This study compares the effectiveness of del Nido and cold blood cardioplegia in high-risk patients with reduced ejection fraction undergoing isolated coronary artery bypass grafting. With 45 patient pairs matched for several factors, the research found that del Nido cardioplegia resulted in a higher rate of spontaneous return to sinus rhythm post-surgery and showed a trend towards lower creatine kinase release and atrial fibrillation rates, though mortality and major adverse cardiac events were similar between the two groups. The findings suggest del Nido cardioplegia may offer satisfactory myocardial protection in this patient demographic, highlighting the need for further prospective trials.