Related Experiment Video
Updated: Apr 13, 2026
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
APOLLO I: Anticoagulation control in atrial fibrillation
Luís Pinho-Costa1, Sónia Moreira1, Cristiana Azevedo1
1Unidade de Saúde Familiar de Fânzeres, Agrupamento de Centros de Saúde de Gondomar, Gondomar, Portugal.
Insights
This study found that while median time in therapeutic range (TTR) for anticoagulation in atrial fibrillation patients was close to recommended levels, longer atrial fibrillation and anticoagulation durations only slightly improved TTR. Further research is needed to identify other factors influencing anticoagulation control.
Area of Science:
- Cardiology
- Pharmacology
- Public Health
Background:
- Effective anticoagulation control, measured by time in therapeutic range (TTR), is crucial for the safety and efficacy of thromboprophylaxis in atrial fibrillation (AF).
- Assessing TTR and identifying factors influencing it are essential for optimizing patient outcomes in anticoagulation management.
Purpose of the Study:
- To evaluate the TTR achieved in patients with atrial fibrillation at the Family Health Unit of Fânzeres.
- To investigate the sociodemographic and clinical determinants associated with better anticoagulation control.
Main Methods:
- A case series study involving 106 eligible patients with atrial fibrillation treated with warfarin or acenocoumarol.
- TTR was calculated using the Rosendaal method based on International Normalized Ratio (INR) tests from the preceding six months.
- Statistical analysis included descriptive statistics, Spearman's correlation, and Mann-Whitney U/Kruskal-Wallis tests using SPSS 21.0.
Main Results:
- A median TTR of 65.3% was observed in the study population (n=74).
- A significant positive association was found between TTR and the duration of atrial fibrillation (ρ=0.477, p<0.001) and duration of anticoagulation (ρ=0.5, p<0.001).
- No significant association was found between TTR and age, gender, educational level, or the presence of a caregiver.
Conclusions:
- The median TTR in this unit is comparable to other Southern European regions and approaches the European Society of Cardiology's recommended threshold of 70%.
- The duration of AF and anticoagulation only partially explain the variability in TTR, indicating other factors are at play.
- Future research should explore additional determinants of anticoagulation control and consider comparative studies within family health units that manage anticoagulation internally.
Introduction And Aims:
Anticoagulation control as assessed by time in therapeutic range (TTR) correlates positively with the safety and efficacy of thromboprophylaxis in atrial fibrillation. We set out to assess TTR in our unit and to investigate determinants of better control.
Methods:
This was a case series study of atrial fibrillation patients anticoagulated with warfarin or acenocoumarol at the Family Health Unit of Fânzeres. Sociodemographic and clinical data were collected and TTR was calculated by the Rosendaal method, based on international normalized ratio tests performed in external laboratories in the preceding six months. SPSS 21.0 was used for the statistical analysis, with descriptive statistics, Spearman's correlation, and the Mann-Whitney U and Kruskal-Wallis tests.
Results:
Of the 106 eligible patients, 70% participated in the study. Median TTR was 65.3% (P25=48.3%, P75=86.8%). We found a positive association between this variable and duration of atrial fibrillation (ρ=0.477, p<0.001, r(2)=0.116) and with duration of anticoagulation (ρ=0.5, p<0.001, r(2)=0.087). No association was found with age, gender, educational level or existence of a caregiver (p>0.05).
Conclusions:
Median TTR in our unit is similar to that in southern European countries and close to the good control threshold (70%) proposed by the European Society of Cardiology. The duration of atrial fibrillation and of anticoagulation explains only a small part of the measure's variability. Other determinants of anticoagulation control must be investigated in future studies and comparative studies should be carried out in family health units monitoring anticoagulation on the premises.
Related Concept Videos
01:18Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
01:29Venous Thrombosis III: Interprofessional Care
01:12Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
01:20Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
01:25Aortic Regurgitation III: Medical Management