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Updated: May 8, 2026
Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Relationship between platelet indices and international normalized ratio in patients with non-valvular atrial
Osman Ziya Arık1, Buğra Ozkan, Rasim Kutlu
1Department of Cardiology, Gümüşhane State Hospital , Gümüşhane , Turkey .
Insights
Platelet indices like MPV, PDW, and PCT are elevated in atrial fibrillation patients with ineffective warfarin treatment. These markers can help monitor warfarin effectiveness in preventing thromboembolic events.
Area of Science:
- Cardiology
- Hematology
Background:
- Atrial fibrillation (AF) is a common arrhythmia linked to adverse outcomes and thromboembolic risks.
- Warfarin is a primary oral anticoagulant for AF stroke prevention.
- Monitoring warfarin's effectiveness is crucial for patient outcomes.
Purpose of the Study:
- To investigate platelet indices (MPV, PDW, PCT) in non-valvular AF patients on warfarin.
- To assess the relationship between these indices and warfarin's International Normalized Ratio (INR) control.
- To identify platelet indices as predictors of warfarin treatment effectiveness.
Main Methods:
- A study involving 250 non-valvular AF patients and 123 controls.
- Patients were grouped by INR: effective (2.0-3.0) and ineffective (<2.0).
- Complete blood counts, INR, and echocardiography were analyzed.
Main Results:
- Mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) were significantly higher in AF patients with ineffective INR.
- These indices showed positive correlations with each other and inverse correlation with INR.
- MPV, PDW, and PCT were identified as independent predictors of ineffective INR.
Conclusions:
- Elevated MPV, PDW, and PCT indicate ineffective warfarin treatment in non-valvular AF.
- Warfarin therapy, when achieving therapeutic INR, is associated with lower platelet indices.
- These platelet indices may serve as valuable tools for monitoring warfarin efficacy.
Abstract:
Atrial fibrillation (AF) is the most common sustained arrhythmia and associated with adverse outcomes and increased risk for thromboembolic events. Warfarin is still the most extensively prescribed oral anticoagulant in AF to prevent ischemic complications. We aimed to determine the differences at platelet indices with warfarin usage layered by International Normalized Ratio (INR). A total of 250 patients with permanent non-valvular AF (mean age 70.2 ± 9.1; 153 female) were divided into two groups. Group 1 included 125 patients whose INR is between 2.0 and 3.0 (called as "effective") and Group 2 included 125 patients whose INR is <2.0 (called as "ineffective"). Also 123 age- and sex-matched individuals in sinus rhythm enrolled as control group (Group 3). After physical and echocardiographic examination, complete blood counts and INR were studied. There was no statistically significant difference in age, sex, co-morbidities and medications, also hemoglobin, white blood cell and platelet counts among the groups. The CHA2DS2-VASc scores were similar between Groups 1 and 2. The mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) were significantly higher in Group 2 than Groups 1 and 3 and similar between Groups 1 and 3. MPV was positively correlated with PDW and PCT and also inversely correlated with INR value and platelet count. On multivariate logistic regression analysis, MPV, PDW and PCT were independent predictors of ineffectiveness of INR. The results of this study showed that MPV, PDW and PCT are increased in patients with non-valvular AF without effective warfarin treatment. Warfarin usage adjusted by INR is associated with lower values of these platelet indices, even lower as the values of subjects in sinus rhythm. MPV, PDW and PCT are independent predictors of INR ineffectiveness and seem to be useful parameters for monitoring the effectiveness of warfarin treatment.
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