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Prognostic efficacy of platelet count in patients with nonvalvular atrial fibrillation
Jiesuck Park1, Myung-Jin Cha1, You-Jung Choi1
1Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
Insights
Lower platelet counts (PLT) in atrial fibrillation (AF) patients correlate with reduced stroke risk but increased bleeding events. Combining PLT with existing risk factors improves stroke prediction.
Area of Science:
- Cardiology
- Hematology
- Clinical Research
Background:
- The prognostic value of platelet activity in atrial fibrillation (AF) is not well-established.
- Understanding factors influencing AF outcomes is crucial for patient management.
Purpose of the Study:
- To investigate platelet count (PLT) as a prognostic indicator in patients with nonvalvular AF.
- To assess the predictive capability of PLT for stroke and bleeding events.
Main Methods:
- Analysis of data from 10,978 nonvalvular AF patients from a Korean registry.
- Comparison of stroke and bleeding risks across normal, mild, and moderate to severe thrombocytopenia groups post-propensity score matching.
- Development and evaluation of stroke prediction models with and without PLT integration using AUC.
Main Results:
- Moderate to severe thrombocytopenia was associated with a significantly lower risk of stroke (HR 0.57).
- Platelet count showed a reverse relationship with bleeding risk, with higher risks in thrombocytopenia groups (moderate to severe: HR 2.19; mild: HR 1.43).
- The model incorporating PLT demonstrated improved stroke risk prediction (AUC 0.644) compared to conventional risk factors alone (AUC 0.628).
Conclusions:
- Lower platelet counts in AF patients are linked to decreased stroke risk but elevated bleeding risk.
- Integrating platelet count into existing risk assessment models significantly enhances stroke prediction accuracy in nonvalvular AF.
Background:
The prognostic efficacy of quantitative platelet activity in atrial fibrillation (AF) remains unclear.
Objective:
The purpose of this study was to evaluate the platelet count (PLT) as a prognostic indicator in patients with nonvalvular AF.
Methods:
Data on 10,978 patients with nonvalvular AF were retrieved from a prospective registry of a single medical center in Korea. Cumulative risk for stroke and bleeding events were compared between patients with normal PLT (n = 8322), mild thrombocytopenia (n = 1791), and moderate to severe thrombocytopenia (n = 865) after propensity score matching. Prediction models for stroke were derived by conventional risk factors (model 1) and by combining PLT with model 1 (model 2), and model performance was assessed by area under the receiver operator characteristics curve (AUC).
Results:
During the follow-up period, 7.3%, 7.0%, and 4.5% had stroke and 7.6%, 10.8%, and 17.2% had bleeding events in the normal PLT, mild, and moderate to severe thrombocytopenia groups, respectively. Compared to the normal PLT group, the moderate to severe thrombocytopenia group showed a lower risk of stroke (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.40-0.80; P = .002). A reverse relationship was found between PLT and bleeding risk (moderate to severe thrombocytopenia: HR 2.19; 95% CI 1.77-2.70; P <.001; mild thrombocytopenia: HR 1.43; 95% CI 1.18-1.73; P <.001). Compared to model 1, model 2 showed significant improvement in risk prediction (AUC 0.628 vs 0.644; P <.001).
Conclusion:
A lower PLT was associated with a lower risk of stroke and a higher risk of bleeding events. PLT combined with conventional risk factors showed significant improvement in prediction for stroke.
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