Patterns and predictors of discontinuation of rhythm-control drug therapy in patients with newly diagnosed atrial fibrillation

Patterns and predictors of osteoporosis medication discontinuation and switching among Medicare beneficiaries

BACKGROUND

Low adherence to bisphosphonate therapy is associated with increased fracture risk. Factors associated with discontinuation of osteoporosis medications have not been studied in-depth. This study assessed medication discontinuation and switching patterns among Medicare beneficiaries who were new users of bisphosphonates and evaluated factors possibly associated with discontinuation.

METHODS

We identified patients initiating bisphosphonate treatment using a 5% random sample of Medicare beneficiaries with at least 24 months of traditional fee-for-service and part D drug coverage from 2006 through 2009. We classified medication status at the end of follow-up as: continued original bisphosphonate, discontinued without switching or restarting, restarted the same drug after a treatment gap (≥ 90 days), or switched to another anti-osteoporosis medication. We conducted logistic regression analyses to identify baseline characteristics associated with discontinuation and a case-crossover analysis to identify factors that precipitate discontinuation.

RESULTS

Of 21,452 new users followed respectively for 12 months, 44% continued their original therapy, 36% discontinued without switching or restarting, 8% restarted the same drug after a gap greater than 90 days, and 11% switched to another anti-osteoporosis medication. Factors assessed during the 12-month period before initiation were weakly associated with discontinuation. Several Factors measured during follow-up were associated with discontinuation, including more physician visits, hospitalization, having a dual-energy X-ray absorptiometry test, higher Charlson comorbidity index scores, higher out-of-pocket drug payments, and upper gastrointestinal problems. Patterns were similar for 4,738 new users followed for 30 months.

CONCLUSIONS

Among new bisphosphonates users, switching within and across drug classes and extended treatment gaps are common. Robust definitions and time-varying considerations should be considered to characterize medication discontinuation more accurately.

Impact of dronedarone treatment on healthcare resource utilization in patients with atrial fibrillation/flutter

BACKGROUND

The ATHENA (A Placebo-Controlled, Double-Blind, Parallel Arm Trial to Assess the Efficacy of Dronedarone 400 mg bid for the Prevention of Cardiovascular Hospitalization or Death from Any Cause in Patients with Atrial Fibrillation/Atrial Flutter) trial demonstrated a significant reduction (26%) in the rate of first cardiovascular (CV) hospitalization in dronedarone-treated patients with paroxysmal or persistent atrial fibrillation/flutter (AF/AFL). ATHENA was the first trial to demonstrate a CV outcomes benefit, specifically reduced CV hospitalizations, with an antiarrhythmic drug. The objective of this study was to assess the impact of dronedarone treatment on healthcare resource utilization among real-world patients with AF/AFL in United States clinical practice.

METHODS

This retrospective cohort study used claims data from the MarketScan® databases (Truven Health, Durham, NC, USA) to identify patients with ≥2 concurrent de novo pharmacy claims for dronedarone (≥180 days' total supply) between June 2009 and March 2011, and with an AF/AFL diagnosis and no heart failure-related hospitalization during the 12 months preceding the initial (index) dronedarone claim. Annualized inpatient and outpatient resource utilization were compared between the pre-index (baseline) and post-index (follow-up) periods.

RESULTS

In total, 5,656 AF/AFL patients were prescribed dronedarone for ≥6 months and were followed for mean (standard deviation) 11.9 (4.7) months. Reductions in mean numbers of annualized all-cause, CV- and AF-related hospitalizations (~40-45%), and emergency department visits (~30-45%) were realized. These benefits were offset by increases in office visits (~10-30%) and AF-related prescription claims (74%) after dronedarone initiation. The sub-cohort of patients switching to dronedarone from Prior Rhythm-Control therapy (n=2,080) showed similar reductions in hospital and emergency department events.

CONCLUSIONS

This study suggests that dronedarone use in real-world practice, as in the ATHENA trial, results in substantial reductions in hospital admissions, both in first-line and second-line antiarrhythmic treatment settings.

Hospital readmissions in US atrial fibrillation patients: occurrence and costs

The aim of the study was to examine the temporal readmission pattern, proportion of readmissions attributed to cardiovascular (CV) causes, and the duration and costs associated with readmission in hospitalized patients with atrial fibrillation/flutter (AF/AFL). This retrospective cohort study used medical claims data from the PharMetrics Patient-Centric database (IMS Health, Watertown, MA) between January 2007 and March 2008. The patients hospitalized with a primary diagnosis of AF/AFL and with ≥12 months' continuous medical and prescription coverage before and after the initial AF/AFL hospitalization were identified from this database. The main outcome measures were rehospitalization patterns [all-cause, all CV-related (including AF/AFL), and AF/AFL-related only], which were assessed over the 12-month post-index period, and costs of initial and subsequent AF/AFL-related hospitalizations that were compared. The study included 8035 patients with AF/AFL (mean age 66.1 years; 57.6% males). Rehospitalization was common (37.9% of patients), with the most frequent causes being CV (34.1%) and, specifically, AF/AFL-related (26.8%). The highest proportion of rehospitalizations occurred within 30 days of the initial hospitalization (25%). Readmissions with a primary diagnosis of AF/AFL (n = 1238) were significantly longer (4.0 vs. 3.6 days; P = 0.0229) and more costly (US$8966 vs. US$7080; P < 0.0001) than the index hospitalization. Hospitalized AF/AFL patients experience high rates of CV- and AF/AFL-related readmissions, particularly within the first 30 days. Subsequent AF/AFL-related readmissions incur higher costs than the initial AF/AFL hospitalization. Treatments resulting in reduced readmissions would improve patient outcomes, quality of life and the cost burden associated with AF/AFL.

Cost effectiveness of antiarrhythmic medications in patients suffering from atrial fibrillation

Atrial fibrillation (AF), a supraventricular tachycardia disorder, is the most common sustained cardiac arrhythmia affecting 1-2 % of the general population. Prevalence is highly related to age, with every fourth individual older than 40 years old developing AF during his lifetime. Due to an aging population, the prevalence of AF is estimated to at least double within the next 50 years. This article presents AF-related cost-of-illness studies and reviews 19 cost-effectiveness studies and six cost studies published roughly over the past decade, which have compared different antiarrhythmic medications for AF. A systematic literature search for studies published between June 2000 and December 2011 was conducted in PubMed using the combination of keywords ((atrial fibrillation OR atrial flutter) AND cost). Current cost-effectiveness analyses of dronedarone and the pill-in-the-pocket strategy are subject to substantial uncertainties with regard to clinical benefit. Comparing rate control with rhythm control, a cost-effectiveness advantage for rate control was shown in several but not all studies. Within antiarrhythmic drug treatments, magnesium added onto ibutilide was shown to be more cost effective than ibutilide alone. Comparing chemical and electrical cardioversion, the latter was recommended as more cost effective from the healthcare system perspective in all reviewed studies but one. Catheter ablation appeared more cost effective than antiarrhythmic drugs in the medium to long run after 3.2-63.9 years. Admissions to hospital, inpatient care and interventional procedures as well as mortality benefit are key drivers for the cost effectiveness of AF medications. No clear cost-effectiveness advantage emerged for one specific antiarrhythmic drug from the studies that compared antiarrhythmic agents. Rate control as well as catheter ablation appear more cost effective than rhythm control in the treatment of AF. Rate control treatment also seems more cost effective than electrical cardioversion in AF patients.

Do the benefits of anti-arrhythmic drugs outweigh the associated risks? A tale of treatment goals in atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac rhythm disorder and places a substantial burden on the US healthcare system. Unfortunately, there is no consensus as to whether patients should be treated with a primary rate- or rhythm-control strategy. The use of anti-arrhythmic drugs in the treatment of AF is discussed in the broader context of AF disease-management strategies with a focus on rhythm control. Outside of rhythm/ECG, AF treatment targets and cardiovascular outcomes are highlighted.

Costs and clinical consequences of suboptimal atrial fibrillation management

Atrial fibrillation (AF) places a considerable burden on the US health care system, society, and individual patients due to its associated morbidity, mortality, and reduced health-related quality of life. AF increases the risk of stroke, which often results in lengthy hospital stays, increased disability, and long-term care, all of which impact medical costs. An expected increase in the prevalence of AF and incidence of AF-related stroke underscores the need for optimal management of this disorder. Although AF treatment strategies have been proven effective in clinical trials, data show that patients still receive suboptimal treatment. Adherence to AF treatment guidelines will help to optimize treatment and reduce costs due to AF-associated events; new treatments for AF show promise for future reductions in disease and cost burden due to improved tolerability profiles. Additional research is necessary to compare treatment costs and outcomes of new versus existing agents; an immediate effort to optimize treatment based on existing evidence and guidelines is critical to reducing the burden of AF.

Impact of comorbidity on medication use in elderly patients with cardiovascular diseases: the OCTOCARDIO study

BACKGROUND

Recommended medications are under-prescribed in elderly patients with atrial fibrillation (AF), coronary artery disease (CAD), and congestive heart failure (CHF). The relationship between under-prescribing and comorbidity is unclear.

DESIGN

Single-day observational study.

METHODS

Analysis of medications taken by patients aged 80 years or over at the time of their admission to cardiology units of 32 French hospitals. Comorbidity was measured using the Charlson comorbidity index (CCI).

RESULTS

The study included 510 patients (57% men, mean age 85 years). History of AF, CHF, and CAD was present in 213 (42%), 199 (39%), and 187 (37%) patients, respectively. CCI was 0 in 110 (22%), 1-2 in 215 (42%), and ≥3 in 185 (36%) patients. Vitamin K antagonists (VKA) were prescribed to 105 (49%) and aspirin to 86 (40%) patients with AF. CCI did not influence VKA prescription but influenced aspirin use, with lower prescription rates in patients with CCI 1-2 than CCI 0 or CCI ≥3 (p = 0.02). In CHF, angiotensin-converting enzyme inhibitors (ACEI) and β-blockers were prescribed to 80 (40%) and 96 (48%) patients, respectively. Rates of prescription of ACEI, β-blockers, statins, and aspirin in patients with CAD were 43%, 56%, 56%, and 66%, respectively. CCI level did not influence any medication use in CHF and CAD.

CONCLUSION

Even in the absence of comorbidity, elderly patients with major cardiovascular diseases are denied from indicated medical treatments probably because of their age alone. Implementing measures to enhance awareness of treatment benefits and promote appropriate prescribing is necessary.

One-year treatment persistence and potential adverse events among patients with atrial fibrillation treated with amiodarone or sotalol: a retrospective claims database analysis

BACKGROUND

The risk-benefit profile of antiarrhythmic drugs (AADs) affects the choice of pharmacotherapy for maintenance of sinus rhythm. Adverse events (AEs) associated with AADs may influence patient compliance and compromise the management of atrial fibrillation (AF). There are limited data on the incidence of AEs or persistence with AADs outside the clinical trial environment.

OBJECTIVE

This study provides treatment persistence and AE data for patients with AF receiving treatment with amiodarone or sotalol, 2 of the most widely used AADs in the United States.

METHODS

In this retrospective cohort study, patients satisfying the following criteria were identified from the US MarketScan claims databases: (1) age ≥18 years with a pharmacy claim for oral amiodarone or sotalol between 2004 and 2007; (2) ≥1 inpatient/outpatient medical claim with an AF diagnosis <90 days before the earliest (index) pharmacy claim; and (3) ≥12 months' continuous enrollment before and after the index pharmacy claim. Prespecified AE rates were compared between treatment cohorts during active treatment.

RESULTS

Among 77,093 AF patients with ≥1 claim for amiodarone or sotalol, 3459 met all inclusion criteria (mean age, 70.8 years; 61.6% male; mean Charlson Comorbidity Index [CCI], 1.58), of whom 2392 received amiodarone (mean age, 72.2 years; 62.5% male; mean CCI, 1.8) and 1067 received sotalol (mean age, 67.5 years; 59.7% male; mean CCI, 1.1). Persistence was higher among the sotalol cohort than the amiodarone cohort (53.2% vs 30.6% at 12 months; P < 0.001). Postindex versus preindex comparisons revealed increases in cardiovascular AE rates in both cohorts. Intercohort comparisons showed higher rates of cardiovascular AEs (594 vs 339 patients/1000 patient-years; P < 0.001) and pulmonary AEs (128 vs 61 patients/1000 patient-years; P < 0.001) during active amiodarone treatment.

CONCLUSIONS

Among the population analyzed, patients with AF receiving amiodarone versus sotalol therapy had differing clinical characteristics. Patients experienced frequent AEs (particularly cardiovascular events) with amiodarone and sotalol, and many discontinued treatment during the first year.

A review of the cost of atrial fibrillation

OBJECTIVES

To systematically review and synthesize the literature on the costs of atrial fibrillation (AF) with attention to study design and costing methods, geography, and intervention approaches.

METHODS

A systematic search for previously published studies reporting the costs for AF patients was conducted. Data were analyzed in three steps: first by evaluating overall system costs; second by evaluating the relative contribution of specific cost components; and third by examining variations across study designs, across primary treatment approach, and by geography. Finally, a specific review of the treatment costs associated with anticoagulation treatment was examined given the clinical importance and attention given to these costs in the literature.

RESULTS

The literature search resulted in 115 articles. On review of the abstracts or full text of these articles, 21 articles met all study criteria and reported on health system AF-related direct costs. A further six articles focused exclusively on anticoagulation costs for patients with AF. The overall average annual system cost across 27 estimates obtained from the literature was $5450 (SD = $3624) in 2010 Canadian dollars and ranged from a low of $1,632 to a high of $21,099. About one-third of these costs could be attributed to anticoagulation management. The largest cost component was acute care, followed by outpatient and physician and then medication-related costs.

CONCLUSION

AF-related medical costs are high, reflecting resource-intensive and long-term treatments including anticoagulation treatment. These costs, accompanied with increasing prevalence, justify increased attention to the management of patients with AF. Future studies of AF cost should ensure a broad assessment of the incremental direct medical and societal cost associated with this diagnosis.

Update on the clinical management of atrial fibrillation: guidelines and beyond

In clinical practice, atrial fibrillation (AF) is the most commonly encountered arrhythmia. With the aging of the US population, the number of patients with AF that physicians encounter will increase. Atrial fibrillation management involves a combination of rate- and rhythm-control strategies with thromboprophylaxis, a complicated endeavor given side effect profiles of treatments, patient comorbidities, and anticoagulation treatment requirements. Early treatment discontinuation and poor compliance with anticoagulation treatment are frequent and result in increased mortality, a 5-fold increased risk of ischemic stroke, decreased health-related quality of life, and decreased exercise capacity. In 2006, the American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) provided guidelines for the management of patients with AF. Recently, the ACC Foundation, AHA, and Heart Rhythm Society released updates to these guidelines (January and February 2011). This article aims to assist physicians in improving the management of patients with AF by focusing on the main components of therapy as reflected in the guidelines, and by providing an update on new US Food and Drug Administration-approved treatments.

Temporal pattern and costs of rehospitalization in atrial fibrillation/atrial flutter patients with one or more additional risk factors

OBJECTIVES

The ATHENA study showed that use of dronedarone reduced rates of first cardiovascular (CV) hospitalization in atrial fibrillation/flutter (AF/AFL) patients. AF is associated with high costs to payers, which are driven by high rates of hospitalization. This retrospective cohort study examined readmission patterns and costs to US payers in real-world AF/AFL patients with ≥1 additional risk factor (ARF).

METHODS

Patients hospitalized (January 2005-March 2008) with AF/AFL as primary diagnosis and having ≥1 year of health coverage, before and after their first (index) admission, were identified in the PharMetrics Patient-Centric database. As in the ATHENA study, patients had to be ≥75 years of age or ≥70 years, with ≥1 ARF. Rehospitalization patterns (all-cause, all CV-related [including AF/AFL] and AF/AFL-related alone) were examined over 1 year post-index, and costs of index vs later AF/AFL admissions compared.

RESULTS

The study included 3498 patients (mean 80 [SD 7.6] years; 42.4% men). Over 1 year, 1389 patients (39.7%) were rehospitalized for any cause (mean 1.7 [SD 1.3] events/patient), with 1223 patients (35.0%) undergoing CV-related (mean 1.6 [SD 1.0] events/patient) and 935 (26.7%) undergoing AF-related rehospitalization (mean 1.4 [SD 0.8] events/patient). Common causes of CV-related readmissions (primary diagnosis) were AF/AFL (47.5%), congestive heart failure (CHF) (9.9%), coronary artery disease (7.4%), and stroke/transient ischemic attack (6.2%). Readmission rates at 3 months were 16.2% (all-cause), 14.3% (all CV-related including AF/AFL), and 10.5% (AF/AFL-related alone). AF/AFL readmissions (primary diagnosis) were longer than initial hospitalizations (mean total 6.9 [SD 12.9] vs 4.3 [SD 5.1] days, p < 0.0001) and more costly (median $1819 [25th percentile $1066, 75th percentile $5623] vs $1707 [25th percentile $1102, 75th percentile $4749]).

LIMITATIONS

This study excluded patients with pre-existing CHF, did not require electrocardiogram confirmation of AF/AFL diagnosis, and did not distinguish between paroxysmal, persistent, and permanent AF.

CONCLUSIONS

AF/AFL patients with ≥1 ARF have high readmission rates. AF/AFL-related readmissions incur higher costs than the initial AF/AFL admissions.

The management of patients with atrial fibrillation and dronedarone's place in therapy

The pharmacologic management of atrial fibrillation (AF) includes rate and rhythm control strategies. Antiarrhythmic agents (eg, amiodarone, flecainide, and propafenone) are limited by serious toxicities (including proarrhythmic effects and pulmonary toxicity), which may lead to a reduced net clinical efficacy of rhythm control strategies. Dronedarone, a new antiarrhythmic agent, is effective in the maintenance of sinus rhythm. Dronedarone has also been shown to reduce ventricular rate and the incidence of hospitalization due to cardiovascular events. Dronedarone is recommended by the 2011 American College of Cardiology Foundation/American Heart Association/Heart Rhythm Society guidelines update for the management of AF patients with no or minimal heart disease, coronary artery disease, and hypertension with no left ventricular hypertrophy. Dronedarone is contraindicated in patients with New York Heart Association (NYHA) class IV heart failure or NYHA class II-III heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic.

Incremental cost burden to US healthcare payers of atrial fibrillation/atrial flutter patients with additional risk factors

INTRODUCTION

Atrial fibrillation (AF) and atrial flutter (AFL) patients often have cardiovascular (CV) comorbidities, and have an increased risk of hospitalization and death. Little is known about the real-world cost burden of AF/AFL patients with additional risk factors (ARF). We evaluated the medical resource use and cost burden of AF/AFL patients with ≥1 ARF (other than heart failure [HF]), in comparison with non-AF/AFL controls.

METHODS

This retrospective cohort study included patients from the MarketScan Medicare database who had ≥1 inpatient or ≥2 outpatient AF/AFL claims. Patients were (1) ≥75 years of age or (2) 70-74 years of age with ≥1 ARF (hypertension, diabetes, systemic embolism, or stroke/transient ischemic attack), but without HF. The AF/AFL patients were matched on age, gender, region, and enrollment status with non-AF/AFL patients. Hospital resource use and costs over the 12-month post-index period were compared across cohorts. The impacts of comorbidity were seen by subcategorizing hospitalization as all-cause, CV-related, and AF/AFL-related.

RESULTS

AF/AFL patients with ≥1 ARF had a higher prevalence of comorbidity than non-AF/AFL patients (n=58,555/cohort). Hospitalizations (all-causality) were more than three times more frequent and of longer duration in AF/AFL patients with ≥1 ARF than in non-AF/AFL controls (mean [SD]: 0.72 [0.87] vs. 0.21 [0.51] hospitalizations per patient per year and 3.85 [9.30] and 1.03 [4.53] days, respectively; both P<0.0001). Overall mean (SD) costs over the 12-month post-index period were higher in AF/AFL patients with ≥1 ARF versus the non-AF/AFL control patients for inpatient ($9613 [25,407] vs. $2625 [11,597]; P<0.0001; incremental cost $6988), outpatient ($9447 [15,062] vs. $4906 [11,715]; P<0.0001; incremental cost $4541), and prescription drug costs ($3430 [3637] vs. $2618 [3374]; P<0.0001; incremental cost $812).

CONCLUSION

AF/AFL patients with ≥1 ARF had significantly greater levels of comorbidity, hospitalizations, prescription, and outpatient claims than non-AF/AFL patients. The incremental costs of AF/AFL patients with ≥1 ARF are largely due to higher CV-related inpatient costs.