The impact of the SYNTAX score on the incidence of in-hospital cardiac arrest in patients with acute coronary syndrome undergoing percutaneous coronary intervention: a retrospective cohort study

Abstract Background The SYNTAX score (SS) quantifies the severity and complexity of coronary artery lesions and serves as an independent predictor of major adverse cardiovascular events and mortality in patients with acute coronary syndrome (ACS). However, few studies have examined the association between SS and in-hospital cardiac arrest (IHCA) in this population. Therefore, this study aims to elucidate the relationship between SS and the incidence of IHCA in patients with ACS. Methods This study consecutively enrolled 3,224 patients undergoing percutaneous coronary intervention (PCI). Logistic regression and restricted cubic spline (RCS) analyses were employed to examine the association between SS and the incidence of IHCA. Participants were stratified into three groups based on SS: Group T1 (SS ? 10, N = 1,097), Group T2 (10 < SS ? 18, N = 1,089), and Group T3 (SS > 18, N = 1,038). The primary endpoint was the incidence of IHCA. Results The overall incidence of IHCA was 4% (N=147). After adjusting for covariates, SS was significantly associated with the incidence of IHCA in ACS patients treated with PCI (OR = 1.0400; 95% confidence interval (CI) = 1.0200?1.0700; p < 0.001). Compared with the T1 group, the T3 group exhibited an increased risk of IHCA (OR = 2.1800; 95% CI = 1.2900?3.6900; p = 0.0040). Subgroup analyses revealed that, after covariate adjustment, patients with ST-segment elevation myocardial infarction (STEMI) had an increased risk of IHCA (OR = 1.0700; 95% CI = 1.0300?1.1100; p < 0.001). Similarly, both patients with diabetes mellitus (DM) (OR = 1.0400; 95% CI = 1.000?1.0700; p = 0.0270) and those without DM (OR = 1.0600; 95% CI = 1.0200?1.1000; p = 0.0020) showed an increased risk. Furthermore, elderly patients (?60 years) (OR = 1.0300; 95% CI = 1.0100?1.0700; p = 0.0210) and non-elderly patients (<60 years) (OR = 1.0500; 95% CI = 1.000?1.1000; p = 0.0470) had an increased risk, as did male patients (OR = 1.0500; 95% CI = 1.0200?1.0700; p = 0.0020). RCS analysis indicated a dose-response relationship between IHCA incidence and SS (nonlinear p-value = 0.906), with the risk of IHCA increasing when SS exceeded 23.975. Incorporating SS into the baseline risk model improved the predictive value for IHCA incidence in ACS patients undergoing PCI (Net reclassification improvement [NRI]: 0.3537 [0.1906?0.5167], p < 0.001; Integrated discriminant improvement [IDI]: 0.0104 [0.0025?0.0183], p = 0.0097). Conclusions Among patients with ACS undergoing PCI, SS is significantly associated with the incidence of IHCA. Consequently, SS may serve as an effective predictor of IHCA in this population.