Perceived stress predicts the stability of vitamin K-antagonist treatment of anticoagulant clinic patients

Failure of the Anticoagulant Therapy and Psychological Distress: Still Far From a Bridge

Background: The procoagulant stress response reflects part of a beneficial adaptation of the organism to environmental threats, but a protracted procoagulant state generates a thrombotic risk. Atrial fibrillation (AF) is the most common arrhythmia in the general population. Patients with AF have a higher risk of thromboembolic events and stroke, therefore they are treated with long-term oral anticoagulant (OAC) therapy. The aim of this study is to evaluate if there is any association between psychological distress and clinically unexplained variations of the International Normalized Ratio (INR), that is the index used to monitor both thromboembolic and bleeding risk in the case of patients under OAC therapy.

Methods: Fifty-eight patients (men = 27; women = 31; mean age = 74.98) were recruited. The sample was divided according to the recognition (or not) of the reason why the INR was subtherapeutic (<2) and classified as “Known Reasons” (KR = 32.8%) and “Unknown Reasons” (UR = 67.2%). Psychological assessment included the following dimensions: symptoms of anxiety and depression, perceived stress, emotional regulation strategies, and alexithymia.

Results: Considering Mann–Whitney test results, no significant difference was found in the scores of anxiety, depression, stress, and emotional regulation strategies. With regard to alexithymia, UR patients are characterized by a moderate tendency to an outward-oriented thinking (r = 0.25).

Conclusion: A clear role for the detected psychological factors in determining abnormal INR range in patients under OAC therapy could not be found. Further studies are needed to support our findings, if possible exploring factors other than psychological distress and the related emotion regulation strategies.

Patient knowledge of anticoagulant treatment does not correlate with treatment quality

OBJECTIVES

The objectives of this study were to investigate whether patient knowledge is a predictor of treatment stability in anticoagulant clinic patients and to evaluate the correlation between the patients' subjective assessment of own knowledge and their score on a validated knowledge assessment instrument.

STUDY DESIGN

This is a prospective study where international normalized ratio (INR) stability was followed up 6 months after knowledge assessment.

METHODS

We analyzed data of 42 consecutive patients new to vitamin-K antagonist (VKA) treatment and 64 experienced patients from an anticoagulant clinic offering patient education. The patients filled out a VKA knowledge assessment questionnaire with 24 items under standardized conditions, and simultaneously, they were asked about their subjective knowledge. Subsequently, time in range of INR (TIR) was collected for each patient.

RESULTS

Out of the 106 patients, 52 had 18 or more correct answers (>75%), defined as a 'satisfactory level' of objective knowledge. The average TIR was 73%, and treatment stability was significantly higher in experienced patients than new patients. We found no correlation between objective knowledge and TIR (Spearman rho = -0.03, P = 0.78). Most patients (77%) reported a high subjective knowledge of VKA, but no correlation was found between objective and subjective knowledge (Spearman rho = 0.129, P = 0.19).

CONCLUSION

We observed that many patients had a low level of knowledge of VKA, despite high treatment stability and patient education. The patient's own assessment of knowledge was not found to predict objective knowledge, which could have implications for selection of patients for self-test or self-management of treatment.

Vitamin K antagonists in heart disease: current status and perspectives (Section III). Position paper of the ESC Working Group on Thrombosis--Task Force on Anticoagulants in Heart Disease

Oral anticoagulants are a mainstay of cardiovascular therapy, and for over 60 years vitamin K antagonists (VKAs) were the only available agents for long-term use. VKAs interfere with the cyclic inter-conversion of vitamin K and its 2,3 epoxide, thus inhibiting γ-carboxylation of glutamate residues at the amino-termini of vitamin K-dependent proteins, including the coagulation factors (F) II (prothrombin), VII, IX and X, as well as of the anticoagulant proteins C, S and Z. The overall effect of such interference is a dose-dependent anticoagulant effect, which has been therapeutically exploited in heart disease since the early 1950s. In this position paper, we review the mechanisms of action, pharmacological properties and side effects of VKAs, which are used in the management of cardiovascular diseases, including coronary heart disease (where their use is limited), stroke prevention in atrial fibrillation, heart valves and/or chronic heart failure. Using an evidence-based approach, we describe the results of completed clinical trials, highlight areas of uncertainty, and recommend therapeutic options for specific disorders. Although VKAs are being increasingly replaced in most patients with non-valvular atrial fibrillation by the new oral anticoagulants, which target either thrombin or FXa, the VKAs remain the agents of choice for patients with atrial fibrillation in the setting of rheumatic valvular disease and for those with mechanical heart valves.