Thromboembolic and/or bleeding complications in patients under oral anticoagulation followed at a tertiary hospital.
A better understanding of the characteristics of patients that come to the anticoagulation (AC) clinic of a tertiary hospital could lead to better healthcare provision and reduce the number of thromboembolic and bleeding complications.


OBJECTIVE
To evaluate the characteristics of patients followed at our AC clinic and to determine which factors could predict an increased risk of complications.


METHODS
Data obtained by doctors through a questionnaire from patients attending the AC clinic of our hospital were analyzed. Demographic characteristics (gender, age, literacy, educational level), classical coronary artery disease (CAD) risk factors, the diagnosis that led to oral anticoagulation therapy (OAT) and its duration, the number of INR determinations, the minimum, maximum and current INR value and complications of OAT were studied. Complications were defined as bleeding and/or thromboembolic events occurring during the course of OAT.


RESULTS
Of the 101 patients enrolled, 74 were female (73.3%), with a mean age of 6410 years (21-85). This population had had 4.53.5 years of schooling and there was a 15% incidence of illiteracy. The main reason for OAT was mechanical valve prosthesis implantation (56.4%). Each patient had an average of one CAD risk factor. The mean number of months of OAT was 99.489 (1-360). Sixty-six patients (65.3%) knew the reason for the therapy. Each patient had 1.20.6 INR determinations per month. Forty-five patients had bleeding and/or thromboembolic complications during OAT. There were 50 bleeding complications in 41 patients, seven leading to hospital admission. There were 7 thromboembolic events (central or peripheral), in 7 patients. The patients were divided into two groups: group I--with complications (GI) and group II--without complications (GII). There were 45 patients in GI, mean age 63.59.1 years (39-80), and 56 patients in GII, mean age 64.711.3 years (21-85). A greater number of complications were found in patients with mitral valve mechanical prostheses (GI--60.6%; GII--9.4%; p = 0.024). More complications were also found in patients with recommended maximum INR >3 (GI--55.2; GII--44.8; p = 0.013) and in those who had undergone dental procedures (GI--68.3%; GII--31.7; p < 0.001). The duration of OAT had the greatest predictive value for the development of complications (GI--138.196.5 months; GII--67.868.2 months; p < 0.00005). Multivariate analysis identified OAT duration as the only independent predictive factor.


CONCLUSIONS
The high percentage of illiteracy found in this observational study could have hindered understanding of this sometim&e complex therapy. However, in our study this was not a significant predictor of complications. The predictive factors for bleeding and/or thromboembolic complications during OAT were the duration of therapy, the recommended maximum INR value and dental procedures. After multivariate analysis only the first variable was shown to be significant in this context.
Pelicano
Nuno
N
Serviço de Cardiologia, Hospital de Santa Marta, Lisboa. nunopelicano@sapo.pt
Branco
Luísa Moura
LM
Pinto
Anabela
A
Sá
Ana
A
Timóteo
Ana Teresa
AT
Feliciano
Joana
J
Fiarresga
António
A
Agapito
Ana F
AF
Palma
M Conceição
MC
Quininha
Jorge
J
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000150:complications; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D013923:Thromboembolism / Q000139:chemically induced* / Q000209:etiology
D000925:Anticoagulants