Use of the SYNTAX Score II to predict mortality in interventional cardiology A systematic review and meta-analysis

Background: As the SYNTAX Score has limitations, it should be replaced by another better angiographic tool. By comparing mortality that was observed following percutaneous coronary intervention (PCI) in patients who were allotted a low versus a high score, we aimed to systematically investigate mortality prediction using the SYNTAX Score II in Interventional Cardiology. Methods: Electronic databases were searched for relevant publications using the terms "SYNTAX Score II and percutaneous coronary intervention." The main outcome was all-cause mortality. This analysis was carried out by the RevMan 5.3 software [risk ratios (RRs) and 95% confidence intervals (95% CIs) were calculated]. Results: A total number of 9443 participants were enrolled for this analysis. As different studies reported different range of SYNTAX Score II, we further classified these scores range into 4 different groups: 17 <SS> 17, 20 <SS> 20, 22 <SS> 22, and 26 <SS> 26 appropriately. Results of this analysis showed that the risk of mortality in patients with a high SYNTAX Score II (SS>17) was significantly higher (RR: 2.65, 95% CI: 1.05-6.73; P=.04) than patients with a low SYNTAX Score II (SS<17). Even when participants with a low SYNTAX Score II (SS<20) were compared with patients who were assigned to a higher SYNTAX Score II (SS>20), a significantly higher risk of mortality was associated with a high SYNTAX Score II (RR: 3.73, 95% CI: 1.99-6.96; P=.0001). Conclusion: Following PCI, the risk of mortality was higher in those patients with a high SYNTAX Score II. The SYNTAX Score II might be considered as an important tool to predict mortality in Interventional Cardiology. Future research should further explore the benefits of this tool.