Jeffrey S. Osborn

Atrial fibrillation is independently associated with senile, vascular, and Alzheimer's dementia

BACKGROUND The aging population has resulted in more patients living with cardiovascular disease, such as atrial fibrillation (AF). Recent focus has been placed on understanding the long-term consequences of chronic cardiovascular disease, such as a potential increased risk of dementia. OBJECTIVE This study sought to determine whether there is an association between AF and dementia and whether their coexistence is an independent marker of risk. METHODS A total of 37,025 consecutive patients from the large ongoing prospective Intermountain Heart Collaborative Study database were evaluated and followed up for a mean of 5 years for the development of AF and dementia. Dementia was sub-typed into vascular (VD), senile (SD), Alzheimers (AD), and nonspecified (ND). RESULTS Of the 37,025 patients with a mean age of 60.6 +/- 17.9 years, 10,161 (27%) developed AF and 1,535 (4.1%) developed dementia (179 VD, 321 SD, 347 AD, 688 ND) during the 5-year follow-up. Patients with dementia were older and had higher rates of hypertension, coronary artery disease, renal failure, heart failure, and prior strokes. In age-based analysis, AF independently was significantly associated with all dementia types. The highest risk was in the younger group (<70). After dementia diagnosis, the presence of AF was associated with a marked increased risk of mortality (VD: hazard ratio [HR] = 1.38, P = .01; SD: HR = 1.41, P = .001; AD: HR = 1.45; ND: HR = 1.38, P <.0001). CONCLUSION AF was independently associated with all forms of dementia. Although dementia is strongly associated with aging, the highest risk of AD was in the younger group, in support of the observed association. The presence of AF also identified dementia patients at high risk of death.

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.

Warfarin Is Not Needed in Low‐Risk Patients Following Atrial Fibrillation Ablation Procedures

Background: The recently published HRS/EHRA/ECAS AF Ablation Consensus Statement recommended that warfarin should be used for at least 2 months following an AF ablation in all patients regardless of stroke risk factors. The objective of the study was to assess outcomes based upon anticoagulation practice after atrial fibrillation (AF) ablation to determine relative risk of a strategy of aspirin only in low‐risk patients.

Relation of Bisphosphonate Therapies and Risk of Developing Atrial Fibrillation

Bisphosphonates comprise the most common treatment for patients with osteoporosis and fracture risk. Large randomized trials have shown that these therapies may increase the risk of atrial fibrillation (AF). Controversy over the arrhythmia risk prompted the Federal Drug Administration to recently pursue an ongoing safety review to determine the cardiac risk across the entire drug class. Study patients came from 2 large prospective databases (ongoing registry of consecutive patients who underwent coronary angiography and the Intermountain Healthcare health plans database). Medical details regarding bisphosphonate use and cardiovascular risk factors were abstracted from the records. End points included AF, myocardial infarction, and death. In the angiographic database (n = 9,623), patients treated with bisphosphonates were older and more likely to have hypertension, a previous myocardial infarction, heart failure, and osteoporosis. Over 1,481 +/- 1,024 days we found no increased risk of AF in the drug-treated group (hazard ratio 0.90, 95% confidence interval 0.48 to 1.68, p = 0.74). In the Intermountain Healthcare health plans database (n = 37,485), patients treated with bisphosphonates were older and were more likely to have hyperlipidemia and osteoporosis. Over 1,667.5 +/- 557.0 days, there was no increased risk of AF (hazard ratio 0.82, 95% confidence interval 0.66 to 1.01, p = 0.63). In the 2 databases there was no statistical difference in long-term rates of myocardial infarction or mortality. In conclusion, in a long-term study of >47,000 patients, we were unable to find an association between bisphosphonate therapy and AF. However, patients who received bisphosphonates were older and had more cardiovascular disease that we suspect accounts for the increased arrhythmia risk reported in other trials.

Ranolazine Reduces Ventricular Tachycardia Burden and ICD Shocks in Patients with Drug‐Refractory ICD Shocks

Background:  There are limited options for patients who present with antiarrhythmic‐drug (AAD)‐refractory ventricular tachycardia (VT) with recurrent implantable cardioverter defibrillator (ICD) shocks. Ranolazine is a drug that exerts antianginal and antiischemic effects and also acts as an antiarrhythmic in isolation and in combination with other class III medications. Ranolazine may be an option for recurrent AAD‐refractory ICD shocks secondary to VT, but its efficacy, outcomes, and tolerance are unknown.

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.

Warfarin Knowledge in Patients with Atrial Fibrillation: Implications for Safety, Efficacy, and Education Strategies

Background: Multiple factors influence warfarin metabolism and can significantly affect the risk of adverse events. The extent to which patients understand the modifiable factors that impact on warfarin safety and efficacy is unclear. Methods: A 52-item questionnaire related to knowledge of warfarin was administered to patients with atrial fibrillation in a face-to-face interview with a dietitian. Results were compiled based on five categories: general warfarin knowledge, compliance, drug interactions, herbal or vitamin interactions, and diet. Results: 100 patients were surveyed. Stroke risk factors included hypertension (57%), heart failure (36%), age >75 years (33%), diabetes (22%), and prior stroke/transient ischemic attack (29%). The majority were either high-school (49%) or college graduates (27%). Ten (10%) had a stroke while on warfarin, 11 (11%) had a blood transfusion, and 26 (26%) had at least one fall. The percentages correct for questionnaire items in the five categories were as follows: general knowledge (62%), compliance (71%), drug interactions (17%), herbal or vitamin interactions (7%), and diet (23%). Neither education level nor duration of therapy correlated with warfarin knowledge. Patients at highest risk of stroke had very low knowledge scores in general. Discussion: Patients on warfarin have a poor general understanding of the medication, particularly those at highest risk of stroke.

Image integration using intracardiac ultrasound and 3D reconstruction for scar mapping and ablation of ventricular tachycardia.

Background: Ablation of ventricular tachycardia (VT) reduces implantable cardioverter defibrillator shocks. Intracardiac ultrasound (ICE) can visualize and quantify the function of all left ventricular wall segments. We thus hypothesized that ICE could identify scar tissue and provide a guide to facilitate substrate‐guided VT ablation.

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.