Frequency and Determinants of Adherence to Oral Anticoagulants in Stroke Patients with Atrial Fibrillation in Clinical Practice

Abstract

Background: Vitamin K antagonists (VKAs) and non-VKA oral anticoagulants (NOACs) are beneficial in patients with stroke and atrial fibrillation (AF). However, little is known about frequency and determinants of adherence to NOACs/VKAs in clinical practice. Methods: This is a single-center explorative study from the Novel Oral Anticoagulants in Stroke Patients (NOACISP)-LONGTERM registry. We included consecutive AF-stroke patients treated with NOACs/VKAs and followed up for 3-24 months. Adherence was assessed at follow-up using structured interviews and quantified as the proportion of prescribed doses taken (PDT). Outcome measures were (i) full adherence, (ii) ≥95% adherence and (iii) ≥80% adherence (i.e., PDT 100/≥95/≥80%). To explore determinants of full adherence, we compared characteristics of fully and non-fully adherent patients. Results: A total of 218 of 251 (86.9%) patients (48% female, mean age 77.9 ± 9.1 years, 78% NOACs; 22% VKAs) were eligible for analysis with a median follow-up of 12 months: fully adherent were 78.4% patients (NOACs 77.1%, VKAs 83.3%, p = 0.35), ≥95% adherent were 95.4% and ≥80% adherent were 97.2%. Fully adherent patients took more pills daily (median (interquartile range) 7 (5-10) vs. 6 (4-8), p = 0.039), had more often previous antithrombotic treatment (70.8 vs. 53.2%, p = 0.023), caregiver-assisted medication administration (54.2 vs. 19.1%, p < 0.001) and functional dependency (32.8 vs. 15%, p = 0.011) than non-fully adherent patients. Conclusions: Full adherence was frequent. Patients naïve to antithrombotics, taking few pills, which they self-administer, were at the highest risk of non-adherence and may benefit most from adherence-enhancing interventions.

Determination of Factors that Impact Adherence to Warfarin in Patients with Stroke

“…There are only a few studies on stroke patients presenting self-report adherence rates. These studies reported varying rates for high adherence (between 50% and 84%) (31,32,33). Our findings should be interpreted carefully because the assessment of adherence with a patient self-report approach may cause bias.…”

Does cognitive impairment impact adherence? A systematic review and meta-analysis of the association between cognitive impairment and medication non-adherence in stroke

“…It may, however, be important to distinguish between degrees of cognitive impairment, as individuals with more severe impairments and dementia may rely on caregivers to administer medications, leading to increased adherence [ 17 , 47 ], while those with mild cognitive impairment managing their own medications may be most at risk of sub-optimal adherence. The association between cognitive impairment and adherence, if it exists, may in fact be U-shaped, with poorer adherence in patients with milder cognitive impairments who self-administer their medications, and better adherence in patients with more severe impairments who receive support with medication taking.…”

Long-Term Anticoagulation in Secondary Ischemic Stroke Prevention: The Prospective Multicenter RESTAIC Registry

“…This should encourage us to look for better strategies to improve secondary stroke prevention, such as ensuring patients' adherence to treatment. The NOACISP-LONGTERM registry showed 78.4% of the patients to be fully adherent with a median follow-up of 12 months, and a recent systematic review showed that up to 30% of the patients with AF are non-adherent to any OAC (22,41). Likewise, a Spanish study suggested that only 41.4% of the patients are treated following the current Spanish recommendations in clinical practice (42).…”

“…Taking into account that stroke patients are at high risk both of ischemic and hemorrhagic strokes, and prevention of both are the main objectives in this specific population, it seems necessary to monitor the effects of OAC in non-selected patients in clinical practice. Several registries have been published in recent years to study the use of the various oral anticoagulant treatments in stroke patients (18)(19)(20)(21)(22)(23)(24)(25)(26), mainly evaluating clinical outcomes such as stroke recurrence, cerebral hemorrhage, or functional outcome. Other published registries were focused on the use of radiological markers such as cerebral microbleeds or white matter hyperintensities in order to stratify the hemorrhagic risk in this specific population (27,28).…”