 2.0]) and 4.0 ([Q1, Q3]: [3.0, 5.0]), respectively and were not different from those patients with and without recurrent AF. Freedom from AF was not different according to APPLE and CAAP-AF scores. Discrimination for recurrent AF with the CAAP-AF score was modest with a C-statistic of 0.60 (95% CI 0.52-0.67). Discrimination with the APPLE score was similarly modest, with a C-statistic of 0.54 (95% CI: 0.47-0.62).

CONCLUSIONS

Validated predictive risk scores for recurrent AF after catheter ablation exhibit limited predictive ability in cohorts of AF and HF. Additional tools are needed to facilitate risk stratification and patient selection for AF ablation in patients with concomitant HF.

Left atrial size and total atrial emptying fraction in atrial fibrillation progression

BACKGROUND

Left atrial (LA) size and low-voltage areas (LVA) mirror atrial fibrillation (AF) progression. Whether these factors are important for the impairment of total atrial emptying fraction is understudied.

OBJECTIVE

The aim of the present analysis was to investigate the association between LA volume and total atrial emptying fraction with AF progression phenotypes: persistent AF and LVA.

METHODS

Patients undergoing first AF ablation were included in the analysis. LVA were determined using high-density maps and defined as <0.5 mV. All patients underwent cardiovascular magnetic resonance imaging before the intervention. Cardiovascular magnetic resonance data (LA volume, LA emptying fraction [LA-EF], and right atrial emptying fraction [RA-EF]) were measured in all patients.

RESULTS

The study population included 211 patients (65 ± 11 years; 124 (59%) men; 122 (58%) persistent AF; 54 (26%) LVA). There were 4 disease progression groups: paroxysmal AF without LVA, paroxysmal AF with LVA, persistent AF without LVA, and persistent AF with LVA. While LA volume increased according to the AF progression phenotype (98 ± 27, 145 ± 34, 134 ± 41, 141 ± 39 mL, respectively; P < .001), total LA-EF (51% ± 17%, 32% ± 17%, 33% ± 17%, 22% ± 11%; P < .001) and RA-EF (47% ± 13%, 36% ± 17%, 30% ± 16%, 23% ± 12%; P < .001) decreased. In multivariable analysis, age (odds ratio [OR] 1.084; 95% confidence interval [CI] 1.028-1.142; P = .003), persistent AF (OR 3.478; 95% CI 1.117-10.830; P = .031), and total LA-EF (OR 0.933; 95% CI 0.899-0.968; P < .001) showed a significant association for LVA. Using receiver operating characteristic curve analysis, LA-EF (area under the curve 0.778; 95% CI 0.711-0.846; P < .001) and RA-EF (area under the curve 0.726; 95% CI 0.650-0.802; P < .001) were significantly associated with the absence of LVA.

CONCLUSION

LVA and persistent AF are associated with worse total atrial emptying fraction.

Clinical scores used for the prediction of negative events in patients undergoing catheter ablation for atrial fibrillation

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia in adults. Catheter ablation (CA) is one of the most important management strategies to reduce AF burden and AF-associated complications. In order to stratify the risk of adverse events and to predict treatment success in AF patients undergoing CA, several risk stratification scores had been developed during the last decade. The aim of this review is to provide an overview of the most important clinical risk scores predicting rhythm outcomes, electro-anatomical substrate and mortality in AF.

Association Between Cardiovascular Magnetic Resonance-Derived Left Atrial Dimensions, Electroanatomical Substrate and NT-proANP Levels in Atrial Fibrillation

Background Enlargement of left atrial ( LA ) size indicates advanced disease stage in patients with atrial fibrillation ( AF ) and is associated with poor success of different AF therapies. Two dimensional echocardiographic LA measurements do not reliably reflect the true size of LA anatomy. The aim of the current study was: 1) to analyze cardiovascular magnetic resonance ( CMR )-derived LA dimensions and their association with low voltage areas ( LVA ); and 2) to investigate the association between these parameters and NT -pro ANP (N-terminal proatrial natriuretic peptide) levels. Methods and Results Patients undergoing first AF catheter ablation were included. All patients underwent CMR imaging (Ingenia 1.5T Philips) before intervention. CMR data ( LA volume, superior-inferior, transversal and anterior-posterior LA diameters) were measured in all patients. LVA were determined using high-density maps and a low voltage threshold <0.5 mV. Blood plasma samples from femoral vein were collected before catheter ablation. NT -pro ANP levels were studied using commercially available assays. There were 216 patients (65±11 years, 59% males, 56% persistent AF , 26% LVA ) included into analyses. NT -pro ANP levels in patients with LVA were significantly higher than in those without (median/interquartile range 22 [13-29] versus 15 [9-22] pg/mL, P=0.004). All CMR derived LA diameters correlated significantly with persistent AF ( r²=0.291-0.468, all P<0.001), LVA ( r²=0.187-0.306, all P<0.001), and NT -pro ANP levels ( r²=0.258-0.352, P<0.01). On logistic regression multivariable analysis, age (odds ratio=1.090, 95% confidence interval: 1.030-1.153, P=0.003), females (odds ratio=2.686, 95% confidence interval: 1.047-6.891, P=0.040), and LA volume (odds ratio=1.022, 95% confidence interval: 1.009-1.035, P=0.001) remained significant predictors for LVA . Conclusions Left atrial CMR parameters are associated with persistent AF , low voltage areas and NT -pro ANP levels. LA volume is the most significant predictor for LVA .

Prediction of electro-anatomical substrate and arrhythmia recurrences using APPLE, DR-FLASH and MB-LATER scores in patients with atrial fibrillation undergoing catheter ablation

Arrhythmia recurrences after catheter ablation of atrial fibrillation (AF) cause intensive treatment costs. Left atrial electro-anatomical remodeling measured as low voltage areas (LVA) during catheter ablation indicates advanced disease stage and is associated with poor ablation success. The aim of this study was to analyze the prediction of LVA and arrhythmia recurrences using APPLE, DR-FLASH and MB-LATER scores. APPLE, DR-FLASH scores were calculated at baseline and MB-LATER at 3 months post-ablation in AF patients undergoing first catheter ablation. LVA was determined using high-density maps and defined as <0.5 mV. Early (ERAF, <3 months) and late (LRAF, 3–12 months) were analyzed during follow-up. The study population included 241 patients (age 64 ± 11 years, 59% males, 59% persistent AF, 27% LVA, 27% LRAF). LVA were significantly associated with recurrences (OR 2.081, p = 0.026). While on univariable analysis, all scores were significantly associated with LVA, on multivariable analysis only APPLE (OR 1.789, p < 0.001) and DR-FLASH (OR 2.144, p < 0.001) remained significant predictors. However, MB-LATER (OR 1.445, p = 0.034) and ERAF (OR 5.078, p < 0.001) remained associated with LRAF on the multivariable analysis. These results were validated in a subgroup of 873 patients (age 61 ± 10, 63% males, 39% persistent AF, 34% LRAF, 27% LVA) from The Leipzig Heart Center AF Ablation Registry. All scores were significantly associated with recurrences. However, ERAF was the most powerful predictor for later rhythm outcomes. Summarizing, a clinical score useful for prediction for both LVA and rhythm outcomes in AF patients remains a clinical unmet need.