Eric Sibley, Academic Advising Dean
Atrial fibrillation (AF) is treated by many types of physician specialists, including primary care physicians (PCPs). Health plans have different policies for how patients encounter these providers, and these may affect selection of AF treatment strategy.We hypothesized that healthcare plans with PCP-gatekeeping to specialist access may be associated with different pharmacologic treatments for AF.We performed a retrospective cohort study using a commercial pharmaceutical claims database. We utilized logistic regression models to compare odds of prescription of oral anticoagulant (OAC), non-vitamin K-dependent oral anticoagulant (NOAC), rate control, and rhythm control medications used to treat AF between patients with PCP-gated healthcare plans (e.g. HMO, EPO, POS) and patients with non-PCP-gated healthcare plans (e.g. PPO, CHDP, HDHP, Comprehensive) between 2007 and 2012. We also calculated median time to receipt of therapy within 90 days of index AF diagnosis.We found similar odds of OAC prescription at 90 days following new AF diagnosis in patients with PCP-gated plans compared to those with non-PCP-gated plans (OR: OAC 1.01, p=0.84; warfarin 1.05, p=0.08). Relative odds were similar for rate control (1.17, p<0.01) and rhythm control agents (0.93, p=0.03). However, PCP-gated plan patients had slightly lower likelihood of being prescribed NOACs (0.82, p=0.001) than non-gated plan patients. Elapsed time until receipt of medication was similar between PCP-gated and non-gated groups across drug classes.Pharmaceutical claims data do not suggest that PCP-gatekeeping by healthcare plans is a structural barrier to AF therapy, although it was associated with lower use of NOACs.
View details for PubMedID 30098034
To evaluate warfarin prescription, quality of international normalised ratio (INR) monitoring and of INR control in patients with atrial fibrillation (AF) and chronic kidney disease (CKD).We performed a retrospective cohort study of patients with newly diagnosed AF in the Veterans Administration (VA) healthcare system. We evaluated anticoagulation prescription, INR monitoring intensity and time in and outside INR therapeutic range (TTR) stratified by CKD.Of 123?188 patients with newly diagnosed AF, use of warfarin decreased with increasing severity of CKD (57.2%-46.4%), although it was higher among patients on dialysis (62.3%). Although INR monitoring intensity was similar across CKD strata, the proportion with TTR?60% decreased with CKD severity, with only 21% of patients on dialysis achieving TTR?60%. After multivariate adjustment, the magnitude of TTR reduction increased with CKD severity. Patients on dialysis had the highest time markedly out of range with INR <1.5 or >3.5 (30%); 12% of INR time was >3.5, and low TTR persisted for up to 3?years.There is a wide variation in anticoagulation prescription based on CKD severity. Patients with moderate-to-severe CKD, including dialysis, have substantially reduced TTR, despite comparable INR monitoring intensity. These findings have implications for more intensive warfarin management strategies in CKD or alternative therapies such as direct oral anticoagulants.
View details for DOI 10.1136/heartjnl-2016-309266
View details for Web of Science ID 000401028400006
Data regarding catheter ablation of atrial fibrillation (AF) in patients with chronic kidney disease (CKD) is limited. We therefore assessed the association of CKD with common safety and clinical outcomes in a nationwide sample of ablation recipients.Using MarketScan(®) Commercial Claims and Medicare Supplemental Databases, we evaluated 30-day safety and 1-year clinical outcomes in patients who underwent a first AF ablation procedure between 2007 and 2011. We calculated frequency of common 30-day complications and calculated frequencies, incidence rates, and Cox proportional hazards for outcomes at 1-year postablation.Of 21,091 patients included, 1,593 (7.6%) had CKD. Patients with CKD were older (64 years vs. 59 years, P < 0.001) with higher CHA2 DS2 -VASc scores (3.2 vs. 1.8, P < 0.001). At 30 days postablation, patients with CKD had similar rates of stroke/TIA (0.13% vs. 0.13%, P = 0.99), perforation/tamponade (3.2% vs. 3.1%, P = 0.83), and vascular complications (2.4% vs. 2.2%, P = 0.59) as patients without CKD, but were more likely to be hospitalized for heart failure (2.1% vs. 0.4%, P < 0.001). In multivariate analysis, there were no significant differences in hazards of AF hospitalization (adjusted HR: 1.02, 95%CI: 0.87-1.20), cardioversion (adjusted HR: 0.99, 95%CI: 0.87-1.12), or repeat AF ablation (adjusted HR: 0.89, 95%CI: 0.76-1.06) at 1 year.Among patients selected for AF ablation, those with and without CKD had similar rates of postprocedural complications although they were more likely to be re-admitted for heart failure. CKD was not independently associated with AF hospitalization, cardioversion, and repeat ablation. These findings can inform clinical decision-making in patients with AF and CKD.
View details for DOI 10.1111/jce.13118
View details for Web of Science ID 000393901900004
Sudden cardiac death is often linked with hypertrophic cardiomyopathy in young athletes, but with a divergence of study results. We performed a meta-analysis to compare the prevalence of sudden cardiac deaths associated with hypertrophic cardiomyopathy vs sudden cardiac deaths associated with structurally normal hearts.A structured search of MEDLINE was conducted for studies published from 1990 through 2014. Retrospective cohort studies, patient registries, and autopsy series examining sudden cardiac death etiology in young individuals (age ?35 years) were included. A random-effects model was applied to generate pooled summary estimates of the percentage of sudden cardiac deaths with structurally normal hearts at postmortem vs those caused by hypertrophic cardiomyopathy. Heterogeneity was assessed using I(2). Subgroup analyses were conducted based on study location, patient age groups, and population types.Thirty-four studies were included, representing a combined sample of 4605 subjects. The overall pooled percentage of sudden cardiac deaths caused by hypertrophic cardiomyopathy was 10.3% (95% confidence interval [CI], 8.0%-12.6%; I(2) = 87.2%), while sudden cardiac deaths with structurally normal hearts at death were more common (P <.001) at 26.7% (95% CI, 21.0%-32.3%; I(2) = 95.3%). In nonathlete subjects, the pooled percentage of sudden cardiac deaths associated with structurally normal hearts (30.7%; 95% CI, 23.0%-38.4%; I(2) = 96.3%) were significantly more common (P <.001) than sudden cardiac death caused by hypertrophic cardiomyopathy (7.8%; 95% CI, 5.8%-9.9%; I(2) = 80.1%). Among athletes, there was no significant difference between summary estimates of hypertrophic cardiomyopathy and structurally normal hearts (P = .57), except in Europe where structurally normal hearts were more common (P = .01).Hypertrophic cardiomyopathy is not a more common finding at death than structurally normal hearts in young subjects with sudden cardiac death. Increased attention should be directed toward identifying causes of death associated with a structurally normal heart in subjects with sudden cardiac death.
View details for DOI 10.1016/j.amjmed.2015.12.027
View details for PubMedID 26800575
The influence of race on quality of anticoagulation control is not well described. We examined the association between race, international normalized ratio (INR) monitoring intensity, and INR control in warfarin-treated patients with atrial fibrillation (AF). Using data from the Veterans Health Administration (VHA), we performed a retrospective cohort study of 184,161 patients with a new diagnosis of AF/flutter from 2004 to 2012 who received any VHA prescription within 90 days of diagnosis. The primary predictor was race, ascertained from multiple VHA and linked Medicare demographic files. The primary outcome was first-year and long-term time in therapeutic range (TTR) of INR 2.0 to 3.0. Secondary outcomes were INR monitoring intensity and warfarin persistence. Of the 116,021 patients who received warfarin in the cohort, INR monitoring intensity was similar across racial groups. However, TTR was lowest in blacks and highest in whites (first year 0.49 ± 0.23 vs 0.57 ± 0.21, p <0.001; long term 0.52 ± 0.20 vs 0.59 ± 0.18, p <0.001); 64% of whites and 49% of blacks had long-term TTR >55% (p <0.001). After adjusting for site and patient-level covariates, black race was associated with lower first-year and long-term TTRs (4.2% and 4.1% below the conditional mean, relative to whites; p <0.0001 for both). One-year warfarin persistence was slightly lower in blacks compared to whites (58% vs 60%, p <0.0001). In conclusion, in patients with AF anticoagulated with warfarin, differences in INR control are most evident among blacks, underscoring the need to determine if other types of intensive management or warfarin alternatives may be necessary to improve anticoagulation among vulnerable AF populations.
View details for DOI 10.1016/j.amjcard.2015.09.047
View details for Web of Science ID 000368048900010
View details for DOI 10.1016/j.jacep.2016.04.014
There are limited data on mortality outcomes associated with use of amiodarone in atrial fibrillation and flutter (AF).We evaluated the association of amiodarone use with mortality in patients with newly diagnosed AF using complete data from the Department of Veterans Affairs national health care system. We included patients seen in an outpatient setting within 90 days of a new diagnosis for nonvalvular AF between Veterans Affairs fiscal years 2004 and 2008. Multivariate analysis and propensity-matched Cox proportional hazards regression were used to evaluate the association of amiodarone use to death.Of 122,465 patients (353,168 person-years of follow-up, age 72.1 ± 10.3 years, 98.4% males), amiodarone was prescribed in 11,655 (9.5%). Cumulative, unadjusted mortality rates were higher for amiodarone recipients than for nonrecipients (87 vs 73 per 1,000 person-years, P < .001). However, in multivariate and propensity-matched survival analyses, there was no significant difference in mortality (multivariate hazard ratio 1.01, 95% CI 0.97-1.05, P = .51, and propensity-matched hazard ratio 1.02, 95% CI 0.97-1.07, P = .45). The hazard of death was not modified by age, sex, heart failure, kidney function, ?-blocker use, or warfarin use, but there was evidence of effect modification among patients diagnosed with AF as an inpatient versus outpatient.In a national health care system population of newly diagnosed AF, overall use of amiodarone as an early treatment strategy was not associated with mortality.
View details for DOI 10.1016/j.ahj.2015.07.023
View details for PubMedID 26542514
View details for PubMedCentralID PMC4800972
Identification of silent atrial fibrillation (AF) could prevent stroke and other sequelae.Screening for AF using continuous ambulatory electrocardiographic (ECG) monitoring can detect silent AF in asymptomatic in patients with known risk factors.We performed a single-center prospective screening study using a wearable patch-based device that provides up to 2 weeks of continuous ambulatory ECG monitoring (iRhythm Technologies, Inc.). Inclusion criteria were age ?55 years and ?2 of the following risk factors: coronary disease, heart failure, hypertension, diabetes, sleep apnea. We excluded patients with prior AF, stroke, transient ischemic attack, implantable pacemaker or defibrillator, or with palpitations or syncope in the prior year.Out of 75 subjects (all male, age 69 ± 8.0 years; ejection fraction 57% ± 8.7%), AF was detected in 4 subjects (5.3%; AF burden 28% ± 48%). Atrial tachycardia (AT) was present in 67% (?4 beats), 44% (?8 beats), and 6.7% (?60 seconds) of subjects. The combined diagnostic yield of sustained AT/AF was 11%. In subjects without sustained AT/AF, 11 (16%) had ?30 supraventricular ectopic complexes per hour.Outpatient extended ECG screening for asymptomatic AF is feasible, with AF identified in 1 in 20 subjects and sustained AT/AF identified in 1 in 9 subjects, respectively. We also found a high prevalence of asymptomatic AT and frequent supraventricular ectopic complexes, which may be relevant to development of AF or stroke. If confirmed in a larger study, primary screening for AF could have a significant impact on public health.
View details for DOI 10.1002/clc.22387
View details for PubMedID 25873476
Atrial fibrillation (AF) is one of the most common cardiac conditions treated in primary care and specialty cardiology settings, and is associated with considerable morbidity, mortality and cost. Catheter ablation, typically by electrically isolating the pulmonary veins and surrounding tissue, is more effective at maintaining sinus rhythm than conventional antiarrhythmic drug therapy and is now recommended as first-line therapy. From a value standpoint, the cost-effectiveness of ablation must incorporate the upfront procedural costs and risks with the benefits of longer term improvements in quality of life (QOL) and healthcare utilisation. Here, we present a primer on cost-effectiveness analysis (CEA), review the data on cost-effectiveness of AF ablation and outline key areas for further investigation.
View details for DOI 10.15420/aer.2014.3.3.177
View details for PubMedID 26835088
Despite endorsement of digoxin in clinical practice guidelines, there exist limited data on its safety in atrial fibrillation/flutter (AF).The goal of this study was to evaluate the association of digoxin with mortality in AF.Using complete data of the TREAT-AF (The Retrospective Evaluation and Assessment of Therapies in AF) study from the U.S. Department of Veterans Affairs (VA) healthcare system, we identified patients with newly diagnosed, nonvalvular AF seen within 90 days in an outpatient setting between VA fiscal years 2004 and 2008. We used multivariate and propensity-matched Cox proportional hazards to evaluate the association of digoxin use with death. Residual confounding was assessed by sensitivity analysis.Of 122,465 patients with 353,168 person-years of follow-up (age 72.1 ± 10.3 years, 98.4% male), 28,679 (23.4%) patients received digoxin. Cumulative mortality rates were higher for digoxin-treated patients than for untreated patients (95 vs. 67 per 1,000 person-years; p < 0.001). Digoxin use was independently associated with mortality after multivariate adjustment (hazard ratio [HR]: 1.26, 95% confidence interval [CI]: 1.23 to 1.29, p < 0.001) and propensity matching (HR: 1.21, 95% CI: 1.17 to 1.25, p < 0.001), even after adjustment for drug adherence. The risk of death was not modified by age, sex, heart failure, kidney function, or concomitant use of beta-blockers, amiodarone, or warfarin.Digoxin was associated with increased risk of death in patients with newly diagnosed AF, independent of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies. These findings challenge current cardiovascular society recommendations on use of digoxin in AF.
View details for DOI 10.1016/j.jacc.2014.03.060
View details for PubMedID 25125296
In response to unsustainably rising costs, variable quality and access to health care, and the projected insolvency of vital safety net insurance programs, the federal government has proposed important health policy and regulatory changes in the USA. The US Supreme Court's decision to uphold most of the major provisions of the Affordable Care Act will lead to some of the most sweeping government reforms on entitlements since the creation of Medicare. Furthermore, implementation of new organizational, reimbursement, and health care delivery models will strongly affect the practice of cardiac electrophysiology. In this brief review, we will provide background and context to the problem of rising health care costs and describe salient reforms and their projected impacts on the field and practice of cardiac electrophysiology.
View details for DOI 10.1007/s10840-012-9773-3
View details for Web of Science ID 000316749200005
View details for PubMedID 23397248
Atrial fibrillation is an abnormal heart rhythm characterized by rapid, disorganized activation (fibrillation) of the left and right atria of the heart, and is responsible for 15% of 700,000 strokes in the United States each year. There are multiple pharmacologic and nonpharmacologic therapies used for stroke prevention in atrial fibrillation, including vitamin K antagonists such as warfarin, antiplatelet agents such as aspirin and clopidogrel, and newer agents such as dabigatran, rivaroxaban and apixaban. Nonpharmacologic therapies involve excluding the left atrial appendage from the systemic circulation by surgical ligation or excision, percutaneous ligation, or endovascular implantation of a left atrial occlusion device. Because atrial fibrillation-related stroke is preventable, a comparison of the value of these interventions by cost-effectiveness analysis (CEA) could inform clinical and health policy recommendations. In this article, we review the principles of CEA and identify 11 articles that examine CEA of stroke prophylaxis strategies in atrial fibrillation. Although most studies evaluate aspirin and warfarin across a variety of atrial fibrillation stroke risk profiles, we also review new literature on new pharmacologic therapies such as direct thrombin inhibitors and discuss the potential value of device-based therapies.
View details for DOI 10.2459/JCM.0b013e32834f23cf
View details for Web of Science ID 000299652200002
View details for PubMedID 22193838