Introduction This study aims to compare the outcomes of minimally invasive coronary artery bypass grafting surgery (MICS CABG) versus median sternotomy (MS CABG) within an established minimally invasive cardiac surgical programme in Singapore. Methods We retrospectively analysed 111 propensity-score matched pairs of patients who underwent MICS CABG or MS CABG between January 2009 and February 2020 at the National University Heart Centre, Singapore. Minimally invasive direct coronary artery bypass (MIDCAB) patients were matched to single or double graft MS CABG patients (Group 1) while multivessel MICS patients were matched to MS CABG patients with the corresponding number of grafts (Group 2). Results 111 propensity matched pairs were obtained. The EuroSCORE II in the matched group cohorts were comparable (p=0.846). In both single and multivessel groups, MICS patients experienced shorter postoperative length of stay (p<0.001) and lower rates of prolonged ventilation (p=0.041) . Intraoperative transfusion rates and other postoperative outcomes were comparable between MICS and MS patients in the single and multivessel groups.mortality, reintervention heart failure rates were also comparable at 1 year follow up. In Group 1, no significant differences in procedural duration (p=0.574) and cardiopulmonary bypass duration (p=0.699) were noted. Moreover, MIDCAB patients had a smaller drop in postoperative haemoglobin levels (p<0.001). In Group 2, cardiopulmonary bypass (p=0.097) and length of procedure (p<0.001) were longer among multivessel MICS patients but did not translate to adverse postoperative events. Conclusion MICS CABG is a safe and effective approach for surgical revascularisation of coronary artery disease.

ABSTRACT Background/Objective: To examine N-acetylcysteine’s renoprotective effect in adult cardiac surgery Methods: PubMed, Ovid Medline, and Embase were searched for randomised controlled trials published between January 1990 and November 2019 that investigated the effect of N-acetylcysteine in preventing acute kidney injury in patients undergoing cardiac surgery. Cochrane Library was searched to identify any prior systematic review or meta-analysis. Eligibility Criteria: Randomised controlled trials that assessed the effect of N-acetylcysteine in comparison to placebo by measuring the incidence of acute kidney injury. Two independent reviewers extracted the data and assessed the risk of publication bias of included studies. Results: Overall meta analytic estimates of all 10 included trials was controversial, showing that N-acetylcysteine did not have a significant effect (odds ratio: 0.84, 95% confidence interval 0.64 to 1.10). However further meta analytic estimates comparing the dosage and timing of NAC administered suggested that the administration of high dosages of NAC perioperatively would have significant benefit in preventing acute kidney injury. Conclusion: This study suggests that N-acetylcysteine must be administered at high dosages perioperatively to have a significant effect in reducing the incidence of acute kidney injury. However, only one out of the 10 included trials administered NAC high dosages perioperatively. Although it is worth noting that it is the only included trial to show a significant benefit in reducing the incidence of acute kidney injury (odds ratio: 0.30, 95% confidence interval 0.11 to 0.81), further studies should be conducted to confirm the renoprotective effect of administering high dosages of NAC perioperatively.