Subjective identification and ablation of drivers improves rhythm control in patients with persistent atrial fibrillation. The CHAOS-AF study.

INTRODUCTION AND OBJECTIVES: The optimal approach for persistent atrial fibrillation (AF) ablation remains unknown. In patients with persistent AF, we compared an ablation strategy based on pulmonary vein isolation (PVI) plus ablation of drivers (PVI+D), with a conventional PVI-only approach performed in a 1:1 propensity score-matched cohort. METHODS: Drivers were subjectively identified using conventional high-density mapping catheters (IntellaMap ORION, PentaRay NAV or Advisor HD Grid), without dedicated software, as fractionated continuous or quasicontinuous electrograms on 1 to 2 adjacent bipoles, which were ablated first; and as sites with spatiotemporal dispersion (the entire cycle length comprised within the mapping catheter) plus noncontinuous fractionation, which were only targeted in patients without fractionated continuous electrograms, or without AF conversion after ablation of fractionated continuous electrograms. Ablation included PVI plus focal or linear ablation targeting drivers. RESULTS: A total of 50 patients were included in each group (61±10 years, 25% women). Fractionated continuous electrograms were found and ablated in 21 patients from the PVI+D group (42%), leading to AF conversion in 7 patients. In the remaining 43 patients, 143 sites with spatiotemporal dispersion plus noncontinuous fractionation were targeted. Globally, AF conversion was achieved in 21 patients (42%). The PVI+D group showed lower atrial arrhythmia recurrences at 1 year of follow-up (30.6% vs 48%; P=.048) and at the last follow-up (46% vs 72%; P=.013), and less progression to permanent AF (10% vs 40%; P=.001). CONCLUSIONS: Subjective identification and ablation of drivers, added to PVI, increased 1-year freedom from atrial arrhythmia and decreased long-term recurrences and progression to permanent AF.

New technologies for the diagnosis, treatment, and monitoring of cardiovascular diseases.

Telemedicine enables the remote provision of medical care through information and communication technologies, facilitating data transmission, patient participation, promotion of heart-healthy habits, diagnosis, early detection of acute decompensation, and monitoring and follow-up of cardiovascular diseases. Wearable devices have multiple clinical applications, ranging from arrhythmia detection to remote monitoring of chronic diseases and risk factors. Integrating these technologies safely and effectively into routine clinical practice will require a multidisciplinary approach. Technological advances and data management will increase telemonitoring strategies, which will allow greater accessibility and equity, as well as more efficient and accurate patient care. However, there are still unresolved issues, such as identifying the most appropriate technological infrastructure, integrating these data into medical records, and addressing the digital divide, which can hamper patients' adoption of remote care. This article provides an updated overview of digital tools for a more comprehensive approach to atrial fibrillation, heart failure, risk factors, and treatment adherence.

Symptom burden guiding invasive electrophysiological study in paroxysmal supraventricular tachycardia: The believe SVT registry.

BACKGROUND AND OBJECTIVE: Patients with palpitations clinically suggestive of paroxysmal supraventricular tachycardia (PSVT) are often managed conservatively until ECG-documentation of the tachycardia, leading to high impact on life quality and healthcare resource utilization. We evaluated results of electrophysiological study (EPS), and ablation when appropriate, among these patients, with special focus on gender differences in management. METHODS: BELIEVE SVT is a European multicenter, retrospective registry in tertiary hospitals performing EPS in patients with palpitations, without ECG-documentation of tachycardia or preexcitation, and considered highly suggestive of PSVT by a cardiologist or cardiac electrophysiologist. We analyzed clinical characteristics, results of EPS and ablation, complications, and clinical outcomes during follow-up. RESULTS: Six-hundred eighty patients from 20 centers were included. EPS showed sustained tachycardia in 60.9% of patients, and substrate potentially enabling AVNRT in 14.7%. No major/permanent complications occurred. Minor/transient complications were reported in 0.84% of patients undergoing diagnostic-only EPS and 1.8% when followed by ablation. During a 3.4-year follow-up, 76.2% of patients remained free of palpitations recurrence. Ablation (OR: 0.34, P < .01) and male gender (OR: 0.58, P = .01) predicted no recurrence. Despite a higher female proportion among patients with recurrence, (77.2% vs 63.5% among those asymptomatic during follow-up, P < .01), 73% of women in this study reported no recurrence of palpitations after EPS. CONCLUSIONS: EPS and ablation are safe and effective in preventing recurrence of nondocumented palpitations clinically suggestive of PSVT. Despite a lower efficacy, this strategy is also highly effective among women and warrants no gender differences in management.

Case Series of Ventricular Tachycardia Ablation With Pulsed-Field Ablation: Pushing Technology Further (Into the Ventricle).

Three cases of ventricular tachycardia ablation with pulsed-field ablation technology performed at 2 separate centers are reported, highlighting the advantages and disadvantages of this tool inside the ventricle: its dependence on proximity rather than contact makes it useful in sites with poor stability, while the speed of application and large scope of action provided by commercially available catheters could help with ablating large diseased areas of endocardium in a fast and hemodynamically well-tolerated fashion. However, lesion depth could be insufficient for guaranteeing efficacy in preventing ventricular tachycardias originating at an epicardial site, even in the right ventricle.

Automatic identification of areas with low-voltage fragmented electrograms for the detection of the critical isthmus of atypical atrial flutters.

INTRODUCTION: Critical isthmuses of atypical atrial flutters (AAFLs) are usually located at slow conduction areas that exhibit fractionated electrograms. We tested a novel software, intended for integration with a commercially available navigation system, that automatically detects fractionated electrograms, to identify the critical isthmus in patients with AAFL ablation. METHODS AND RESULTS: All available patients were analyzed; 27 patients with 33 AAFLs were included. The PentaRay NAV catheter (Biosense Webster) was used for mapping. The novel software was retrospectively applied; fractionated points with duration ≥80 ms and bipolar voltage between 0.05 and 0.5 mV were highlighted on the surface of maps. In 10 randomly chosen AAFLs, an expert electrophysiologist evaluated the positive predictive value of the algorithm to detect true fractionation: 74.4%. We tested the capacity of the software to identify areas of fractionation (defined as clusters of ≥3 adjacent points with fractionation) at the critical isthmus of the AAFLs (defined using conventional mapping criteria). An area of fractionation was identified at the critical isthmus in 30 cases (91%). Globally, 144 areas of fractionation (median number per AAFL 4 [3-6]) were identified. Duration of the fractionation or the surface of the areas was not different between areas at critical isthmuses and the rest. Setting the fractionation score filter of the software in nine provided best performance. CONCLUSIONS: The novel software detected areas of fractionation at the critical isthmus in most AAFLs, which may help identify the critical isthmus in clinical practice.

Smartwatch ECG Tracing and Ischemic Heart Disease: ACS Watch Study.

BACKGROUND: Smartwatches have become a widely used tool for health self-care. Its role in ischemic heart disease (IHD) has not been assessed. Objetcive: The aim of this study was to evaluate the usefulness of smartwatch ECG registry in IHD. METHODS: We present an observational study of 25 consecutive patients with acute IHD. Conventional ECG and smartwatch tracing were obtained simultaneously at admission. Waves of conventional and smartwatch ECGs were objectively compared. A survey on medical attitude was conducted among 12 physicians (3 cardiologists, 3 intensivists, 3 emergency physicians, and 3 general practitioners) and a score (1-5) of concordance between the records was requested. RESULTS: There were no differences in Q-wave, R-wave, ST segment, or T-wave. There was a very strong correlation between ST segments, a strong correlation in Q-waves and R-waves, and a moderate correlation in T-wave measurements. All specialists obtained a high level of agreement (4.45 ± 0.45). Smartwatch tracings would lead to similar management compared to conventional ECG. There were only 6 (2%) discrepant cases due to differences in inferior repolarization, showing an almost perfect agreement (kappa = 0.96). CONCLUSIONS: In most patients with acute IHD, smartwatch ECG tracing is a reliable tool to make the diagnosis and guide appropriate medical care. However, due to their intrinsic limitations, inferior myocardial infarctions may be missed and require a conventional 12-lead ECG to rule them out.

Stabilization of unstable reentrant atrial tachycardias via fractionated continuous electrical activity ablation (CHAOS study).

BACKGROUND: Unstable reentrant atrial tachycardias (ATs) (i.e., those with frequent circuit modification or conversion to atrial fibrillation) are challenging to ablate. We tested a strategy to achieve arrhythmia stabilization into mappable stable ATs based on the detection and ablation of rotors. METHODS: All consecutive patients from May 2017 to December 2019 were included. Mapping was performed using conventional high-density mapping catheters (IntellaMap ORION, PentaRay NAV, or Advisor HD Grid). Rotors were subjectively identified as fractionated continuous (or quasi-continuous) electrograms on 1-2 adjacent bipoles, without dedicated software. In patients without detectable rotors, sites with spatiotemporal dispersion (i.e., all the cycle length comprised within the mapping catheter) plus non-continuous fractionation on single bipoles were targeted. Ablation success was defined as conversion to a stable AT or sinus rhythm. RESULTS: Ninety-seven patients with reentrant ATs were ablated. Of these, 18 (18.6%) presented unstable circuits. Thirteen (72%) patients had detectable rotors (median 2 [1-3] rotors per patient); focal ablation was successful in 12 (92%). In the other 5 patients, 17 sites with spatiotemporal dispersion were identified and targeted. Globally, and excluding 1 patient with spontaneous AT stabilization, ablation success was achieved in 16/17 patients (94.1%). One-year freedom from atrial arrhythmias was similar between patients with unstable and stable ATs (66.7% vs. 65.8%, p = 0.946). CONCLUSIONS: Most unstable reentrant ATs show detectable rotors, identified as sites with single-bipole fractionated quasi-continuous signals, or spatiotemporal dispersion plus non-continuous fractionation. Ablation of these sites is highly effective to stabilize the AT or convert it into sinus rhythm.

Characterization of high-power and very-high-power short-duration radiofrequency lesions performed with a new-generation catheter and a temperature-control ablation mode.

INTRODUCTION: High-power short-duration (HPSD) has been proposed to shorten procedure times while maintaining efficacy and safety. We evaluated the differences in size and geometry between radiofrequency lesions obtained with this method and conventional ones. METHODS AND RESULTS: Twenty-eight sets of 10 perpendicular radiofrequency applications were performed with two commercially available catheters: a temperature-controlled HPSD catheter (QDot-Micro) and a conventional power-controlled catheter (Thermocool SmartTouch) on porcine left ventricle. Different power settings (35, 40, 50, and 90 W), contact force (CF; 10 and 20 g), ablation index (AI; 400 and 550), and application times were combined to create conventional (35-40 W), HPSD (50 W) and very-high-power short-duration (VHPSD; 90 W) lesions, that were cross-sectioned and measured. About 4-s VHPSD lesions were smaller, shallower, and thinner than HPSD performed with the QDot-Micro catheter in any scenario of CF or AI (61 ± 7.8 mm3 , 6.1 ± 0.3 mm wide, and 2.9 ± 0.1 mm deep with 10 g; 72.2 ± 0.5 mm3 , 6.8 ± 0.3 mm wide, and 2.9 ± 0.2 mm deep with 20 g). Conventional and HPSD lesions performed with the temperature-controlled catheter were generally bigger, deeper, and wider than the ones obtained with the power-controlled catheter, as well as more consistent in size. This was especially true with the lower CF and AI scenario, while differences were less notable with other setting combinations. CONCLUSION: VHPSD lesions performed with QDot-Micro catheter were smaller than any other lesions, which is especially attractive for posterior left atrial wall ablation. On the contrary, conventional-powered and HPSD lesions performed with this catheter were equally sized (or even bigger with lower CF and AI objectives), as well as more consistent in size, which would guarantee transmurality in other locations.

Impact of power and contact force on index-guided radiofrequency lesions in an ex vivo porcine heart model.

PURPOSE: Lesion size index (LSI) and ablation index (AI) are markers of lesion quality that incorporate power, contact force (CF) and time in a weighted formula to estimate lesion size. Although accurate predicting lesion depth in vitro, their precision in lesion size estimation has not been well established for certain power and CF settings. We conducted an experimental ex vivo study to analyse the effect of power and CF in size and morphology of ablation lesions in a porcine heart model. METHODS: Twenty-four sets of 10 perpendicular epicardial radiofrequency applications were performed with two commercially available catheters (TactiCath, Sensor Enabled; and SmartTouch) on porcine left ventricle submerged in 37 °C saline, combining different power (25, 30, 35, 40, 50 and 60 W) and CF (10 and 20 g) settings, and aiming at a lower (LSI/AI of 5/400) or higher (LSI/AI of 6/550) index. After each application, lesions were cross-sectioned and measured. RESULTS: Four hundred eighty lesions were performed. For a given target index and CF, significant differences in lesion volume and depth with different power were observed with both catheters, generally with smaller lesions using higher power. Lesions performed with CF of 10 g were particularly smaller with TactiCath compared to SmartTouch; lesions with CF of 20 g aiming a low LSI/AI were, however, bigger; lesions with CF of 20 g aiming a high LSI/AI were similar. In general, high-power lesions were wider and shallower than low-power lesions, especially with SmartTouch. CONCLUSION: Size and morphology of index-guided radiofrequency lesions varied significantly with different power and CF settings.

High-density mapping with fragmentation analysis in patients with reentrant atrial tachycardias (MAP-FLURHY study).

PURPOSE: Reentrant atrial tachycardias (ATs) use areas of slow conduction that can be visualized as fragmented electrograms. We aimed to test an ablation strategy based on the identification and ablation of spots with fragmented electrograms in reentrant ATs, using Rhythmia navigation system. METHODS: All consecutive patients from June 2016 to June 2019 were included. The IntellaMap ORION Catheter was used to detect sites with fragmentation, arbitrarily defined as fragmented electrograms > 70 ms. Entrainment was used to check if these areas belonged to the AT circuit. Ablation targeted the longest fragmented electrogram within the circuit: focal ablation for microreentries and lines for macroreentries. Ablation success was defined from each AT as conversion to sinus rhythm or another AT. RESULTS: Twenty-seven consecutive patients with 44 mappable ATs were included. All ATs showed sites with fragmented electrograms (104 sites; 2.4 sites per AT); 43/44 ATs had fragmented electrograms within the circuit, which were the target of ablation. Ablation success: 34/36 ATs (94%); success could not be assessed in 8 circuits, in 6 due to mechanical conversion to sinus rhythm at the target fragmented site. Fragmented electrograms within the AT circuits were longer than electrograms outside the circuits (110 ± 30 vs 90 ± 15 ms, p < 0.001). A fragmentation duration > 100 ms/ > 40% of the AT cycle length predicted to be a successful site for ablation with 72.3%/73.8% specificity, respectively. Sixty-two percent of the patients were free from atrial arrhythmias at 1 year. CONCLUSIONS: Most ATs had detectable fragmented electrograms within the circuit, which could be the target of ablation with high efficacy.

Frailty predicts major bleeding within 30days in elderly patients with Acute Coronary Syndrome.

OBJECTIVE: Bleeding in ACS patients is an independent marker of adverse outcomes. Its prognostic impact is even worse in elderly population. Current bleeding risk scores include chronological age but do not consider biologic vulnerability. No studies have assessed the effect of frailty on major bleeding. The aim of this study is to determine whether frailty status increases bleeding risk in patients with ACS. METHODS: This prospective and observational study included patients aged ≥75years admitted due to type 1 myocardial infarction. Exclusion criteria were severe cognitive impairment, impossibility to measure handgrip strength, cardiogenic shock and limited life expectancy due to oncologic diseases. The primary endpoint was 30-day major bleeding defined as a decrease of ≥3g/dl of haemoglobin or need of transfusion. RESULTS: A total of 190 patients were included. Frail patients (72, 37.9%) were older, with higher comorbidity features and with a higher CRUSADE score at admission. On univariate analysis, frailty predicted major bleeding during 30-day follow-up despite less frequent use of a P2Y12 inhibitor (66.2% vs 83.6%, p=0.007) and decreased catheterisation rate (69.4% vs 94.1%, p<0.001). Major bleeding was associated with increased all-cause mortality at day 30 (18.2% vs 2.5%, p<0.001). On multivariate analysis, frailty was an independent predictor for major bleeding. CONCLUSION: Frailty phenotype, as a marker of biological vulnerability, is an independent predictor of major bleeding in elderly patients with ACS. Frailty can play an important role in bleeding risk stratification and objective indices should be integrated into routine initial evaluation of these patients.