Characteristics and outcomes of patients with symptomatic chronic myocardial injury in a Tanzanian emergency department: A prospective observational study.

BACKGROUND: Chronic myocardial injury is a condition defined by stably elevated cardiac biomarkers without acute myocardial ischemia. Although studies from high-income countries have reported that chronic myocardial injury predicts adverse prognosis, there are no published data about the condition in sub-Saharan Africa. METHODS: Between November 2020 and January 2023, adult patients with chest pain or shortness of breath were recruited from an emergency department in Moshi, Tanzania. Medical history and point-of-care troponin T (cTnT) assays were obtained from participants; those whose initial and three-hour repeat cTnT values were abnormally elevated but within 11% of each other were defined as having chronic myocardial injury. Mortality was assessed thirty days following enrollment. RESULTS: Of 568 enrolled participants, 81 (14.3%) had chronic myocardial injury, 73 (12.9%) had acute myocardial injury, and 412 (72.5%) had undetectable cTnT values. Of participants with chronic myocardial injury, the mean (± sd) age was 61.5 (± 17.2) years, and the most common comorbidities were CKD (n = 65, 80%) and hypertension (n = 60, 74%). After adjusting for CKD, thirty-day mortality rates (38% vs. 36%, aOR 1.03, 95% CI: 0.52-2.03, p = 0.931) were similar between participants with chronic myocardial injury and those with acute myocardial injury, but significantly greater (38% vs. 13.6%, aOR 3.63, 95% CI: 1.98-6.65, p<0.001) among participants with chronic myocardial injury than those with undetectable cTnT values. CONCLUSION: In Tanzania, chronic myocardial injury is a poor prognostic indicator associated with high risk of short-term mortality. Clinicians practicing in this region should triage patients with stably elevated cTn levels in light of their increased risk.

Natural history of echocardiographic changes in atrial fibrillation: A case-controlled study of longitudinal remodeling.

BACKGROUND: Atrial fibrillation (AF) can be a cause and consequence of cardiac remodeling. The natural history of remodeling associated with AF is incompletely described. OBJECTIVE: The purpose of this study was to describe the frequency and timing of AF-associated echocardiographic changes. METHODS: Patients within the Duke University Health System with ≥2 transthoracic echocardiograms (TTEs) performed between 2005 and 2018 were evaluated. Patients with AF and normal baseline TTEs were matched to patients without AF on year of TTE, age, and CHA2DS2-VASc score. Frequency and timing of changes in chamber size, ventricular function, mitral regurgitation, and all-cause mortality were compared over 5 years of follow-up. RESULTS: The cohort included 3299 patients with AF at baseline and 7613 controls without AF. Normal baseline TTEs were acquired from 730 of patients with AF; 727 of these patients were matched to controls without AF. Patients with AF had higher rates of left atrial enlargement (hazard ratio [HR] 1.53; 95% confidence interval 1.27-1.85; P < .001), left ventricular (LV) systolic dysfunction (HR 1.80; 95% confidence interval 1.00-3.26; P = .045), LV diastolic dysfunction (HR 1.51; 95% confidence interval 1.08-2.10; P = .01), and moderate or greater mitral regurgitation (HR 2.09; 95% confidence interval 1.27-3.43; P = .003) than did controls. Atrial enlargement, systolic dysfunction, and mitral regurgitation surpassed the rates seen in controls within 6-12 months, whereas differences in diastolic dysfunction emerged at 24 months. There were no differences in ventricular sizes or mortality. CONCLUSION: AF is associated with higher rates of left atrial enlargement, LV systolic and diastolic dysfunction, and mitral regurgitation that typically manifest within 6-24 months of diagnosis. The natural history of cardiac remodeling in patients with AF may inform treatment decisions and facilitate patient-tailored care.

Electrocardiographic parameters associated with pacemaker induced cardiomyopathy.

BACKGROUND: Chronic right ventricular (RV) pacing can induce left ventricular (LV) dyssynchrony and cause pacemaker induced cardiomyopathy (PiCM). Identifying which patients are at risk for PiCM is limited. METHODS: Patients receiving RV-only permanent pacemakers (PPMs) at Duke University Medical Center between 2011 and 2017 who had normal baseline ejection fractions (EFs) were identified. Patients who developed a subsequent decrease in EF, died, or underwent cardiac resynchronization therapy, left ventricular assist device, or heart transplant without a competing cause were considered as the primary endpoint. Pre-PPM and post-PPM electrocardiograms (ECGs) were analyzed to extract scalar measurements including the lead one ratio (LOR) as well as advanced-ECG (A-ECG) features to identify predictors of PiCM. Traditional and penalized Cox regression were used to identify variables predictive of the primary endpoint. RESULTS: Pre-PPM ECGs were evaluated for 404 patients of whom 140 (35%) experienced the primary endpoint. Predictors included female sex (hazard ratio [HR] 1.14), a T' wave in V6 (HR 1.31), a P' wave in aVL (HR 0.88), and estimated glomerular filtration rate (HR 0.88). Post-PPM ECGs were evaluated for 228 patients for whom 94 (41%) experienced the primary endpoint. Predictors included female sex (HR 0.50), age (HR 1.06), and a history of congestive heart failure (HR 1.63). Neither LOR nor A-ECG parameters were strong predictors of the primary endpoint. CONCLUSIONS: Baseline and paced ECG data provide limited insight into which patients are at high risk for developing PiCM.

Acute echocardiographic and hemodynamic response to his-bundle pacing in patients with first-degree atrioventricular block.

BACKGROUND: Atrial pacing and right ventricular (RV) pacing are both associated with adverse outcomes among patients with first-degree atrioventricular block (1°AVB). His-bundle pacing (HBP) provides physiological activation of the ventricle and may be able to improve both atrioventricular (AV) and inter-ventricular synchrony in 1°AVB patients. This study evaluates the acute echocardiographic and hemodynamic effects of atrial, atrial-His-bundle sequential (AH), and atrial-ventricular (AV) sequential pacing in 1°AVB patients. METHODS: Patients with 1°AVB undergoing atrial fibrillation ablation were included. Following left atrial (LA) catheterization, patients underwent atrial, AH- and AV-sequential pacing. LA/left ventricular (LV) pressure and echocardiographic measurements during the pacing protocols were compared. RESULTS: Thirteen patients with 1°AVB (mean PR 221 ± 26 ms) were included. The PR interval was prolonged with atrial pacing compared to baseline (275 ± 73 ms, p = .005). LV ejection fraction (LVEF) was highest during atrial pacing (62 ± 11%), intermediate with AH-sequential pacing (59 ± 7%), and lowest with AV-sequential pacing (57 ± 12%) though these differences were not statistically significant. No significant differences were found in LA or LV mean pressures or LV dP/dT. LA and LV volumes, isovolumetric times, electromechanical delays, and global longitudinal strains were similar across pacing protocols. CONCLUSION: Despite pronounced PR prolongation, the acute effects of atrial pacing were not significantly different than AH- or AV-sequential pacing. Normalizing atrioventricular and/or inter-ventricular dyssynchrony did not result in acute improvements in cardiac output or loading conditions.

Diagnosis-to-ablation time predicts recurrent atrial fibrillation and rehospitalization following catheter ablation.

BACKGROUND: Wait times for catheter ablation in patients with symptomatic atrial fibrillation (AF) may influence clinical outcomes. OBJECTIVE: This study examined the relationship between the duration from AF diagnosis to ablation, or diagnosis-to-ablation time (DAT), on the clinical response to catheter ablation in a large nationwide cohort of patients. METHODS: We identified patients with new AF who underwent catheter ablation between January 2014 and December 2017 using the IBM MarketScan databases. Cox proportional hazard models were used to estimate the strength of the association between DAT and the outcomes of AF recurrence and hospitalization at 1 year postablation. RESULTS: Among 11,143 AF patients who underwent ablation, the median age was 59 years, 31% were female, and the median CHA2DS2-VASc score was 2. Median DAT was 5.5 (2.6, 13.1) months. At 1 year postablation, 10.0% (n = 1116) developed recurrent AF. For each year increase in DAT, the risk of AF recurrence increased by 20% after adjustment for baseline comorbidities and medications (hazard ratio [HR] 1.20, 95% confidence interval [CI] 1.11-1.30). A longer DAT was associated with an increased risk of hospitalization (HR 1.08 per DAT year, 95% CI 1.02-1.15). DAT was a stronger predictor of AF recurrence postablation than traditional clinical risk factors, including age, prior heart failure, or renal failure. CONCLUSION: Increasing duration between AF diagnosis and catheter ablation is associated with higher AF recurrence rates and all-cause hospitalization. Our findings are consistent with a growing body of evidence supporting the benefits of prioritizing early restoration of sinus rhythm.

Healthcare-seeking behaviour, barriers to care and predictors of symptom improvement among patients with cardiovascular disease in northern Tanzania.

BACKGROUND: Little is known about healthcare-seeking behaviour and barriers to care for cardiovascular disease (CVD) in sub-Saharan Africa. METHODS: Emergency department patients in Tanzania with acute CVD were prospectively enrolled. Questionnaires were administered at enrollment and 30 d later. RESULTS: Of 241 patients, 186 (77.2%) had visited another facility for the same illness episode (median symptom duration prior to presentation was 7 d) and 82 (34.0%) reported that they were initially unaware of the potential seriousness of their symptoms. Of the 208 (86.3%) patients completing follow-up, 16 (7.7%) had died, 38 (18.3%) had visited another facility for persistent symptoms, 99 (47.6%) felt they understood their diagnosis, 87 (41.8%) felt they understood their treatment and 11 (7.8%) could identify any of their medications. Predictors of 30 d survival with symptom improvement included medication compliance (p<0.001), understanding the diagnosis (p=0.007), understanding the treatment (p<0.001) and greater CVD knowledge (p=0.008). CONCLUSIONS: Patients with CVD in Tanzania usually visit multiple facilities for the same illness episode, typically after prolonged delays. Only a minority understand their diagnosis and treatment, and such understanding is correlated with survival with symptom improvement. Patient-centred interventions are needed to improve the quality of cardiovascular care in Tanzania.

The prevalence, management, and thirty-day outcomes of symptomatic atrial fibrillation in a Tanzanian emergency department.

INTRODUCTION: Data describing atrial fibrillation (AF) care in emergency centres (ECs) in sub-Saharan Africa is lacking. We sought to describe the prevalence and outcomes of AF in a Tanzanian EC. METHODS: In a prospective, observational study, adults presenting with chest pain or shortness of breath to a Tanzanian EC were enrolled from January through October 2019. Participants underwent electrocardiogram testing which were reviewed by two independent physician judges to determine presence of AF. Participants were asked about their medical history and medication use at enrollment, and a follow-up questionnaire was administered via telephone thirty days later to assess mortality, interim stroke, and medication use. RESULTS: Of 681 enrolled patients, 53 (7.8%) had AF. The mean age of participants with AF was 68.1, with a standard deviation (sd) of 21.1 years, and 23 of the 53 (43.4%) being male. On presentation, none of the participants found to have AF reported a previous history of AF. The median CHADS-VASC score among participants was 4 with an interquartile range (IQR) of 2-4. No participants were taking an anticoagulant at baseline. On index presentation, 49 (92.5%) participants with AF were hospitalised with 52 (98.1%) participants completing 30-day follow-up. 18 (34%) participants died, and 5 (9.6%) suffered a stroke. Of the surviving 31 participants with AF and a CHADS-VASC score ≥ 2, none were taking other anti-coagulants at 30 days. Compared to participants without AF, participants with AF were more likely to be hospitalised (OR 5.25, 95% CI 2.10-17.95, p < 0.001), more likely to die within thirty days (OR 1.93, 95% CI 1.03-3.50, p = 0.031), and more likely to suffer a stroke within thirty days (OR 5.91, 95% CI 1.76-17.28, p < 0.001). DISCUSSION: AF is common in a Tanzanian EC, with thirty-day mortality being high, but use of evidence-based therapies is rare. There is an opportunity to improve AF care and outcomes in Tanzania.

Interpretable morphological features for efficient single-lead automatic ventricular ectopy detection.

OBJECTIVE: We designed an automatic, computationally efficient, and interpretable algorithm for detecting ventricular ectopic beats in long-term, single-lead electrocardiogram recordings. METHODS: We built five simple, interpretable, and computationally efficient features from each cardiac cycle, including a novel morphological feature which described the distance to the median beat in the recording. After an unsupervised subject-specific normalization procedure, we trained an ensemble binary classifier using the AdaBoost algorithm RESULTS: After our classifier was trained on subset DS1 of the Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) Arrhythmia database, our classifier obtained an F1 score of 94.35% on subset DS2 of the same database. The same classifier achieved F1 scores of 92.06% on the St. Petersburg Institute of Cardiological Technics (INCART) 12-lead Arrhythmia database and 91.40% on the MIT-BIH Long-term database. A phenotype-specific analysis of model performance was afforded by the annotations included in the St. Petersburg INCART Arrhythmia database CONCLUSION: The five features this novel algorithm employed allowed our ventricular ectopy detector to obtain high precision on previously unseen subjects and databases SIGNIFICANCE: Our ventricular ectopy detector will be used to study the relationship between premature ventricular contractions and adverse patient outcomes such as congestive heart failure and death.

Economic Evaluation of Catheter Ablation of Atrial Fibrillation in Patients with Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Randomized clinical trials have demonstrated that catheter ablation for atrial fibrillation in patients with heart failure with reduced ejection fraction may improve survival and other cardiovascular outcomes. METHODS: We constructed a decision-analytic Markov model to estimate the costs and benefits of catheter ablation and medical management in patients with symptomatic heart failure with reduced ejection fraction (left ventricular ejection fraction ≤35%) and atrial fibrillation over a lifetime horizon. Evidence from the published literature informed the model inputs, including clinical effectiveness data from meta-analyses. Probabilistic and deterministic sensitivity analyses were performed. A 3% discount rate was applied to both future costs and benefits. The primary outcome was the incremental cost-effectiveness ratio assessed from the US health care sector perspective. RESULTS: Catheter ablation was associated with 6.47 (95% CI, 5.89-6.93) quality-adjusted life years (QALYs) and a total cost of $105 657 (95% CI, $55 311-$191 934; 2018 US dollars), compared with 5.30 (95% CI, 5.20-5.39) QALYs and $63 040 (95% CI, $37 624-$102 260) for medical management. The incremental cost-effectiveness ratio for catheter ablation compared with medical management was $38 496 (95% CI, $5583-$117 510) per QALY gained. Model inputs with the greatest variation on incremental cost-effectiveness ratio estimates were the cost of ablation and the effect of catheter ablation on mortality reduction. When assuming a more conservative estimate of the treatment effect of catheter ablation on mortality (hazard ratio of 0.86), the estimated incremental cost-effectiveness ratio was $74 403 per QALY gained. At a willingness-to-pay threshold of $100 000 per QALY gained, atrial fibrillation ablation was found to be economically favorable compared with medical management in 95% of simulations. CONCLUSIONS: Catheter ablation in patients with heart failure with reduced ejection fraction patients and atrial fibrillation may be considered economically attractive at current benchmarks for societal willingness-to-pay in the United States.

VVI pacing with normal QRS duration and ventricular function: MOST trial findings relevant to leadless pacemakers.

BACKGROUND: Leadless pacemakers (LPs) provide ventricular pacing without the risks associated with transvenous leads and device pockets. LPs are appealing for patients who need pacing, but do not need defibrillator or cardiac resynchronization therapy. Most implanted LPs provide right ventricular pacing without atrioventricular synchrony (VVIR mode). The Mode Selection Trial in Sinus Node Dysfunction (MOST) showed similar outcomes in patients randomized to dual-chamber (DDDR) versus ventricular pacing (VVIR). We compared outcomes by pacing mode in LP-eligible patients from MOST. METHODS: Patients enrolled in the MOST study with an left ventricular ejection fraction (LVEF) >35%, QRS duration (QRSd) <120 ms and no history of ventricular arrhythmias or prior implantable cardioverter defibrillators were included (LP-eligible population). Cox proportional hazards models were used to test the association between pacing mode and death, stroke or heart failure (HF) hospitalization and atrial fibrillation (AF). RESULTS: Of the 2010 patients enrolled in MOST, 1284 patients (64%) met inclusion criteria. Baseline characteristics were well balanced across included patients randomized to DDDR (N = 630) and VVIR (N = 654). Over 4 years of follow-up, there was no association between pacing mode and death, stroke or HF hospitalization (VVIR HR 1.28 [0.92-1.75]). VVIR pacing was associated with higher risk of AF (HR 1.32 [1.08-1.61], P = .007), particularly in patients with no history of AF (HR 2.38 [1.52-3.85], P < .001). CONCLUSION: In patients without reduced LVEF or prolonged QRSd who would be eligible for LP, DDDR, and VVIR pacing demonstrated similar rates of death, stroke or HF hospitalization; however, VVIR pacing significantly increased the risk of AF development.

Concomitant changes in ventricular depolarization and repolarization and long-term outcomes of biventricular pacing.

BACKGROUND: Biventricular (BiV) pacing increases transmural repolarization heterogeneity due to epicardial to endocardial conduction from the left ventricular (LV) lead. However, limited evidence is available on concomitant changes in ventricular depolarization and repolarization and long-term outcomes of BiV pacing. Therefore, we investigated associations of BiV pacing-induced concomitant changes in ventricular depolarization and repolarization with mortality (i.e., LV assist device, heart transplantation, or all-cause mortality) and sustained ventricular arrhythmia endpoints. METHODS: Consecutive BiV-defibrillator recipients with digital preimplantation and postimplantation electrocardiograms recorded between 2006 and 2015 at Duke University Medical Center were included. We calculated changes in QRS duration and corrected JT (JTc) interval and split them by median values. For simplicity, these variables were named QRSdecreased (≤ -12 ms), QRSincreased (> -12 ms), JTcdecreased (≤22 ms), and JTcincreased (> 22 ms) and subsequently used to construct four mutually exclusive groups. RESULTS: We included 528 patients (median age, 68 years; male, 69%). No correlation between changes in QRS duration and JTc interval was observed (P = .295). Compared to QRSdecreased /JTcincreased , increased risk of the composite mortality endpoint was associated with QRSdecreased /JTcdecreased (hazard ratio [HR] = 1.62; 95% confidence interval [CI] = 1.09-2.43), QRSincreased /JTcdecreased (HR = 1.86; 95% CI = 1.27-2.71), and QRSincreased /JTcincreased (HR = 2.25; 95% CI = 1.52-3.35). No QRS/JTc group was associated with excess sustained ventricular arrhythmia risk (P = .400). CONCLUSION: Among BiV-defibrillator recipients, QRSdecreased /JTcincreased was associated with the most favorable long-term survival free of LV assist device, heart transplantation, and sustained ventricular arrhythmias. Our findings suggest that improved electrical resynchronization may be achieved by assessing concomitant changes in ventricular depolarization and repolarization.

Predicting the Development of Reduced Left Ventricular Ejection Fraction in Patients With Left Bundle Branch Block.

Left bundle branch block (LBBB) increases the likelihood of developing reduced left ventricular (LV) ejection fraction (EF) but predicting which patients with LBBB and normal LVEF will develop decreased LVEF remains challenging. Fifty patients with LBBB and normal LVEF were retrospectively identified. Clinical, electrocardiographic, and echocardiographic variables were compared between patients who developed a decreased LVEF and those who did not. A total of 16 of 50 patients developed reduced LVEF after 4.3 (SD = 2.8) years of follow-up. Baseline patient and electrocardiographic variables were similar between patients who did and did not develop decreased LVEF. Baseline LVEF was lower in patients who developed decreased LVEF than in those who did not (51.9% [SD = 2.2%] vs 54.9% [SD = 4.4%], p <0.01). Diastolic filling time (DFT) accounted for a significantly smaller percentage of the cardiac cycle in patients who developed decreased LVEF than in those who did not (35.9%, [SD = 6.9%] vs 44.4% [SD = 4.5%] p <0.01). In univariable logistic regression, DFT had a C-statistic of 0.86 (p <0.0001) for prediction of development of decreased LVEF. In conclusion, patients in whom DFT accounted for <38% of the cardiac cycle had a relative risk of developing decreased LVEF of 7.0 (95% confidence interval 3.0 to 16.0) compared to patients with DFT accounting for ≥38% of the cardiac cycle.

Machine learning does not improve upon traditional regression in predicting outcomes in atrial fibrillation: an analysis of the ORBIT-AF and GARFIELD-AF registries.

AIMS: Prediction models for outcomes in atrial fibrillation (AF) are used to guide treatment. While regression models have been the analytic standard for prediction modelling, machine learning (ML) has been promoted as a potentially superior methodology. We compared the performance of ML and regression models in predicting outcomes in AF patients. METHODS AND RESULTS: The Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) and Global Anticoagulant Registry in the FIELD (GARFIELD-AF) are population-based registries that include 74 792 AF patients. Models were generated from potential predictors using stepwise logistic regression (STEP), random forests (RF), gradient boosting (GB), and two neural networks (NNs). Discriminatory power was highest for death [STEP area under the curve (AUC) = 0.80 in ORBIT-AF, 0.75 in GARFIELD-AF] and lowest for stroke in all models (STEP AUC = 0.67 in ORBIT-AF, 0.66 in GARFIELD-AF). The discriminatory power of the ML models was similar or lower than the STEP models for most outcomes. The GB model had a higher AUC than STEP for death in GARFIELD-AF (0.76 vs. 0.75), but only nominally, and both performed similarly in ORBIT-AF. The multilayer NN had the lowest discriminatory power for all outcomes. The calibration of the STEP modelswere more aligned with the observed events for all outcomes. In the cross-registry models, the discriminatory power of the ML models was similar or lower than the STEP for most cases. CONCLUSION: When developed from two large, community-based AF registries, ML techniques did not improve prediction modelling of death, major bleeding, or stroke.

Changes in the optimal cardiac resynchronization therapy pacing configuration during physiologic stress.

BACKGROUND: Some patients with ongoing heart failure symptoms after treatment with cardiac resynchronization therapy (CRT) demonstrate QRS prolongation during exercise. We investigated whether the optimal CRT pacing configuration changes during dobutamine stress. METHODS: Seven patients undergoing CRT implantation underwent invasive LV dP/dTmax measurement during CRT pacing in 10 configurations to determine the optimal baseline pacing configuration (OPC). Measurements were repeated during dobutamine infusion. Differences in mean LV dP/dTmax between pacing configurations were compared. RESULTS: Baseline OPC differed from stress OPC in 6/7 patients. The mean (SD) LV dP/dTmax obtained during dobutamine infusion was 1140 (377) mmHg/s in AAI pacing, 1458 (448) mmHg/s in the baseline OPC, and 1656 (435) mmHg/s in the dobutamine OPC (p < 0.001 for differences). The mean increase in LV dP/dTmax obtained by changing from baseline OPC to dobutamine OPC during dobutamine infusion was 197 (338) mmHg/s (13%). The QRS duration, QRS morphology, QLV and QRV intervals did not change significantly during dobutamine infusion (all P > 0.05). CONCLUSIONS: The optimal CRT pacing configuration changes during dobutamine infusion while LV and RV activation timing does not. Further studies investigating the usefulness of automated dynamic changes to CRT pacing configuration according to physiologic condition may be warranted.

Reducing ECG Artifact From Left Ventricular Assist Device Electromagnetic Interference.

Background Left ventricular assist devices (LVADs) generate electromagnetic interference that causes high-frequency noise artifacts on 12-lead ECGs. We describe the causes of this interference and potential solutions to aid ECG interpretation in patients with LVAD. Methods and Results Waveform data from ECGs performed before and after LVAD implantation were passed through a fast Fourier transform to identify LVAD-related changes in the spectral profile. ECGs recorded in 9 patients with HeartMate II, HeartMate 3, and HeartWare LVADs were analyzed to identify the LVAD model-specific spectral patterns. Waveform data were then passed through digital low-pass and bandstop filters and redisplayed to evaluate the effect of filtering on LVAD-related electromagnetic interference. The spectral profile of patients with HeartMate II and HeartMate 3 LVADs demonstrated a prominent signal at the device-specific frequency of impeller rotation. In patients with the HeartMate 3 LVAD, 2 additional peaks were observed at the frequencies equivalent to the LVAD's artificial pulsatility rotational speeds. Patients with HeartWare devices demonstrated a prominent signal peak at a frequency equal to double their LVAD's set rotational speed. Applying a low-pass filter to a value below the observed frequency peak from the LVAD significantly improved the waveform tracing and quality of the ECG. Applying a speed-specific bandstop filter to remove the observed LVAD frequency peak also improved the clarity of the ECG without compromising physiological high-frequency signal components. Conclusions LVADs create impeller rotational speed-specific electromagnetic interference that can be ameliorated by application of low-pass or bandstop filters to improve ECG clarity.

Procedural Patterns and Safety of Atrial Fibrillation Ablation: Findings From Get With The Guidelines-Atrial Fibrillation.

BACKGROUND: Catheter ablation is an increasingly used treatment for symptomatic atrial fibrillation (AF). However, there are limited prospective, nationwide data on patient selection and procedural characteristics. This study describes patient characteristics, techniques, treatment patterns, and safety outcomes of patients undergoing AF ablation. METHODS: A total of 3139 patients undergoing AF ablation between 2016 and 2018 in the Get With The Guidelines-Atrial Fibrillation registry from 24 US centers were included. Patient demographics, medical history, procedural details, and complications were abstracted. Differences between paroxysmal and patients with persistent AF were compared using Pearson χ2 and Wilcoxon rank-sum tests. RESULTS: Patients undergoing AF ablation were predominantly male (63.9%) and White (93.2%) with a median age of 65. Hypertension was the most common comorbidity (67.6%), and patients with persistent AF had more comorbidities than patients with paroxysmal AF. Drug refractory, paroxysmal AF was the most common ablation indication (class I, 53.6%) followed by drug refractory, persistent AF (class I, 41.8%). Radiofrequency ablation with contact force sensing was the most common ablation modality (70.5%); 23.7% of patients underwent cryoballoon ablation. Pulmonary vein isolation was performed in 94.6% of de novo ablations; the most common adjunctive lesions included left atrial roof or posterior/inferior lines, and cavotricuspid isthmus ablation. Complications were uncommon (5.1%) and were life-threatening in 0.7% of cases. CONCLUSIONS: More than 98% of AF ablations among participating sites are performed for class I or class IIA indications. Contact force-guided radiofrequency ablation is the dominant technique and pulmonary vein isolation the principal lesion set. In-hospital complications are uncommon and rarely life-threatening.