Temporary Trends Concerning the Extent and Efficacy of Atrial Fibrillation Ablation Using Radiofrequency Energy in a Polish Single-Center Experience.

Background and Objectives: Atrial fibrillation (AF) is the most common supraventricular arrhythmia. Currently, catheter ablation is a preferred treatment strategy. The main objective of our study was a temporary trends analysis of patients' data undergoing a single AF ablation procedure using radiofrequency energy (RF). The efficacy of the procedure underwent assessment during a 12-month follow-up. Materials and Methods: We analyzed 585 consecutive patients with symptomatic, recurrent, and drug-refractory AF hospitalized in our department between 2013 and 2018 who underwent RF ablation supported by a 3D electroanatomical system. The baseline characteristics, periprocedural parameters, and efficacy of the procedure at 6-, 9- and 12-month follow-ups were analyzed over the years. Results: The number of patients undergoing ablation increased. Patients with paroxysmal AF predominated (71.5%). However, the number of patients with the persistent type of arrhythmia increased over the years. The percentage of patients with chronic heart failure (CHF) increased to 27.5% in 2018, and patients presented with increasingly larger left atria (LA). In all patients, circumferential pulmonary vein isolation was performed. The percentage of patients who underwent arrhythmogenic substrate modification and cavotricuspid isthmus ablation increased. Over the years, the efficacy of a single procedure at the 12-month follow-up remained without significant differences between the years (72.0%, 69.6%, 75.5%, 74.8%, 71.7%, 71.7%). Conclusions: The rate of patients with CHF and advanced LA disease undergoing more extensive ablation increased over the years. The efficacy of a single procedure remained without significant differences between the years.

Impact of Remote Monitoring on Long-Term Prognosis in Heart Failure Patients in a Real-World Cohort: Results From All-Comers COMMIT-HF Trial.

BACKGROUND: Randomized controlled trials demonstrate that remote monitoring (RM) of implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy devices (CRT-Ds) may improve quality of care and prognosis in heart failure (HF) patients. However, the impact of RM on long-term mortality in a real-world cohort is still not well examined. METHODS AND RESULTS: This study was designed as a matched cohort study based on the COMMIT-HF trial--a single-center, ongoing prospective observational registry (NCT02536443). Complete patient demographics, medical history, in-hospital results, hospitalizations, and mortality data were collected based on institutional registries and healthcare providers' records. Patients were divided into 2 groups based on RM presence and matched by means of propensity scores according to clinical characteristics. The primary endpoint of this study was the long-term all-cause mortality. Out of 1,429 consecutive patients, 822 patients with a first implantation of an ICD/CRT-D were included in the analysis. The final matched study population contained 574 patients in RM and in a control group. Although demographic and echocardiographic parameters as well as pharmacological treatments were similar in both groups, a significantly lower 1-year mortality was detected in the RM group (2.1% vs. 11.5%, P < 0.0001). This was also maintained during a 3-year follow-up (4.9% vs. 22.3%, P < 0.0001). Multivariate analysis showed that RM was associated with an improved prognosis (hazard ratio 0.187, 95% confidence interval 0.075-0.467, P = 0.0003). CONCLUSION: RM of HF patients with ICDs/CRT-Ds significantly reduced long-term mortality in a real-world clinical condition.

Effect of Therapeutic Ionizing Radiation on Implantable Electronic Devices: Systematic Review and Practical Guidance.

Cardiac implantable electronic devices (CIEDs) have been in use for over 50 years and their therapeutic value is undisputable. With the rapidly aging population, it is estimated that the number of CIEDs will grow dramatically over the next 2 decades. Given these predictions, the topic of management of concomitant conditions associated with older age becomes more relevant than ever. In particular, the number of patients with an implanted CIED diagnosed with cancer is expected to rise by about 70%, from 14 million in 2012 to 22 million within the next 2 decades. Treatment of most of these tumors and tumor metastases requires radiation therapy. However, the necessary high doses of radiation can potentially interact with the function, longevity, and integrity of the CIEDs and/or cause harm to the patient. The impact of an absence of clear therapeutic guidelines for oncology patients with CIEDs who should undergo radiation therapy is vast; and due to the fear of possible complications related to device failure, many of these patients may not be treated adequately to their needs, which can strongly affect their prognosis. This article summarizes the available data on the management of patients with CIEDs undergoing radiotherapy. It systematically presents possible causes and consequences of direct and scattered radiation on CIEDs, highlights possible complications that may occur during this kind of treatment, and provides practical guidance for this challenging real life clinical setting.

Epicardial Pulsed Field Ablation of Ganglionated Plexi: Computational and Pre-Clinical Evaluation of a Bipolar Sub-Xiphoid Catheter for the Treatment of Atrial Fibrillation.

Epicardial pulsed field ablation (PFA) of ganglionated plexi (GPs) is being explored as a potential treatment for atrial fibrillation. Initial work using open-chest access with a monopolar ablation device has been completed. This study describes the early development work for a device that can be used with subxiphoid access and deliver bipolar ablation pulses. Electric field computational models have been used for the initial guidance on pulse parameters. An in vivo assessment of these ablation parameters has been performed in an open-chest canine study, while subxiphoid access and navigation of the device has been demonstrated in a porcine model. Results from this acute study have demonstrated the promising potential of this approach.

Changing coronary sinus activation during catheter ablation of isthmus-dependent right atrial flutter: what is the mechanism?

A 69-year-old woman was referred for cavotricuspid isthmus ablation due to typical isthmus-dependent right atrial flutter. During ablation, intracardiac activation sequence in coronary sinus (CS) changed without altering the cycle length or the P-wave morphology. This suggests that interatrial connection via CS was blocked and left atrium (LA) was activated from Bachmann's bundle or/and connections between fossa ovalis and LA.

Impact of Contact Force-Sensing Catheters on Fluoroscopy Time in Interventional Electrophysiology: A European Survey.

This multicenter European survey systematically evaluated the impact of using contact force-sensing catheters (CFSCs) on fluoroscopy and procedure time in interventional electrophysiology. Data from 25 participating centers were collected and analyzed, also considering important confounders. With the use of CFSCs, fluoroscopy time was reduced for right- and left-sided atrial ablations (median −6.4 to −9.6 min, p < 0.001 for both groups), whereas no such effect could be found for ventricular ablations. Moreover, the use of CFSCs was associated with an increase in procedure time for right-sided atrial and ventricular ablations (median +26.0 and +44.0 min, respectively, p < 0.001 for both groups), but not for left-sided atrial ablations. These findings were confirmed independent of career level and operator volume, except for very highly experienced electrophysiologists, in whom the effect was blunted. In the subset of pulmonary vein isolations (PVIs), CFSCs were shown to reduce both fluoroscopy and procedure time. In conclusion, the use of CFSCs was associated with a reduced fluoroscopy time for atrial ablations and an increased procedure time for right atrial and ventricular ablations. These effects were virtually independent of the operator experience and caseload. When considering only PVIs as an important subset, CFSCs were shown to reduce both fluoroscopy and procedure time.

De novo and pre-existing atrial fibrillation in acute coronary syndromes: impact on prognosis and cardiovascular events in long-term follow-up.

AIMS: The aim of the study was to compare in-hospital and long-term prognosis in patients with acute coronary syndromes (ACS) and de novo vs. pre-existing atrial fibrillation (AF). Atrial fibrillation increases the risk of serious adverse events including death in patients with ACS. However, it is unclear whether de novo and pre-existing AF portend a different risk. METHODS AND RESULTS: We analysed the incidence, clinical characteristics, and in-hospital and long-term outcomes in patients with AF and ACS based on combined data from Polish Registry of Acute Coronary Syndrome (PL-ACS) (n = 581 843) and SILICARD (n = 852 063) databases. Atrial fibrillation at admission was diagnosed in of 6.16% patients [de novo: 1129 (2.46%); pre-existing: 1691 (3.7%)]. Groups were compared (N = 1023 vs. 1023) after matching for relevant clinical factors. De novo and pre-existing AF differed in in-hospital diuretic (52% vs. 58%; P = 0.008) and aldosterone inhibitor (27.5% vs. 32.5%; P = 0.02) use, Thrombolysis In Myocardial Infarction (TIMI) flow before percutaneous coronary intervention (P = 0.016), and diuretic (52.1% vs. 58%; P = 0.008) and oral anticoagulant (27.5% vs. 32.5%; P = 0.018) use at discharge. In-hospital mortality in the de novo AF group was significantly higher (13.1% vs. 8.31%; P = 0.0005). Post-discharge 12-month survival was similar between groups (14.5% vs. 15.3%, P = 0.63). Long-term re-hospitalization due to heart failure (22.7% vs. 17.2%; P < 0.005) and medical contact due to AF (48.4% vs. 26.1%, P < 0.0001) rates were higher in the group with pre-existing AF, without the difference of stroke or myocardial infarction occurrence. CONCLUSION: De novo AF accounts for 40% of all AF cases in ACS patients and is an unfavourable in-hospital prognostic factor. The occurrence of de novo AF during ACS should require special attention and caution in the treatment of these patients.

Thrombus aspiration followed by direct stenting: a novel strategy of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction. Results of the Polish-Italian-Hungarian RAndomized ThrombEctomy Trial (PIHRATE Trial).

BACKGROUND: Previous studies with thrombectomy showed different results, mainly due to use of thrombectomy as an additional device not instead of balloon predilatation. The aim of the present study was to assess impact of aspiration thrombectomy followed by direct stenting. METHODS: Patients with ST elevation myocardial infarction (STEMI) <6 hours from pain onset and occluded infarct-related artery in baseline angiography were randomized into aspiration thrombectomy followed by direct stenting (TS, n = 100) or standard balloon predilatation followed by stent implantation (n = 96). The primary end point of the study was the electrocardiographic ST-segment elevation resolution >70% (STR > 70%) 60 minutes after primary angioplasty (percutaneous coronary intervention [PCI]). Secondary end points included angiographic myocardial blush grade (MBG) after PCI, combination of STR > 70% immediately after PCI and MBG grade 3 (optimal myocardial reperfusion), Thrombolysis In Myocardial Infarction flow after PCI, angiographic complications, and in-hospital major adverse cardiac events. RESULTS: Aspiration thrombectomy success rate was 91% (crossing of the lesion with thrombus reduction and flow restoration). There was no significant difference in STR ≥ 70% after 60 minutes (53.7% vs 35.1%, P = .29). STR > 70% immediately after PCI (41% vs 26%, P < .05), MBG grade 3 (76% vs 58%, P < .03), and optimal myocardial reperfusion (35.1% vs 11.8%, P < .001) were more frequent in TS. There was no difference in between the groups in 6-month mortality (4% vs 3.1%, P = .74) and reinfarction rate (1% vs 3.1%, P = .29). CONCLUSIONS: Aspiration thrombectomy and direct stenting is safe and effective in STEMI patients with early presentation (<6 hours). The angiographic parameters of microcirculation reperfusion and ECG ST-segment resolution directly after PCI were significantly better in thrombectomy group despite the lack of the difference in ST-segment resolution 60 minutes after PCI.

Relationship between low-density lipoprotein cholesterol level on admission and in-hospital mortality in patients with ST-segment elevation myocardial infarction, with or without diabetes, treated with percutaneous coronary intervention.

BACKGROUND: Low-density lipoprotein cholesterol (LDL-C) is the independent risk factor for coronary artery disease. Diabetes mellitus (DM) is associated with poor outcome in patients with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary interventions (PCI). The relationship between LDL-C and mortality in patients with STEMI has not been well established. AIM: To assess whether the LDL-C level on admission can predict in-hospital mortality in patients with or without DM treated with PCI for STEMI. METHODS: 1808 consecutive patients with STEMI (378 with DM) treated with PCI were included in the analysis. Patients were divided according to the presence of DM and LDL-C level on admission with a threshold of 3.7 mmol/L (143 mg/dL). In the diabetic group there were 208 patients with LDL-C〈 3.7 mmol/L (143 mg/dL) and 170 with LDL-C ≥ 3.7 mmol/L (143 mg/dL), whereas in the non-diabetic group 726 and 704 patients, respectively. We analysed the effects of LDL-C level and various risk factors on in-hospital mortality separately for patients with or without DM. RESULTS: The mean total cholesterol (5.6 ± 1.4 vs 5.7 ± 1.5 mmol/L; 216.6 ± 54.1 vs 220.4 ± 58 mg/dL, p = 0.21), LDL-C (3.6 ± 1.3 vs 3.7 ± 1.5 mmol/L; 139.2 ± 50.3 vs 143.0 ± 58 mg/dL, p = 0.11) and triglyceride level (1.7 ± 0.6 vs 1.6 ± 0.5 mmol/L; 150 ± 52.9 vs 141.2 ± 44.1 mg/dL, p = 0.30) were similar in patients with or without DM, whereas HDL-C level was lower in diabetic patients (1.4 ± 0.6 vs 1.8 ± 0.5 mmol/L; 53.7 ± 23.0 vs 69 ± 19.2 mg/dL, p = 0.049). The in-hospital mortality was 6.1% and 3.2%, for patients with or without DM, respectively (p = 0.008). In the diabetic group in-hospital mortality was higher in patients with LDL-C level on admission ≥ 3.7 mmol/L (143 mg/dL) in comparison to the patients with LDL-C〈 3.7 mmol/L (143 mg/dL; 7.1% vs 4.8%; p = 0.03). The multivariate analysis revealed that in diabetics an increase in LDL-C level on admission by 1 mmol/L (38.67 mg/dL) was related to a 45% increase in in-hospital mortality (OR 1.45, 95% CI 1.10-2.00, p = 0.023). In the non-diabetic group in-hospital mortality was similar in patients with LDL-C level on admission ≥ 3.7 mmol/L (143 mg/dL) and〈 3.7 mmol/L (143 mg/dL); 2.6% vs 3.7%; p = 0.21. In multivariate analysis LDL-C level was not related with in-hospital mortality in patients without DM (per 1 mmol/L; 38.67 mg/dL); OR 0.95, 95% CI 0.70-1.27, p = 0.71. CONCLUSIONS: Elevated LDL-C level on admission is associated with increased in-hospital mortality in diabetic but not in non-diabetic patients treated with PCI for STEMI.

New hope for patients and challenges for the multidisciplinary arrhythmia team: a hybrid convergent approach for atrial fibrillation treatment.

BACKGROUND: Available data suggest the important role of ablation of the left atrial posterior wall and epicardial myocardial layers in rhythm control therapy in patients with persistent drug­refractory atrial fibrillation (AF). However, endocardial ablation is not always effective in transmural substrate modification. The alternative treatment option is minimally invasive hybrid approach (HABL) combining the strengths of surgical and catheter ablation. AIM: This study aimed to assess the periprocedural safety as well as acute and long­term outcomes of HABL for AF. METHODS: This is a retrospective single­center study of patients who underwent HABL using the minimally invasive transabdominal approach between July 2009 and January 2020. Demographic in­hospital data and 12­month follow­up results were obtained. The number of hospitalizations, cardioversions, re­ablations, and severe adverse events in a 3­year period before and after HABL were compared using data from the national healthcare provider. RESULTS: In total, 158 patients (mean [SD] age, 51.02 [10.67] years) who underwent HABL were included; 61.4% had persistent AF. There was a 4.4% incidence of periprocedural complications without any fatalities. In 66% of patients, additional endocardial substrate modification was needed, in 52.6% on the posterior wall. In the 12­month follow­up, most patients (78.3%) remained free of arrhythmias. There was a significant reduction in the number of hospitalizations (for AF, 1.65 vs 0.54; or any other cause, 2.56 vs 1.31 per patient), cardioversions, and re­ablations after HABL (all P <0.05). CONCLUSIONS: The hybrid multidisciplinary approach for treatment of AF is a safe and very effective treatment method in long­term follow­up, which reduces healthcare burden. It could be considered as an alternative therapeutic option especially in patients with persistent AF.

Temporal trends in the availability and efficacy of catheter ablation for atrial fibrillation and atrial flutter in a highly populated urban area.

BACKGROUND: Pulmonary vein isolation has become one of the core modalities of the rhythm control strategy in patients with atrial fibrillation (AF). AIMS: The aim of the study was to analyze temporal trends in the availability and efficacy of AF and atrial flutter (AFL) catheter ablation in an urban area of Upper Silesia in Poland. METHODS: The source data were obtained from the SILCARD (Silesian Cardiovascular Database) covering an adult population of 3.8 million. The final study population included patients with diagnosis code I48 referred for catheter ablation between 2006 and 2017. The data included total number of procedures, patient sex, age, comorbidities, number of hospital admissions, and mortality rate. RESULTS: A total of 2745 patients were enrolled. The number of ablated patients increased more than 10­fold (43 in 2006 vs 507 in 2017; P = 0.008) in the follow­up period. The analysis showed an upward trend in the proportion of women (P = 0.02), hypertension prevalence (P = 0.004), and percentage of patients implanted (P = 0.02). A decrease was observed in the percentage of patients with stable angina (P <0.005) and hospitalization length (P <0.005). The all­cause hospital readmissions rate decreased from 55.8% to 25.4% (P <0.005). There were significant reductions in the 12­month all­cause mortality (2.3% in 2006 vs 0.2% in 2017; P <0.005), stroke (2.3% in 2006 vs 0.2% in 2017; P = 0.047), and myocardial infarction rates (2.3% in 2006 vs 0.4% in 2017; P = 0.03). CONCLUSIONS: A considerable increase in the availability and efficacy of AF / AFL ablations was documented over the 12­year follow­up period.

The influence of ablation power reduction associated with oesophagus location on pulmonary vein isolation results in patients with paroxysmal atrial fibrillation: six-month follow-up.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) could be associated with a thermal oesophageal (EO) injury. To avoid this complication intraluminal EO temperature monitoring and ablation power reduction at the areas with excessive heating could be used. However, the reduced energy could limit the ablation lesion depth, without creation of lasting transmural scar and influence on long-term ablation results. AIM: The primary goal was to evaluate the homogeneity of forced ablation power reduction due to excessive EO heating in different parts of the left atrium. The secondary goal was to assess the influence of power reduction in different EO locations on long-term AF recurrence. METHODS: We examined retrospectively 109 consecutive patients with symptomatic, medically refractory paroxysmal AF, who underwent pulmonary vein isolation using radiofrequency ablation. In 40.4% of the patients the EO course was central (group B) left atrium posterior wall, in 31.2% it was left sided (group A), and in 28.4% it was right sided (group C). RESULTS: The maximal measured temperature (41.0 ± 1.0 vs. 39.2 ± 1.5 vs. 40.6 ± 0.7°C) and forced ablation power (15.9 ± 5.6 vs. 23.5 ± 6.1 vs. 17.4 ± 5.7 W) differed significantly according to the EO course (A, B, C, respectively). In six-month follow-up 76.15% of patients were free of arrhythmias. There was no statistically significant difference between groups (A-C) regarding the AF recurrence rate: 32.4% vs. 20.5% vs. 19.4% (p = 0.37). CONCLUSIONS: The maximal intraluminal EO temperatures and the necessary level of power reduction during AF ablation are inhomogeneous in different parts of the left atrium, but they are not associated with different six-month follow-up results.

The impact of remote monitoring of implanted cardioverter-defibrillator (ICD) and cardiac resynchronisation therapy device (CRT-D) patients on healthcare costs in the Silesian population: three-year follow-up.

BACKGROUND: The population of patients with implanted cardioverter-defibrillators (ICD) and cardiac resynchronisation therapy devices (CRT-D) is constantly growing. The use of remote-monitoring (RM) techniques in this group can significantly improve clinical outcomes, but there are limited data about the impact of RM on healthcare costs from a payer's perspective. AIM: The aim of the study was to assess the impact on costs for the healthcare system of RM in patients with ICD or CRT-D. METHODS: We examined a cohort of 842 patients with ICD or CRT-D. The group was divided into two groups based on RM (or no RM [NRM]), matched according to important clinical characteristics. The subjects were followed for a maximum of three years after implantation (mean follow-up 2.11 ± 0.83 years). The overall costs for the healthcare provider in the follow-up were defined as the primary endpoint. The secondary endpoint was the use of different types of medical contact events: hospitalisation and number of in-clinic and general practitioner visits (without the number of remote transmissions). RESULTS: In the three-year follow-up, the reduction in the costs of treatment for National Health Care in the RM group was 33.5% (median value, p < 0.001). In patients with implanted CRT-D, the reduction reached 42.7% (p = 0.011), and with ICD it was 31.3% (p = 0.007). We observed no significant reduction in the median hospitalisation costs in the three-year follow-up in the RM group (p = NS), despite a 25% drop in the mean value. The costs of outpatient visits were slightly higher in the RM group (p = NS). In the follow-up period, there was no reduction in the number of medical contact events (p = NS). CONCLUSIONS: Remote monitoring in patients with implanted ICD or CRT-D devices reduces the cost for the national healthcare provider.

Staged hybrid ablation for persistent and longstanding persistent atrial fibrillation effectively restores sinus rhythm in long-term observation.

INTRODUCTION: Hybrid ablation (HABL) of atrial fibrillation combining endoscopic, minimally invasive, closed chest epicardial ablation with endocardial CARTO-guided accuracy was introduced to overcome the limitations of current therapeutic options for patients with persistent (PSAF) and longstanding persistent atrial fibrillation (LSPAF). The purpose of this study was to evaluate the procedural safety and feasibility as well as effectiveness of HABL in patients with PSAF and LSPAF 1 year after the procedure. MATERIAL AND METHODS: The study is a single-center, prospective clinical registry. From 07/2009 to 12.2014, 90 patients with PSAF (n = 39) and LSPAF (n = 51), at the mean age of 54.8 ±9.8, in mean EHRA class 2.6, underwent HABL. 64.4% of patients had a history of prior cardioversion or catheter ablation. Thirteen patients had LVEF less than 35%. Mean AF duration was 4.5 ±3.7 years. Patients were scheduled for 3-, 6- and 12-month follow-up with 7-day Holter monitoring. RESULTS: At 6 months after the procedure 78% (54/69) of patients were in SR. At 12 months after the procedure 86% (59/69) were in SR and 62.3% (43/69) in SR and off class I/III antiarrhythmic drugs (AADs). Only 1% (1/69) of patients required a repeat ablation for atrial flutter. A significant decrease in LA dimension and an increase in LVEF were noted. CONCLUSIONS: A combination of epicardial and endocardial RF ablation should be considered as a treatment option for patients with persistent and long-standing persistent atrial fibrillation as it is safe and effective in restoring sinus rhythm.

Periprocedural checklist in the catheterisation laboratory is associated with decreased rate of treatment complications.

BACKGROUND: Interventional cardiology and electrophysiology are disciplines with a growing number of complex procedures, which are exposed to the occurrence of many complications. AIM: To assess efficacy and legitimacy of the periprocedural checklist in prevention of cardiovascular adverse events, in elective patients undergoing invasive diagnostic and treatment. METHODS: A total of 2064 patients directed to treatment in the catheterisation laboratory between May 2011 to August 2012 were analysed. Patients who were hospitalised without invasive diagnostics and treatment were not included in the study. Patients were divided into two groups: a control group - 1011 patients with invasive diagnostics and treatment before introduction of periprocedural checklist; and an intervention group - 1053 patients with invasive diagnostics and treatment after introduction of periprocedural checklist. We analysed the studied groups, assessing adverse events associated with hospitalisation and performed procedures. We also conducted subjective evaluation of checklists by medical staff on the basis of a questionnaire. RESULTS: Baseline characteristics between the studied groups were comparable except for a higher rate of stable coronary artery disease (50.7% vs. 39.6%, p £ 0.001) and electrophysiology procedures in the control group. Implementation of a checklist was favourable in cases of decreased adverse events (6.8% vs. 3.9%, p = 0.004) especially bleedings (2.3% vs. 0.3%, p < 0.001). Multivariate analysis confirmed that lack of a periprocedural checklist during hospitalisation was an independent factor associated with a higher rate of adverse events (OR = 2.97, 95% CI 1.60-5.53, p = 0.001). Subjective evaluation of medical staff opinions showed that implementation of a checklist seems to be associated with improved communication skills, work organisation, prevention of the occurrence of medical errors, and reduced rate of complications associated with procedures. CONCLUSIONS: Introduction of a periprocedural checklist was associated with significant reduction of adverse events among patients undergoing invasive procedures. It also showed a positive influence on team communication, and organisation and quality of treatment, according to the opinions of medical staff.

Prospective, multicenter validation of a clinical risk score for left atrial arrhythmogenic substrate based on voltage analysis: DR-FLASH score.

BACKGROUND: Left atrial (LA) low-voltage areas (LVAs) are frequently observed in patients with atrial fibrillation (AF) and may predict AF recurrence after catheter ablation. OBJECTIVE: The aim of this study was to develop and validate a clinical tool to identify LVAs that are associated with AF recurrence after pulmonary vein isolation (PVI). METHODS: In a cohort of 238 patients, voltage maps were created during LA procedures. LVAs were defined as areas with electrogram amplitudes <0.5 mV. On the basis of regression analysis, predictors of LA substrate were identified. These parameters were used to establish a dedicated risk score (DR-FLASH score, based on diabetes mellitus, renal dysfunction, persistent form of AF, LA diameter >45 mm, age >65 years, female sex, and hypertension). This risk score was then prospectively validated in a multicenter cohort of 180 patients. The association of the score with long-term recurrence of atrial arrhythmias after circumferential PVI was tested in a retrospective cohort of 484 patients. RESULTS: The DR-FLASH score effectively identified LVA substrate (C statistic = 0.801, P < .001). In the prospective multicenter validation cohort, the predictive value of the DR-FLASH score was confirmed (C statistic = 0.767, P < .001). The probability for the presence of LA substrate increased by a factor of 2.2 (95% confidence interval [CI] 1.6-2.9, P < .001) with each point scored. Furthermore, the risk of AF recurrence after PVI increased by a factor of 1.3 (95% CI 1.1-1.5, P < .001) with every additional point and was almost 2 times higher in patients with a DR-FLASH score >3 (odds ratio 1.7, 95% CI 1.1-2.8, P = .026). CONCLUSION: The DR-FLASH score may be useful to identify patients who may require extensive substrate modification instead of PVI alone.