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Published on: February 28, 2012
Anticoagulation Control in Older Atrial Fibrillation Patients Receiving Vitamin K Antagonist Therapy for Stroke
Hanis Zulkifly1,2, Gregory Y H Lip1,3,4, Deirdre A Lane1,3,4
1University of Birmingham Institute of Cardiovascular Sciences, Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK.
Insights
Older atrial fibrillation patients (≥80 years) achieve similar anticoagulation control (TTR) as younger patients, but face a higher bleeding risk. Improving monitoring is crucial for this age group.
Area of Science:
- Cardiology and Geriatric Medicine
- Pharmacology and Therapeutics
Background:
- Optimal anticoagulation control with vitamin K antagonists (VKAs) for atrial fibrillation (AF) patients requires maintaining the International Normalized Ratio (INR) between 2.0-3.0.
- Concerns exist regarding lower anticoagulation control and its impact on treatment initiation and outcomes in older AF patients.
Purpose of the Study:
- To assess the quality of INR control, adverse clinical outcomes, and bleeding risk factors in elderly AF patients aged 80 years and above.
- To compare anticoagulation control and clinical outcomes between patients aged ≥80 years and those younger than 80 years.
Main Methods:
- Retrospective analysis of 205 AF patients aged ≥80 years, evaluating anticoagulation control using Time in Therapeutic Range (TTR) and Percentage of INRs in Range (PINRR).
- Comparison of TTR, PINRR, monitoring intensity, and follow-up duration between patients ≥80 years and <80 years.
- Assessment of major adverse clinical events and bleeding risk using Cox regression analysis.
Main Results:
- Patients aged ≥80 years demonstrated similar mean TTR and PINRR compared to younger patients, despite reduced INR monitoring intensity and shorter follow-up.
- 44% of patients in both age groups achieved good anticoagulation control (TTR and PINRR ≥70%).
- Age ≥80 years was independently associated with an increased risk of bleeding (HR 1.90; p=0.047), with no significant difference in major adverse clinical events or all-cause mortality.
Conclusions:
- Suboptimal anticoagulation control (TTR and PINRR <70%) was prevalent across all patients.
- While older AF patients (≥80 years) face a higher bleeding risk, they do not experience increased thromboembolic events or mortality compared to younger counterparts.
- Enhancing anticoagulation monitoring and achieving TTR ≥70% are critical clinical priorities to mitigate bleeding complications, especially in elderly patients.
Introduction:
Efficacy and safety of vitamin K antagonists (VKAs) among atrial fibrillation (AF) patients are enhanced when the International Normalised Ratio (INR) is 2.0-3.0. Anticoagulation control among older patients is perceived to be lower and contributes to poorer initiation and uptake.
Objective:
To examine the quality of INR control, adverse clinical outcomes, and factors associated with bleeding in older AF patients (≥80 years).
Methods:
Anticoagulation control assessed by time in therapeutic range (TTR) (Rosendaal method) and percentage INRs in range (PINRR). Among the 205 patients aged ≥80 years, 58.5% were female, with mean (SD) CHA2DS2-VASc 4.4 (1.3) and HAS-BLED 1.8 (0.8) scores.
Results:
Mean (SD) TTR and PINRR were similar for those aged ≥80 vs. <80 years (66.7 (13.8) vs. 66.7 (13.1)) despite significantly lower INR monitoring intensity (51.2 (22.7) vs. 60.7 (25.8)) and shorter follow-up (4.4 (2.6-6.2) vs. 5.7 years (3.3-7.1)) in those ≥80 years of age. Good anticoagulation control (TTR and PINRR ≥70%) of 44% was seen in both age groups. No significant differences in composite major adverse clinical events were evident for those aged ≥80 vs. <80 years (p = 0.55). Cox regression analysis confirmed that age ≥80 years was associated with higher risk of bleeding (HR 1.90 (1.01-3.56); p = 0.047).
Conclusions:
Suboptimal (TTR and PINRR <70%) anticoagulation control was evident in all patients. Risk of bleeding increased, but there was no difference in thromboembolic events and all-cause mortality in those aged ≥80 years. Improving TTR to ≥70% and enhancing anticoagulation monitoring of VKA use remain a clinical priority to prevent bleeding complications, particularly among those aged 80 years and above.
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