Objective: This study aims to assess the condition of cardiac histopathology through hematoxylin-eosin staining in 5/6 subtotal nephrectomyconditions.Methods: Fifteen male Swiss mice aged 3–5 months will be grouped into 3 treatment groups, namely the nephrectomy group (JSN, n=5), shamoperation (JSO, n=5), and simvastatin 20 mg/kg body weight (JSIM, n=5). The histopathology of the heart will be assessed blindly. Severity is assessedbased on scoring using a scale (−) no damage, (+) mild, (++) medium, and (+++) heavy. Assessment of severity refers to the irregularity of the heartmuscle, increased amount of connective tissue, myofibril hypertrophy, myofibril swelling, sarcoplasmic fragmentation, sarcoplasmic vacuolization,bleeding in a myofibril, myofibril degeneration, cardiomyocyte damage, and the presence of acidophilic cytoplasm.Results: The results showed no morphological changes in heart muscle tissue in the JSO group except for fragmentation and vacuolization in minimalamounts of sarcoplasm (+), whereas in the JSN and JSIM groups, there was moderate damage to sarcoplasm (++) and minimal changes in myofibrils(hypertrophy and bleeding) (+). The JSN group also found severe damage (+++) to the irregularity of the heart muscle, whereas in JSIM, only moderatedamage was found (++) to the irregularity of the heart muscle.Conclusion: Simvastatin seems to be able to correct the irregularity of the heart muscle in the condition of 5/6 subtotal nephrectomy.