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This section looks at the epidemiology of age in patients with AF and examines how a patient’s age affects prognosis and treatment
Advancing age is a prominent risk factor for atrial fibrillation (AF).1 Furthermore, amongst patients with AF, age increases the risk of stroke by 1.5-fold per decade.2 This association is typically related to age-related complications, such as frailty, renal impairment, heart failure, hypertension and cognitive impairment, which worsen the prognosis of patients with AF.3,4 Older patients may be living independently, and a stroke event is likely to change the lives of these patients dramatically. Therefore, older people represent a large group of high-risk patients living with AF that we need to protect, with the global burden only expected to increase.1
Older patients with AF are at increased risk of stroke2
Because of their elevated risk of stroke, older patients with AF stand to benefit greatly from anticoagulation, and evidence suggests that these benefits outweigh the risk of bleeding. Despite this, they are among the least likely to receive anticoagulation.2,3,5
Strokes related to AF are largely preventable with appropriate treatment,6 therefore it’s of utmost importance to protect the independence and future of older people living with AF.
Subanalyses of patients with AF aged ≥75 years in the phase III clinical studies of non-vitamin K antagonist oral anticoagulants (NOACs; rivaroxaban, apixaban, dabigatran or edoxaban) demonstrated that the efficacy and safety profiles of anticoagulation did not differ with age.7-10 A meta-analysis of these clinical studies further confirmed these findings.11
The ROCKET AF study of rivaroxaban included the highest percentage of older patients (aged ≥75 years) out of all the phase III NOAC studies. These older patients also had the highest average CHADS2 score and the highest percentage of complications including congestive heart failure, diabetes and prior stroke or transient ischaemic attack.7-10
The results of ROCKET AF were consistent with real-world observations, such as those in the phase IV XANTUS study, in which rivaroxaban was associated with low rates of stroke and bleeding events in a broad population of patients with AF, and included 37% of patients aged >75 years.12
Further real-world evidence comes from the prospective, observational SAFIR cohort study of 995 patients aged ≥80 years with AF, where major bleeding events were significantly lower with rivaroxaban compared with vitamin K antagonists (VKAs) at 1 year.13 In addition, according to one-year clinical outcomes pooled from large European registries PREFER in AF and PREFER in AF PROLONGATION, NOAC use was associated with a better net clinical benefit compared with VKAs in 3,825 patients aged ≥75 years with AF, primarily because of the lower rates of major bleeding events.14
It is also reassuring that the retrospective analyses involving frail patients with AF who are typically older, confirmed that rivaroxaban reduced the risk of stroke at 2 years compared with warfarin without altering the risk of major bleeding events.15
These studies suggest that NOACs reduce the risk of stroke compared with VKAs regardless of age, with comparable or lower rates of major bleeding events. Because the evidence highlights that age is not a reason to withhold anticoagulation, more could be done to protect the older population with AF.
European and American guidelines recommend anticoagulation for men with a CHA2DS3-VASc score ≥2 and women with a score ≥3; oral anticoagulation should be considered in men with a score ≥1 and in women with a score ≥2. In practice, because the female gender accounts for a score of 1 each, in the presence of an additional risk factor, all patients should be at least considered for oral anticoagulation.5,16
Age is one of the risk factors considered in this score, with an age ≥75 years accounting for a score of 2 and an age >65 years for a score of 1. Therefore, anticoagulation is recommended in patients aged ≥75 years even if they don’t have other risk factors, and in patients aged >65 years with at least one other risk factor. In patients aged >65 years with no additional risk factors, anticoagulation should still be considered.5,16
ESC and ACC/AHA/HRS guidelines for the management of AF recommend NOACs over VKAs for the treatment of NOAC-eligible patients.5,16 An important consideration for the use of NOACs is dose reductions that might apply to older patients. Apixaban or dabigatran have specific label guidance for recommended dose reductions in patients aged ≥80 years.17,18 Furthermore, because age is associated with declines in renal function, guidance for reduced NOAC doses in this population may need to be considered.17-21 More information on dose reductions in patients with AF and renal impairment can be found here .
See knowledge base section on ‘Patients with Renal Impairment’