[Frequency of use of oral vitamin K antagonists in patients with atrial fibrillation and cognitive function disturbances].

The incidence of atrial fibrillation (AF) and of thromboembolic complications increases along with age. This is also the case for cognitive function disturbances; therefore their occurrence in patients (pts) with AF may hamper control of anticoagulant therapy and maintenance of therapeutic INR values. The aim of the study was to evaluate the effect of cognitive function disturbances on implementation and monitoring of the treatment with oral vitamin K antagonists (VKA) in patients with AF. The relationship between the level of cognitive function disturbances and the severity of experienced AF symptoms was defined.The analysis included a group of 93 pts (41 males, 52 females, mean age: 76.8) with a diagnosis of AF and with indications for anticoagulation treatment with VKAs (CHA2DS2VASc > or = 2, HAS-BLED < 3), referred to the Clinic of Internal Diseases and Clinical Pharmacology of the Medical University of Lodz. In a group of pts (n = 46) treated chronically with VKAs, mean INR values at admission to the hospital were calculated and the number of results falling within the therapeutic range of 2-3, by the severity of cognitive disturbances, was analyzed. Cognitive abilities were assessed with the Mini Mental State Examination Scale (MMSE) (MMSE-Mini-mental state examination). The EHRA (European Heart Rhythm Association) classification was used to assess AF-related complaints.The 93 studied subjects were divided into 3 groups: group I with normal cognitive function (MMSE = 24-27) - n = 35; group II with disturbances of cognitive function without dementia (MMSE = 24-26) - n = 35 and group III with dementia (MMSE < 24) - n = 23.66% of pts with normal MMSE result were referred to the hospital because AF-related symptoms and in the group of patients with MMSE < 24 these symptoms were the cause of hospitalization in 23% of pts. Despite the fact that all patients had indications for VKAs, this treatment was not started in 40%, 51.4% and 65% of pts in group I, II and III, respectively. At admission to the hospital, therapeutic level INR values were found only in 34.8% of AF pts. 49% of pts were treated with VKAs in total. In group II, a high percentage of patients (43%) treated with aspirin was found in spite of high thromboembolic risk and no contraindications to VKAs. About 23% of pts with a normal MMSE result and 14% of pts in group II experienced AF-related symptoms preventing them from normal functioning and performing daily activities (EHRA IV). Nobody in group III reported severe AF-related symptoms.Along with the advancing age, there is an increase of the incidence of persistent and fixed atrial fibrillation, of the risk of thromboembolic complications and of the severity of cognitive function disturbances. Treatment with oral vitamin K antagonists was implemented much less frequently among patients with atrial fibrillation and cognitive function disturbances, as compared to the patients with normal cognitive function. The MMSE test should be routinely performed in patients with atrial fibrillation to monitor the efficacy and safety of the treatment with oral vitamin K antagonists properly. In patients with disturbances of cognitive function, significantly lower reportability of AF-related complaints was shown, as compared to individuals without these disturbances. Patients with normal MMSE result were referred to the hospital because AF-related symptoms, in the group of patients with MMSE < 23 the main reason for hospitalization was the severity of the symptoms heart failure. ECG should be a routine test performed in elderly patients with cognitive function disturbances or with dementia to detect atrial fibrillation.