Perbandingan efektivitas Allopurinol dan Metilprednisolon dalam mengurangi cedera reperfusi pada bedah pintas arteri koroner : kajian terhadap kadar Malondialdehyde, skor inotropik dan vasoaktif, dan kejadian atrial fibrilasi pascabedah = Comparison of the effectiveness of Allopurinol and Methylprednisolone in reducing reperfusion injury in coronary artery bypass surgery: study of Malondialdehyde levels, Vasoactive-Inotropic Score, and the occurrence of postoperative atrial fibrilation