Avaliação da função diastólica do ventrículo esquerdo na miocardiopatia chagásica em três etapas de tratamento da insuficiência cardíaca: convencional, otimizada e associada ao emprego de carvedilol

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

14/10/2009

RESUMO

Chronic Chagas cardiomyopathy causes substantial morbidity and mortality in Latin America and its prognosis is dependent on systolic and diastolic left ventriclar (LV) function. Whether renin-angiotensin system (RAS) inhibitors and beta-blockers are safe and beneficial in this group of patients has been challenged because of the lack of formal trials. Objective: The objective of this study was to determine the efficacy of renin-angiotensin system (RAS) inhibitors and beta-blockers in improving diastolic dysfunction in chronic Chagas cardiomyopathy. Methods: We conducted a double-blind, placebo-controlled, and randomized trial in 41 patients with Trypanosoma cruzi infection and cardiomyopathy. All patients received enalapril (up-titrated to 20 mg BID) and spironolactone (25 mg QD). Subsequently, the patients were randomly assigned to receive placebo (n=20) or carvedilol up-titrated to 25 mg BID (n=19). The end points were changes in LV diastolic function parameters evaluated by transthoracic Doppler echocardiography after RAS inhibition and that after the addition of carvedilol, and change in brain natriuretic peptide (BNP) levels, used as a surrogate marker of LV filling pressure. Results: Optimization of RAS inhibition was safe and associated with improvement in LV diastolic function parameters: isovolumic relaxation time (137.47 ms vs. 151.55 ms, p=0.02), increase of inferior wall E velocity (6.55 cm/s vs. 7.30 cm/s, p=0.03), decrease of inferior E/E index (9.23 vs. 8.36, p=0.065), and increase of antero-lateral wall A (6.05 vs. 6.78, p=0.02). BNP levels decreased significantly [95.90 vs 32.55; p=0.026]. Treatment with carvedilol was associated with a trend toward a preservation of diastolic parameters: decrease in systolic pulmonary venous flow index (0.52 vs. 0.48, p=0.029), and a decrease in inferolateral wall E velocity in placebo group (6.55 cm/s vs. 7.30 cm/s, p=0.03), both not observed in the carvedilol group. LV flow propagation velocity decreased in the first stage of treatment and increased after carvedilol association (24.31cm/s vs. 30.60 cm/s, p=0.004). There was no significant change in BNP levels [86.95 (123.05) vs. 31.40 (184.38); p=0.525]. Conclusions: In patients with chronic Chagas cardiomyopathy, optimizatin of treatment with enalapril and spironolactone was associated with significant benefits in LV diastolic cardiac function and a decrease of BNP levels, and subsequent addition of carvedilol was associated with a trend toward a prevention of worsening of diastolic dysfunction, without changes in BNP levels. Key Words: diastolic function, heart failure, Chagas cardiomyopathy, brain natriuretic peptide, echocardiography

ASSUNTO(S)

chagas, doença de. doença de chagas decs doenças cardiovasculares decs função ventricular esquerda decs cardiomiopatia chagásica decs tese da faculdade de medicina da ufmg insuficiência cardíaca decs dissertações acadêmicas decs

ACESSO AO ARTIGO

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