New risk stratification (ners) score ii – to predict clinical outcome after revascularisation (pci/cabg) of unprotected left main coronary artery disease

Background: Conventional NERS (New Risk Stratification) Score (Fajadet and Chieffo, 2012) are proven to be superior to SYNTAX score in predicting MACE, but involved complex calculation. This is duly addressed by a simplified version, by the NERS Score II. (Kalbfleisch and Hort, 1977) We performed a prospective pilot study to assess efficacy of NERS II to predict clinical outcome in form of MACE and also symptom relief / quality of life, in patients with UPLMCAD (Unprotected left main coronary artery disease) undergoing either PCI or CABG. Methods: Forty-one patients with UPLMCAD undergoing coronary revascularisation (20 PCI + 21 CABG) were included in the study between 1st January, 2013 to 31st Dec 2014 in Amrita institute of Medical sciences and followed up after 1 year of procedure. All the individuals were assessed for MACE, functional class, echo, SAQ score, TMT positivity, and Duke score. All these variables were correlated with pre-procedure NERS II. Results: 9 out of 41 patients had MACE (deaths 5, ACS 3, TVR 1). ROC curves for NERS II showed cut-off value as 16.55 to stratify patients as low and high risk, with a sensitivity of 87.5% and specificity of 81.2%. Although the incidence of MACCE did not vary significantly between 2 NERS II groups. Other parameters of clinical profile like TMT positivity, functional class, Duke and SAQ score were found to have significant between-group difference. Odds-ratio for TMT were positive (OR = 21, 95% CI 1.9412 to 27.21), odds-ratio for functional class (OR = 7.7, 95% CI 1.39 to 42.63), odds-ratio for duke score (OR = 15, 95% CI 2.02 to 11.07). Conclusion: NERS II score is an effective tool to predict clinical outcome in the form of symptom relief in UPLMCAD patients undergoing revascularization. However with respect to MACE event, there was a definite poorer outcome with high NERS II score. No statistical significance was seen between the group differences. This was probably due to lesser number of MACE events. Also a single cut-off score of 16.55 can be used to risk stratify UPLMCAD patients as LOW RISK NERS II (< 16.55), and HIGH RISK NERS II ( >/= 16.55) with statistically significant different outcomes (Sensitivity 87.5%, specificity 81.8%).