Classification of Left Atrial Diseased Tissue Burden Determined by Automated Voltage Analysis Predicts Outcomes after Ablation for Atrial Fibrillation.

BACKGROUND: The burden and persistence of atrial fibrillation (AF) have been associated with the presence and extent of left atrial (LA) fibrosis. Recent reports have implicated an association between the extent of LA fibrosis and the outcome of pulmonary vein isolation (PVI). We aimed to analyse the value of an automated scar quantification method in the prediction of success following PVI. METHODS: One hundred and nine consecutive patients undergoing PVI for paroxysmal or persistent AF were included in our observational study with a 2-year follow-up. Prior to PVI, patients underwent high-definition LA electroanatomical mapping, and scar burden was quantified by automated software (Voltage Histogram Analysis, CARTO 3, Biosense Webster), then classified into 4 subgroups (Dublin Classes I-IV). Recurrence rates were analysed on and off antiarrhythmic drug therapy (AAD), respectively. RESULTS: The overall success rate was 74% and 67% off AAD at 1- and 2-year follow-up, respectively. Patients with Dublin Class IV had significantly lower success rates (p = 0.008, off AAD). Dublin Class IV (OR = 2.27, p = 0.022, off AAD) and the presence of arrhythmia in the blanking period (OR = 3.28, p = 0.001, off AAD) were the only significant predictors of recurrence. The use of AAD did not affect these results. CONCLUSIONS: We propose a classification of low voltage areas based on automated quantification by software during 3D mapping prior to PVI. Patients with high burden of low voltage areas (>31% of <0.5 mV, Dublin Class IV) have a higher risk of recurrence following PVI. Information gathered during electroanatomical mapping may have important prognostic value.

The European TeleCheck-AF project on remote app-based management of atrial fibrillation during the COVID-19 pandemic: centre and patient experiences.

AIMS: TeleCheck-AF is a multicentre international project initiated to maintain care delivery for patients with atrial fibrillation (AF) during COVID-19 through teleconsultations supported by an on-demand photoplethysmography-based heart rate and rhythm monitoring app (FibriCheck®). We describe the characteristics, inclusion rates, and experiences from participating centres according the TeleCheck-AF infrastructure as well as characteristics and experiences from recruited patients. METHODS AND RESULTS: Three surveys exploring centre characteristics (n = 25), centre experiences (n = 23), and patient experiences (n = 826) were completed. Self-reported patient characteristics were obtained from the app. Most centres were academic (64%) and specialized public cardiology/district hospitals (36%). Majority of the centres had AF outpatient clinics (64%) and only 36% had AF ablation clinics. The time required to start patient inclusion and total number of included patients in the project was comparable for centres experienced (56%) or inexperienced in mHealth use. Within 28 weeks, 1930 AF patients were recruited, mainly for remote AF control (31% of patients) and AF ablation follow-up (42%). Average inclusion rate was highest during the lockdown restrictions and reached a steady state at a lower level after easing the restrictions (188 vs. 52 weekly recruited patients). Majority (>80%) of the centres reported no problems during the implementation of the TeleCheck-AF approach. Recruited patients [median age 64 (55-71), 62% male] agreed that the FibriCheck® app was easy to use (94%). CONCLUSION: Despite different health care settings and mobile health experiences, the TeleCheck-AF approach could be set up within an extremely short time and easily used in different European centres during COVID-19.

The Value of Voltage Histogram Analysis Derived Right Atrial Scar Burden in the Prediction of Left Atrial Scar Burden.

INTRODUCTION: Growing evidence suggests that fibrotic changes can be observed in atrial fibrillation (AF) in both atria. Quantification of the scar burden during electroanatomical mapping might have important therapeutic and prognostic consequences. However, as the current invasive treatment of AF is focused on the left atrium (LA), the role of the right atrium (RA) is less well understood. We aimed to characterize the clinical determinates of the RA low-voltage burden and its relation to the LA scaring. METHODS: We have included 36 patients who underwent catheter ablation for AF in a prospective observational study. In addition to LA mapping and ablation, high-density RA bipolar voltage maps (HD-EAM) were also reconstructed. The extent of the diseased RA tissue (≤0.5 mV) was quantified using the voltage histogram analysis tool (CARTO®3, Biosense Webster). RESULTS: The percentage of RA diseased tissue burden was significantly higher in patients with a CHA2DS2-VASc score ≥ 2 (p = 0.0305), higher indexed LA volume on the CTA scan and on the HD-EAM (p = 0.0223 and p = 0.0064, respectively), or higher indexed RA volume on the HD-EAM (p = 0.0026). High RA diseased tissue burden predicted the presence of high LA diseased tissue burden (OR = 7.1, CI (95%): 1.3-38.9, p = 0.0145), and there was a significant correlation of the same (r = 0.6461, p < 0.0001). CONCLUSIONS: Determining the extent of the right atrial low-voltage burden might give useful clinical information. According to our results, the diseased tissue burden correlates well between the two atria: the right atrium mirrors the left atrium.

Quantitative assessment of left atrial scar using high-density voltage mapping and a novel automated voltage analysis tool.

PURPOSE: Left atrial (LA) fibrosis plays an important role in the pathogenesis and perpetuation of atrial fibrillation (AF). It may be identified by bipolar voltage (BiV) mapping, but quantification of fibrosis which previously relied on visual estimation of scar has been shown to be inaccurate. Our aim was to use a novel automated voltage histogram analysis (VHA) tool to quantify LA scar burden accurately in patients with AF. METHODS: LA voltage was assessed in 100 consecutive patients undergoing first pulmonary vein isolation (PVI) for paroxysmal or persistent AF using a circular multielectrode catheter to create high-density LA BiV maps which were analysed using the VHA tool after the procedure. RESULTS: High-density electro-anatomic maps took 10 min to create and contained a median of 1049 points. The VHA algorithm accurately quantified the burden of Diseased LA Tissue (≤ 0.5 mV) and Dense LA Scar (≤ 0.2 mV) with a median of 17.8% and 3.5% respectively. A quartile classification was applied based on diseased LA tissue burden. Patients in class IV with the highest diseased LA burden were older (p < 0.0001), more likely female (p = 0.0095), had higher CHA2DS2-VASc scores (p = 0.0024) and were more likely to have persistent rather than paroxysmal AF (p = 0.0179) than those in classes I-III. CONCLUSIONS: The VHA algorithm is able to quantify percentage surface area voltage rapidly and according to preset ranges for the first time. The algorithm offers the potential for classification of patients undergoing AF ablation into different classes of diseased LA burden, which may have diagnostic, therapeutic and prognostic implications.

The management of cardiac implantable electronic device lead perforations: a multicentre study.

AIMS: Lead perforation is a rare, well-known complication of cardiac implantable electronic device (CIED) implants, whose management is mostly not evidence-based. Main management strategies include conservative approach based on clinical and lead function follow-up vs. routine invasive lead revision approach. This study compared the complications of both strategies by composite endpoint, including recurrent perforation-related symptoms, recurrent pericardial effusion (PEf), lead dysfunction, and device infection during 12 month follow-up. METHODS AND RESULTS: Multicentre retrospective analysis, inquiring data from imaging studies, device interrogation, pericardiocentesis, and clinical charts of patients with suspected perforating leads between 2007 and 2014 in five hospitals. All cases were reviewed by electrophysiologist and defined as definite perforations by suggestive symptoms along with lead perforation on imaging, bloody PEf on pericardiocentesis shortly after implant, or right ventricular (RV) lead non-capture along with diaphragmatic stimulation upon bipolar pacing. Clinical outcomes associated with both management approaches were compared, with respect to the composite endpoint. The study included 48 definitive perforation cases: 22 managed conservatively and 26 via lead revision. Conservative management was associated with an increased composite endpoint compared with lead revision (8/22 vs. 1/26; P = 0.007). The dominant complication among the conservative cohort was appearance of cardiac tamponade during follow-up; 5/6 occurring in cases which presented with no or only mild PEf and were treated by antiplatelets/coagulants during or shortly after CIED implantation. CONCLUSION: A conservative management of CIED lead perforation is associated with increased complications compared with early lead revision. Lead revision may be the preferred management particularly in patients receiving antiplatelets/coagulants.

Increased perforation risk with an MRI-conditional pacing lead: a single-center study.

BACKGROUND: Magnetic resonance imaging (MRI) has been considered contraindicated in patients with cardiac pacemakers (PPMs). Recently, Medtronic (MDT) MRI SureScan PPM (Medtronic Inc., Minneapolis, MN, USA) and leads were introduced into clinical practice in the United States of America. OBJECTIVE: To compare MDT CapSureFix 5086 MRI SureScan lead-associated perforation and dislodgement rates with MDT non-MRI SureScan active fixation leads. METHODS: We retrospectively analyzed the records of all patients implanted with MDT CapSureFix 5086 MRI SureScan leads as well as all patients implanted with MDT 4076 and 5076 leads at our institution from April 2011 to April 2014. RESULTS: Four of 72 patients implanted with MDT CapSureFix 5086 MRI SureScan leads (5.5%) had evidence of lead perforation, necessitating pericardiocentesis in three cases and lead revision in one case. Three of the four perforations were delayed perforations, presenting more than 3 weeks postimplant. Two patients implanted with MDT CapSureFix 5086 MRI SureScan leads (2.8%) had lead dislodgement. Of 420 patients implanted with MDT non-MRI SureScan leads, there were two perforations (0.47%) and four dislodgements (0.9%). There were significantly increased lead perforations associated with MDT CapSureFix 5086 MRI SureScan leads (P = 0.005) and a nonsignificant trend toward increased dislodgements (P = 0.18) when compared with MDT non-MRI SureScan leads. CONCLUSION: In contradiction to prior studies, this retrospective study suggests an increased perforation rate with MDT CapSureFix 5086 MRI SureScan leads. Most perforations were delayed perforations, presenting more than 3 weeks postimplant. Higher volume prospective studies with longer follow-up are needed to confirm our findings.

The Brady Bunch? New evidence for nominative determinism in patients' health: retrospective, population based cohort study.

OBJECTIVE: To ascertain whether a name can influence a person's health, by assessing whether people with the surname "Brady" have an increased prevalence of bradycardia. DESIGN: Retrospective, population based cohort study. SETTING: One university teaching hospital in Dublin, Ireland. PARTICIPANTS: People with the surname "Brady" in Dublin, determined through use of an online telephone directory. MAIN OUTCOME MEASURE: Prevalence of participants who had pacemakers inserted for bradycardia between 1 January 2007 and 28 February 2013. RESULTS: 579 (0.36%) of 161,967 people who were listed on the Dublin telephone listings had the surname "Brady." The proportion of pacemaker recipients was significantly higher among Bradys (n=8, 1.38%) than among non-Bradys (n=991, 0.61%; P=0.03). The unadjusted odds ratio (95% confidence interval) for pacemaker implantation among individuals with the surname Brady compared with individuals with other surnames was 2.27 (1.13 to 4.57). CONCLUSIONS: Patients named Brady are at increased risk of needing pacemaker implantation compared with the general population. This finding shows a potential role for nominative determinism in health.

Contrast-induced acute kidney injury: how much contrast is safe?

Iodinated contrast media (CM) are used in many investigations that a patient may undergo during the course of an in-patient stay. For the vast majority of patients, exposure to CM has no sequelae; however, in a small percentage, it can result in a worsening in renal function termed contrast-induced acute kidney injury (CI-AKI). CI-AKI is one of the leading causes of in-hospital renal dysfunction. It is associated with a significant increase in morbidity and mortality as well as an increased length of hospital stay and costs. Unfortunately, the results of extensive research into pharmacological inventions to prevent CI-AKI remain disappointing. In this article, we briefly outline the pathophysiological mechanisms by which iodinated CM may cause CI-AKI and discuss the evidence for reducing CI-AKI by limiting contrast volumes. In particular, we review the data surrounding the use of contrast volume to glomerular filtration rate ratios, which can be used by clinicians to effectively lower the incidence of CI-AKI in their patients.