Medical treatment of patients with atrial fibrillation aged over 80 years in daily clinical practice: influence of age and CHADS(2) score

Incidence and Determinants of Traumatic Intracranial Bleeding Among Older Veterans Receiving Warfarin for Atrial Fibrillation

IMPORTANCE

Traumatic intracranial bleeding, which is most commonly attributable to falls, is a common concern among health care professionals, who are hesitant to prescribe oral anticoagulants to older adults with atrial fibrillation.

OBJECTIVE

To describe the incidence of and risk factors for traumatic intracranial bleeding in a large cohort of older adults who were newly prescribed warfarin sodium.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study at the US Department of Veterans Affairs (VA). Participants included 31 951 veterans with atrial fibrillation 75 years or older who were new referrals to VA anticoagulation clinics (for warfarin therapy) between January 1, 2002, and December 31, 2012. The dates of the core analysis were March 2014 through May 2015, and subsequent ad hoc analyses were performed through December 2015. Patients with comorbid conditions requiring warfarin were excluded.

MAIN OUTCOMES AND MEASURES

The primary outcome was hospitalization for traumatic intracranial bleeding. Secondary outcomes included hospitalization for any intracranial bleeding or ischemic stroke. We used International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify the incidence rates of these outcomes after warfarin initiation using VA administrative data (in-system hospitalizations) and Medicare fee-for-service claims data (out-of-system hospitalizations). Clinical characteristics, laboratory results, and pharmacy data were extracted from the VA electronic medical record. For traumatic intracranial bleeding, Cox proportional hazards regression was used to determine predictors of interest selected a priori based on prior known associations.

RESULTS

The study population comprised 31 951 participants. The mean (SD) patient age was 81.1 (4.1) years, and 98.1% were male. Comorbidities were common, including hypertension (82.5%), coronary artery disease (42.6%), and diabetes mellitus (33.8%). During the study period, the incidence rate of hospitalization for traumatic intracranial bleeding was 4.80 per 1000 person-years. In unadjusted models, significant predictors of traumatic intracranial bleeding included dementia, fall within the past year, anemia, depression, abnormal renal or liver function, anticonvulsant use, labile international normalized ratio, and antihypertensive use. After adjusting for potential confounders, the remaining significant predictors for traumatic intracranial bleeding were dementia (hazard ratio [HR], 1.76; 95% CI, 1.26-2.46), anemia (HR, 1.23; 95% CI, 1.00-1.52), depression (HR, 1.30; 95% CI, 1.05-1.61), anticonvulsant use (HR, 1.35; 95% CI, 1.04-1.75), and labile international normalized ratio (HR, 1.33; 95% CI, 1.04-1.72). The incidence rates of hospitalization for any intracranial bleeding and ischemic stroke were 14.58 and 13.44, respectively, per 1000 person-years.

CONCLUSIONS AND RELEVANCE

Among patients 75 years or older with atrial fibrillation initiating warfarin therapy, the risk factors for traumatic intracranial bleeding are unique from those for ischemic stroke. The high overall rate of intracranial bleeding in our sample supports the need to more systematically evaluate the benefits and harms of warfarin therapy in older adults.

Poor adherence to anticoagulation guidelines in patients with non-valvular atrial fibrillation treated in a tertiary cardiology unit

INTRODUCTION

Atrial fibrillation (AF) is a well-known cause of strokes and all major society guidelines recommend oral anticoagulants (OAC) such as vitamin K antagonists (VKA) for patients with concomitant risk factors to prevent them. However, compliance with these guidelines is historically poor. This study aims to evaluate the adherence to CHADS2 (congestive heart failure, hypertension,age ≥75 years, diabetes mellitus and prior stroke or transient ischaemic attack) guidelines, explore reasons and evaluate outcomes for non-adherence in a tertiary cardiology unit.

MATERIALS AND METHODS

A retrospective study of patients admitted into a tertiary cardiology unit from January to March 2010.

RESULTS

Of 1826 unique cardiac patients screened, 163 (8.9%) of them had non-valvular AF or atrial flutter. Their mean age was 69.8 years and 58.9% were men. Of the 54 patients on warfarin with documented international normalised ratio (INR), only 22 (40.7%) of them had an INR within the therapeutic range (INR less than two in 22 (40.7%) and greater than three in 10 (18.5%)). Of the 119 patients with CHADS2 greater than or equal to two, only 46 (38.7%) were discharged with warfarin. Among the remaining 73 (61.3%) patients, the most common reasons for not prescribing warfarin include history of bleeding (n=24, 32.9%), no reason documented (n=17, 23.3%) and patient preference (n=12, 19.2%). On follow-up, patients on warfarin were found to have better survival outcomes (mean 1522±41 days) as compared with (mean 1255±63 days) in patients not on OAC (p value=0.001).

CONCLUSIONS

Few patients who require anticoagulation receive it in accordance with the guidelines even in a tertiary cardiology unit. There are many impediments to the effective use of VKA for stroke prevention among patients with AF.

Comparison of Atrial Fibrillation in the Young versus That in the Elderly: A Review

The incidence and prevalence of atrial fibrillation (AF) are projected to increase significantly worldwide, imposing a significant burden on healthcare resources. The disease itself is extremely heterogeneous in its epidemiology, pathophysiology, and treatment options based on individual patient characteristics. Whilst ageing is well recognised to be an independent risk factor for the development of AF, this condition also affects the young in whom the condition is frequently symptomatic and troublesome. Traditional thinking suggests that the causal factors and pathogenesis of the condition in the young with structurally normal atria but electrophysiological "triggers" in the form of pulmonary vein ectopics leading to lone AF are in stark contrast to that in the elderly who have AF primarily due to an abnormal substrate consisting of fibrosed and dilated atria acting in concert with the pulmonary vein triggers. However, there can be exceptions to this rule as there is increasing evidence of structural and electrophysiological abnormalities in the atrial substrate in young patients with "lone AF," as well as elderly patients who present with idiopathic AF. These reports seem to be blurring the distinction in the pathophysiology of so-called idiopathic lone AF in the young versus that in the elderly. Moreover with availability of improved and modern investigational and diagnostic techniques, novel causes of AF are being reported thereby seemingly consigning the diagnosis of "lone AF" to a rather mythical existence. We shall also elucidate in this paper the differences seen in the epidemiology, causes, pathogenesis, and clinical features of AF in the young versus that seen in the elderly, thereby requiring clearly defined management strategies to tackle this arrhythmia and its associated consequences.

A practical approach to the management of patients with atrial fibrillation

Atrial fibrillation is the most commonly encountered clinical arrhythmia and continues to grow in incidence. Current management involves highly individualised therapies based on underlying concomitant disease processes and symptoms. Moreover, there are numerous therapeutic permutations involving anticoagulation, rate-limitation and antiarrhythmic strategies. This review serves to update the clinician with a practical approach to each patient population and on current advances in management.