Charles Mallender

Atrial fibrillation ablation patients have long-term stroke rates similar to patients without atrial fibrillation regardless of CHADS2 score

BACKGROUND Atrial fibrillation (AF) is a leading cause of total and fatal ischemic stroke. Stroke risk after AF ablation appears to be favorably affected; however, it is largely unknown whether the benefit extends to all stroke CHADS2 risk profiles of AF patients. OBJECTIVE To determine if ablation of atrial fibrillation reduces stroke rates in all risk groups. METHODS A total of 4212 consecutive patients who underwent AF ablation were compared (1:4) with 16,848 age-/sex-matched controls with AF (no ablation) and to 16,848 age-/sex-matched controls without AF. Patients were enrolled from the large ongoing prospective Intermountain Atrial Fibrillation Study and were followed for at least 3 years. RESULTS Of the 37,908 patients, the mean age was 65.0 ± 13 years and 4.4% (no AF), 6.3% (AF, no ablation), and 4.5% (AF ablation) patients had a prior stroke (P < .0001). The profile of CHADS2 scores between comparative groups was similar: 0-1 (69.3%, no AF; 62.3%, AF, no ablation; 63.6%, AF ablation), 2-3 (26.5%, no AF; 29.7%, AF, no ablation; 28.7%, AF ablation), and ≥4 (4.3%, no AF; 8.0%, AF, no ablation; 7.7%, AF ablation). A total of 1296 (3.4%) patients had a stroke over the follow-up period. Across all CHADS2 profiles and ages, AF patients with ablation had a lower long-term risk of stroke compared to patients without ablation. Furthermore, AF ablation patients had similar long-term risks of stroke across all CHADS2 profiles and ages compared to patients with no history of AF. CONCLUSIONS In our study populations, AF ablation patients have a significantly lower risk of stroke compared to AF patients who do not undergo ablation independent of baseline stroke risk score.

Time outside of therapeutic range in atrial fibrillation patients is associated with long-term risk of dementia

BACKGROUND The mechanisms behind the association of atrial fibrillation (AF) and dementia are unknown. One possibility is that exposure to chronic microembolism or microbleeds results in repetitive cerebral injury that is manifest by cognitive decline. OBJECTIVE The purpose of this study was to test the hypothesis that AF patients with a low percentage of time in the therapeutic range (TTR) are at higher risk for dementia due to under- or overanticoagulation. METHODS Patients anticoagulated with warfarin (target international normalized ratio [INR] 2-3), managed by the Intermountain Healthcare Clinical Pharmacist Anticoagulation Service with no history of dementia or stroke/transient ischemic attack, were included in the study. The primary outcome was dementia incidence defined by ICD-9 codes. Percent time in TTR was calculated using the method of linear interpolation and stratified as >75%, 51%-75%, 26%-50%, and ≤25%. Multivariable Cox hazard regression was used to determine dementia incidence by percentage categories of TTR. RESULTS A total of 2605 patients (age 73.7 ± 10.8 years, 1408 [54.0%] male) were studied. The CHADS2 score distribution was 0: 216 (8.3%); 1: 579 (22.2%); 2: 859(33.0%); 3: 708 (27.2%); and ≥4: 243 (9.3%). The percent TTR averaged 63.1 ± 21.3, with percent INR <2.0: 25.6% ± 17.9% and percent INR >3.0: 16.2% ± 13.6%. Dementia was diagnosed in 109 patients (4.2%) (senile: 37 [1.4%]; vascular: 8 [0.3%]; Alzheimer: 64 (2.5%]). After adjustment, decreasing categories of percent TTR were associated with increased dementia risk (vs >75%): <25%: hazard ratio (HR) 5.34, P < .0001; 26%-50%: HR 4.10, P < .0001; and 51%-75%: HR = 2.57, P = .001. CONCLUSION Quality of anticoagulation management represented as percent TTR among AF patients without dementia was associated with dementia incidence. These data support the possibility of chronic cerebral injury as a mechanism that underlies the association of AF and dementia.

The impact of risk score (CHADS2 versus CHA2DS2-VASc) on long-term outcomes after atrial fibrillation ablation

BACKGROUND Risk stratification tools are needed to select the right candidates for catheter ablation of atrial fibrillation (AF). Both the CHADS2 and CHA2DS2-VASc scores have utility in predicting AF-related outcomes and guiding anticoagulation treatment. OBJECTIVE We sought to determine whether these risk scores predict long-term outcomes after AF ablation and whether one risk score provides comparatively superior performance. METHODS CHADS2 and CHA2DS2-VASc scores were calculated in 2179 patients who underwent a first ablation procedure for AF enrolled in the Intermountain Heart Collaborative Study. CHADS2 and CHA2DS2-VASc scores were categorized as 0-1, 2-4, and ≥5. Patient outcomes were analyzed over 5 years for AF/atrial flutter recurrence and major adverse cardiovascular events (MACE: composite of death, stroke, and heart failure hospitalization). RESULTS The mean age was 65.7 ± 10.5 years, and 61.1% were men. Both scores incrementally predicted risk of AF recurrence, stroke, heart failure, and death at 5 years. Increasing CHADS2 (hazard ratio [HR] 1.19; P < .001) and CHA2DS2-VASc (HR 1.15; P < .0001) scores were both associated with AF/atrial flutter recurrence. The results were similar for MACE where increasing CHADS2 (HR 1.54; P < .0001) and CHA2DS2-VASc (HR 1.32; P < .0001) scores were associated with risk. When CHADS2 and CHA2DS2-VASc scores were modeled together, only CHA2DS2-VASc scores significantly predicted AF recurrence (HR 1.13; P = .001), but both were associated with MACE. CONCLUSION Both the CHADS2 and CHA2DS2-VASc scores were excellent in stratifying patients for 5-year outcomes after AF ablation. However, the CHA2DS2-VASc score was superior to the CHADS2 score in predicting AF recurrence and AF-related morbidities.

Five-Year Outcomes of Catheter Ablation in Patients with Atrial Fibrillation and Left Ventricular Systolic Dysfunction

Catheter ablation of atrial fibrillation (AF) is an established therapy for symptomatic patients. The long‐term efficacy and impact of catheter ablation among patients with severe systolic heart failure (SHF) requires additional study to understand if outcomes achieved at 1 year are maintained and mechanisms of AF recurrence.

Patients treated with catheter ablation for ventricular tachycardia after an ICD shock have lower long-term rates of death and heart failure hospitalization than do patients treated with medical management only

BACKGROUND Ventricular arrhythmias in patients with implantable cardioverter-defibrillators (ICDs) adversely affect outcomes. Antiarrhythmic approaches to ventricular tachycardia (VT) have variable efficacy and may increase risk of ventricular arrhythmias, worsening cardiomyopathy, and death. Comparatively, VT ablation is an alternative approach that may favorably affect outcomes. OBJECTIVE To further explore the effect on long-term outcomes after catheter ablation of VT, we compared patients with history of ICD shocks who did not undergo ablation, patients with a history of ICD shocks that underwent ablation, and patients with ICDs who had no history of ICD shocks. METHODS A total of 102 consecutive patients with structural heart disease who underwent VT ablation for recurrent ICD shocks were compared with 2088 patients with ICDs and no history of appropriate shocks and 817 patients with ICDs and a history of appropriate shocks for VT or ventricular fibrillation. Outcomes considered were mortality, heart failure hospitalization, atrial fibrillation, and stroke/transient ischemic attack. RESULTS The mean age of 3007 patients was 65.4 ± 13.9 years. Over long-term follow-up, 866 (28.8%) died, 681 (22.7%) had a heart failure admission, 706 (23.5%) developed new-onset atrial fibrillation, and 224 (7.5%) had a stroke. The multivariate-adjusted risks of deaths and heart failure hospitalizations were higher in patients with history of ICD shocks who were treated medically than in patients with ICDs and no history of shock (hazard ratio [HR] 1.45; P < .0001 vs HR 2.00; P < .0001, respectively). The multivariate-adjusted risks were attenuated after VT ablation with death and heart failure hospitalization rates similar to those of patients with no shock (HR 0.89; P = .58 vs HR 1.38; P = .09, respectively). A similar nonsignificant trend was seen with stroke/transient ischemic attack. CONCLUSIONS Patients treated with VT ablation after an ICD shock have a significantly lower risk of death and heart failure hospitalization than did patients managed medically only. The adverse event rates after VT ablation were similar to those of patients with ICDs but without VT.

A Comparison of Remote Magnetic Irrigated Tip Ablation versus Manual Catheter Irrigated Tip Catheter Ablation With and Without Force Sensing Feedback.

Remote magnetic navigation (RMN) and contact force (CF) sensing technologies have been utilized in an effort to improve safety and efficacy of catheter ablation. A comparative analysis of the relative short‐ and long‐term outcomes of AF patients has not been performed. As such, we comparatively evaluated the safety and efficacy of these technologies.

The Impact of Age on 5-Year Outcomes After Atrial Fibrillation Catheter Ablation

Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach in symptomatic patients. Many studies have shown that age has little to no impact on outcomes during the first year after ablation. However, AF is a disease of aging and age‐based substrate for arrhythmia is likely to progress. To this regard, we examined patients with 5‐year outcome data following an index AF ablation procedure to define the impact of age on long‐term outcomes.

Percent Time With a Supratherapeutic INR in Atrial Fibrillation Patients Also Using an Antiplatelet Agent Is Associated With Long‐Term Risk of Dementia

Patients with atrial fibrillation (AF) are at higher risk of developing dementia. AF patients treated with warfarin with poor time in therapeutic ranges are significantly more likely to develop dementia. AF patients are also frequently treated with antiplatelet agents due to coexistent vascular disease. We hypothesize that AF patients with anticoagulation and antiplatelet therapies will be at higher risk of dementia, particularly with chronic exposure to over‐anticoagulation.

Atrial Fibrillation Patients Treated With Long‐Term Warfarin Anticoagulation Have Higher Rates of All Dementia Types Compared With Patients Receiving Long‐Term Warfarin for Other Indications

Background The mechanisms behind the association of atrial fibrillation (AF) and dementia are unknown. We previously found a significantly increased risk of dementia in AF patients taking warfarin with a low percentage of time in therapeutic range. The purpose of this study was to determine the extent to which AF itself increases dementia risk, in addition to long‐term anticoagulation exposure. Methods and Results A total of 10 537 patients anticoagulated with warfarin (target INR 2–3), managed by the Clinical Pharmacist Anticoagulation Service with no history of dementia were included. Warfarin indication was for AF (n=4460), thromboembolism (n=5868), and mechanical heart valve(s) (n=209). Patients in the latter 2 categories were included only if they had no prior history of AF. The primary outcome was dementia. Patients with AF were older and had higher rates of hypertension, diabetes, heart failure, and stroke. AF patients experienced higher rates of total dementia (5.8% versus 1.6%, P<0.0001), Alzheimer disease (2.8% versus 0.9%, P<0.0001), and vascular dementia (1.0% versus 0.2%, P<0.0001). A propensity analysis of 6030 patients was performed to account for baseline demographics differences. Long‐term risk of dementia remained significant in AF patients compared with matched non‐AF patients (total dementia: hazard ratio [HR]=2.42 [1.85–3.18], P<0.0001; Alzheimer: HR=2.04 [1.40–2.98], P<0.0001; senile: HR=2.46 [1.58–3.86], P<0.0001). Low percent therapeutic range compared with a higher percent therapeutic range was associated with dementia risk in both AF (26–50% versus >75%: HR=2.51, P=0.005) and non‐AF groups (≤25% versus >75%: HR=3.92, P<0.0001). Conclusions The presence of AF significantly increases risk of dementia, including Alzheimers disease, compared with matched patients receiving warfarin anticoagulation for other reasons. Quality of anticoagulation management remains an important risk factor for dementia in all patients.

Long-Term Natural History of Adult Wolff–Parkinson–White Syndrome Patients Treated With and Without Catheter Ablation

Background—There are a paucity of data about the long-term natural history of adult Wolff–Parkinson–White syndrome (WPW) patients in regard to risk of mortality and atrial fibrillation. We sought to describe the long-term outcomes of WPW patients and ascertain the impact of ablation on the natural history. Methods and Results—Three groups of patients were studied: 2 WPW populations (ablation: 872, no ablation: 1461) and a 1:5 control population (n=11 175). Long-term mortality and atrial fibrillation rates were determined. The average follow-up for the WPW group was 7.9±5.9 (median: 6.9) years and was similar between the ablation and nonablation groups. Death rates were similar between the WPW group versus the control group (hazard ratio, 0.96; 95% confidence interval, 0.83–1.11; P=0.56). Nonablated WPW patients had a higher long-term death risk compared with ablated WPW patients (hazard ratio, 2.10; 95% confidence interval: 1.50–20.93; P<0.0001). Incident atrial fibrillation risk was higher in the WPW group compared with the control population (hazard ratio, 1.55; 95% confidence interval, 1.29–1.87; P<0.0001). Nonablated WPW patients had lower risk than ablated patients (hazard ratio, 0.39; 95% confidence interval, 0.28–0.53; P<0.0001). Conclusions—Long-term mortality rates in WPW patients are low and similar to an age-matched and gender-matched control population. WPW patients that underwent the multifactorial process of ablation had a lower mortality compared to nonablated WPW patients. Atrial fibrillation rates are high long-term, and ablation does not reduce this risk.