RESUMO
BACKGROUND: Cardiotoxicity is the major side effect of doxorubicin. As mechanisms that are involved in cardiotoxicity are ambiguous, new methods for attenuating cardiotoxicity are needed. Recent studies have shown that bisphosphonates can decrease oxidative stress. Therefore, the objective of this study was to evaluate the effect of pamidronate on preventing acute doxorubicin-induced cardiotoxicity. METHODS: Sixty-four male Wistar rats were allocated into four groups: the control group (C), the pamidronate group (P), the doxorubicin group (D) and the doxorubicin/pamidronate group (DP). The rats in the P and DP groups received pamidronate injections (3 mg/kg, IP). After 24 hours, the rats in the D and DP groups received doxorubicin injections (20 mg/kg, IP). Forty-eight hours after doxorubicin injection, the rats were killed. Echocardiography, isolated heart study and biochemical analysis were performed. RESULTS: Doxorubicin-induced acute cardiotoxicity showed increased matrix metalloproteinases (MMP)-2 activation, oxidative damage and induced alterations in myocardial energetic metabolism. Pamidronate did not inhibit MMP-2 activation but attenuated oxidative stress and improved myocardial energetic metabolism. Regarding cardiac function, the DP group exhibited a decrease in the left ventricular ejection fraction in the echocardiography and a decrease in +dP/dt in the isolated heart study compared with other groups. The same DP group presented serum hypocalcaemia. CONCLUSIONS: Despite its ability to reduce oxidative stress and improve energy metabolism in the heart, pamidronate worsened systolic function in rats treated with doxorubicin, and therefore we cannot recommend its use in conjunction with anthracycline chemotherapy.
Assuntos
Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/fisiopatologia , Difosfonatos/farmacologia , Doxorrubicina/efeitos adversos , Metabolismo Energético/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Cálcio/sangue , Cardiotoxicidade/sangue , Diástole/efeitos dos fármacos , Difosfonatos/uso terapêutico , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Ecocardiografia , Ativação Enzimática/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Técnicas In Vitro , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Miocárdio/enzimologia , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Pamidronato , Perfusão , Ratos Wistar , Resultado do TratamentoRESUMO
INTRODUCTION:: The mortality rate attributed to ST-segment elevation myocardial infarction (STEMI) has decreased in the world. However, this disease is still responsible for high costs for health systems. Several factors could decrease mortality in these patients, including implementation of cardiac intensive care units (CICU). The aim of this study was to evaluate the effect of CICU implementation on prescribed recommended treatments and mortality 30 days after STEMI. METHOD:: We performed a retrospective study with patients admitted to CICU between 2005 and 2006 (after group) and between 2000 and 2002, before CICU implementation (before group). RESULTS:: The after group had 101 patients, while the before group had 143 patients. There were no differences in general characteristics between groups. We observed an increase in angiotensin-converting enzyme inhibitors, clopidogrel and statin prescriptions after CICU implementation. We did not find differences regarding number of patients submitted to reperfusion therapy; however, there was an increase in primary percutaneous angioplasty compared with thrombolytic therapy in the after group. There was no difference in 30-day mortality (before: 10.5%; after: 8.9%; p=0.850), but prescription of recommended treatments was high in both groups. Prescription of angiotensin-converting enzyme inhibitors and beta-blocker decreased mortality risk by 4.4 and 4.9 times, respectively. CONCLUSION:: CICU implementation did not reduce mortality after 30 days in patients with STEMI; however, it increased the prescription of standard treatment for these patients.
Assuntos
Unidades de Cuidados Coronarianos/estatística & dados numéricos , Infarto do Miocárdio com Supradesnível do Segmento ST/mortalidade , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Prescrições de Medicamentos/estatística & dados numéricos , Feminino , Mortalidade Hospitalar , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
Summary Introduction: The mortality rate attributed to ST-segment elevation myocardial infarction (STEMI) has decreased in the world. However, this disease is still responsible for high costs for health systems. Several factors could decrease mortality in these patients, including implementation of cardiac intensive care units (CICU). The aim of this study was to evaluate the effect of CICU implementation on prescribed recommended treatments and mortality 30 days after STEMI. Method: We performed a retrospective study with patients admitted to CICU between 2005 and 2006 (after group) and between 2000 and 2002, before CICU implementation (before group). Results: The after group had 101 patients, while the before group had 143 patients. There were no differences in general characteristics between groups. We observed an increase in angiotensin-converting enzyme inhibitors, clopidogrel and statin prescriptions after CICU implementation. We did not find differences regarding number of patients submitted to reperfusion therapy; however, there was an increase in primary percutaneous angioplasty compared with thrombolytic therapy in the after group. There was no difference in 30-day mortality (before: 10.5%; after: 8.9%; p=0.850), but prescription of recommended treatments was high in both groups. Prescription of angiotensin-converting enzyme inhibitors and beta-blocker decreased mortality risk by 4.4 and 4.9 times, respectively. Conclusion: CICU implementation did not reduce mortality after 30 days in patients with STEMI; however, it increased the prescription of standard treatment for these patients.
Resumo Introdução: Apesar da diminuição da mortalidade por infarto agudo do miocárdio com supradesnivelamento do segmento ST (IAM-ST) no mundo, a doença ainda acarreta elevados custos e morbidade. Muitas medidas contribuem para a redução da mortalidade, dentre elas a criação de unidades intensivas coronarianas (UCO). Objetivo: Avaliar o impacto da criação de uma UCO na prescrição de tratamentos preconizados e na mortalidade em 30 dias em pacientes com IAM-ST. Método: Foi realizado estudo retrospectivo e foram coletados dados de prontuários de pacientes internados na UCO de 2005 a 2006 (grupo depois). Esses dados foram comparados com dados do serviço de 2000 a 2002, previamente à criação da UCO (grupo antes). Resultados: Havia 101 e 143 pacientes nos grupos depois e antes, respectivamente. Não houve diferenças em relação às características populacionais e às características do infarto entre os períodos. Observamos aumento na prescrição de iECA, clopidogrel e estatinas. Apesar da ausência de mudanças no número de pacientes que receberam terapia de reperfusão, houve aumento de angioplastias primárias em detrimento ao uso de trombolíticos no período posterior à criação da UCO. Não observamos diminuição da mortalidade em 30 dias após IAM-ST (antes: 10,5%; depois: 8,9%; p=0,850), mas a prescrição de tratamentos preconizados foi alta em ambos os períodos. O uso de iECA e de betabloqueador diminuiu o risco de morte em 4,4 e 4,9 vezes, respectivamente. Conclusão: Em pacientes com IAM-ST, a criação da UCO não reduziu a mortalidade em 30 dias, mas houve aumento na prescrição de tratamentos preconizados.