Factors Associated with the Types of Heparin used in the Treatment of Unstable Angina at a Brazilian Hospital

Unfractionated heparin (UFH) and low-molecularweight heparins (LMWHs) are widely used in curative and preventive treatments of thromboembolic disorders. The aim of the study was to investigate factors associated with the choice of these types of heparin to treat patients with unstable angina under real conditions of hospital use. A cross-sectional study was performed in a private general hospital in Belo Horizonte, Brazil, from January 1st to December 31th, 2001. Data were collected from the hospital electronic database. Inpatients with angina who received enoxaparin or UFH were included in the survey. Data for 555 patients were recorded, including 401 treated with enoxaparin and 154 with UFH. Univariate analysis showed that male and elderly people predominated in both groups, with no statistical difference in the proportions (p>0.05). Multivariate analysis showed 4 factors associated with the use of enoxaparin: cardiac revascularization surgery (OR=0.434), arrhythmias (OR=9.343), risk factors for coronary artery disease (OR=1.333) and private health insurance (OR=0.297). Thus, clinical and organizational factors were associated with the type of heparin used by patients with unstable angina at this hospital. Further drug utilization studies are necessary to expand and improve the data available on the use of heparins in the hospital setting. Keywords : Hospital pharmacy/assessment. Angina pectoris/treatment. Heparin/prescription. Enoxaparin/prescription. RESUMO Fatores associados com os tipos de heparina usados no tratamento da angina instavel em um hospital brasileiro A heparina nao-fracionada (HNF) e heparinas de baixo peso molecular (HBPM) sao amplamente utilizadas em tratamentos curativos e preventivos de tromboembolismo. O objetivo do estudo foi investigar os fatores associados com a escolha desses tipos de heparinas para tratar pacientes com angina instavel sob as condicoes reais de uso hospitalar. Trata-se de um estudo transversal realizado em hospital geral privado, na cidade de Belo Horizonte,MG Brasil, no periodo de Janeiro a Dezembro de 2001. Para a coleta de dados, utilizou-se o banco de dados informatizado do referido hospital. Pacientes internados com angina que receberam enoxaparina ou HNF foram incluidos no estudo. Registrou-se dados de 555 pacientes, incluindo 401 tratados com enoxaparina e 154 com HNF. Na analise univariada, observouse que o genero masculino e pacientes idosos foram predominantes em ambos os grupos, sem diferenca estatistica entre as proporcoes (p>0,05). A analise multivariada revelou quatro fatores associados ao uso de enoxaparina: cirurgia de revascularizacao cardiaca (OR=0,434), arritmias (OR=9,343), fatores de risco para doenca coronariana (OR=1,333) e atendimento por plano de saude (OR=0,297). Assim, fatores clinicos e organizacionais estao associados com o tipo de heparina usado por pacientes com angina instavel, neste hospital. A realizacao de mais estudos de utilizacao de medicamentos e necessaria para aprimorar o conhecimento sobre o uso de heparinas, em hospitais. Palavras-chave : Farmacia hospitalar/avaliacao. Angina pectoris/tratamento. Heparina/consumo. Enoxaparina/consumo.