Prolonged Captopril Therapy in Murine Viral Myocarditis

Area of Science:

• Cardiology
• Virology
• Pharmacology

Background:

• Acute myocarditis can lead to chronic heart disease and cardiomyopathy.
• Coxsackievirus B(3) (CB(3)) mouse model used to study myocarditis.
• Previous studies showed early captopril (ACE inhibitor) ameliorated histopathology, while late administration had limited effects.

Purpose of the Study:

• Investigate the effects of prolonged captopril treatment during the chronic phase of CB(3) myocarditis.
• Assess captopril's impact on myocardial fibrosis and mortality in this model.

Main Methods:

• Male CD(1) mice infected with CB(3) and treated with captopril or placebo from day 7 for up to 6 months.
• Evaluated heart-to-body weight ratios, mortality, and myocardial fibrosis using scoring systems and picrosirius red stain (PSR).
• Autopsies performed at 6 and 10 months post-infection.

Main Results:

• Mean heart weights were similar; however, captopril-treated mice had lower body weight and higher mortality at 6 months.
• Significantly reduced mean myocardial fibrosis scores in captopril-treated mice at 6 months (P = .035) and with PSR (P = .045).
• Fibrosis scores were comparable between groups at 10 months.

Conclusions:

• Prolonged captopril treatment in CB(3) myocarditis effectively reduces myocardial fibrosis in the chronic phase.
• While showing antifibrotic effects, chronic captopril treatment was associated with increased mortality in this specific model.