Effect of Frailty and Age on Platelet Aggregation and Response to Aspirin in Older Patients with Atrial Fibrillation: A Pilot Study

Abstract

IntroductionFrailty is associated with changes in inflammation, coagulation, and possibly platelet function. Aspirin is still prescribed for stroke prevention in older patients with atrial fibrillation, although not recommended by current guidelines. In frail older people, it is unclear whether platelet aggregability and response to aspirin are altered. This study aims to investigate the effects of frailty and chronological age on platelet aggregability and on responses to aspirin in older patients with atrial fibrillation.MethodsInpatients with atrial fibrillation aged ≥65 years were recruited from a tertiary referral hospital in Sydney, Australia. Frailty was determined using the Reported Edmonton Frail Scale. Platelet aggregation studies were performed using whole blood impedance aggregometry.ResultsData from 115 participants were analyzed (mean age 85 ± 6 years, 41% female, 52% frail). Spearman correlation coefficients found no significant associations of platelet aggregation with chronological age or with frailty score. Comparison between frail and non-frail groups showed that there was no impact of frailty status on aggregation assays amongst participants who were not taking any antiplatelet drugs. Amongst participants taking aspirin, the frail had higher adjusted arachidonic acid agonist (ASPI) test measures (AU per platelet) than the non-frail (0.11 ± 0.11 vs. 0.05 ± 0.04; p = 0.04), suggesting that in frail participants, platelet aggregation is less responsive to aspirin than in non-frail.ConclusionsWe found no effect of chronological age or frailty status on platelet aggregation amongst older patients with atrial fibrillation in this pilot study. However, frailty could be associated with reduced aspirin responsiveness among older patients with atrial fibrillation.

Frail older adults show a distinct plasma microvesicle profile suggesting a prothrombotic and proinflammatory phenotype

“…Frail older adults present a high prevalence of cardiovascular diseases (CVD) and cardiovascular risk factors. In fact, “frailty status” is an important consideration for clinical outcomes and is a feature of surgery stratification (Chen, 2015; Jha et al, 2016; Matthew & Green, 2015; Nguyen, Morel‐Kopp et al, 2017; Nguyen, Pepperell et al, 2016). The presence of CVD has been linked to negative effects on functional performance, walking, and physical activity, which is part of the detection of frailty, and increases the risk of dependence in the elderly (Fried et al, 2001; Stewart, 2019).…”

“…Frailty produces deleterious effects in different key processes that regulate cardiovascular health such as coagulation, platelet function, oxidation state, and endothelial function (Alonso‐Bouzón et al, 2014; Folsom et al, 2007; Liu et al, 2016; Nguyen et al, 2016). In this context, frailty and its pathophysiological mechanisms could produce a pathological synergism with the effects of aging on the cardiovascular system, increasing the susceptibility to CVD.…”

“…In this context, frailty and its pathophysiological mechanisms could produce a pathological synergism with the effects of aging on the cardiovascular system, increasing the susceptibility to CVD. Frailty has been associated with an increased risk of death from CVD, an increased level of oxidative stress, mitochondrial alterations, endothelial dysfunction, and an increased risk of thrombosis (Alonso‐Bouzón et al, 2014; Ashar et al, 2015; Nguyen et al, 2016; Shih et al, 2015). However, the pathological mechanisms related to the higher risk of thrombosis in frail older adults are still not clear.…”

“…Frailty produces deleterious effects in different key processes that regulate cardiovascular health such as coagulation, platelet function, oxidation state, and endothelial function (Alonso-Bouzón et al, 2014;Folsom et al, 2007;Liu et al, 2016;Nguyen et al, 2016).…”

Association of Frailty With Antiplatelet Response Among Elderly Chinese Patients With Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

“…A similar conclusion about the relationship between frailty and the decreased effectiveness of aspirin has also been reported in another study. 15 Frailty is an independent factor that negatively affects prognosis in elderly patients with CAD. Previous research studies have found that the incidence of ischemic events in frail patients was higher than that in nonfrail patients.…”