Impact of the SYNTAX score on mortality in older adults treated with percutaneous coronary intervention

Background Elderly patients (≥75 years) with coronary artery disease (CAD) became an increasing patient population in real life practice. Treatment strategies are hot topics in elderly patients with CAD. Recently, randomized SENIOR-RITA trial demonstrated that routine invasive therapy did not reduce cardiovascular death or myocardial infarction compared with conservative therapy [1]. Purpose We aimed to determine the role of SYNTAX score in elderly patients undergoing percutaneous coronary intervention (PCI) in terms of in-hospital and long term all-cause mortality. Methods A total of 236 elderly patients undergoing PCI between January 2017 and April 2023 from our hospital enrolled to the analysis. 82 non-ST segment elevation myocardial infarction patients, 90 ST segment elevation myocardial infarction patients, 12 unstable angina patients and 52 chronic coronary syndromes patients were enrolled. Clinical, procedural and follow-up data was obtained from the medical records. The SYNTAX score was calculated for each patient using SYNTAX score calculator, version 2.28[2] and patients were divided into 2 groups: Low SYNTAX score group (SYNTAX score ≤22) and medium-high SYNTAX score group (SYNTAX score >22). All-cause mortality was described as the primary outcome. Results Out of 236 elderly patients; 193 patients were assigned to the low SYNTAX score group and 43 patients were assigned to the medium-high SYNTAX score group. Patients were followed for median 39 months. There was no significant difference between 2 groups in terms of diabetes, hypertension, dyslipidaemia, CAD and clinical presentation (Table 1). Median SYNTAX score was 12 in low SYNTAX score group and 28 in medium-high SYNTAX score group. Median troponin and Pro-BNP values were significantly higher in medium-high SYNTAX score group in comparison with low SYNTAX group (2213 vs. 3521, p=0.03 and 0.79 vs. 3, p=0.002; respectively). Ejection fraction was significantly lower in the low SYNTAX score (44% vs. 40%, p=0.04). There was no significant difference in terms of in hospital mortality, MI, stent thrombosis, stroke, major bleeding between two groups. All-cause mortality was likely higher in medium-high SYNTAX score group in comparison with low SYNTAX group at the follow-up (35% vs. 51%, p=0.06). The Pro-BNP level was related with the mortality (hazard ratio [HR]: 1.00, 95% confidence interval [CI]: 1.00–1.00, p<0.004). Besides, postdilatation was independently associated with the mortality (HR: 4.29, 95% CI: 2.06–8.93; p=0<001) (Table 2). Conclusion Our study demonstrated that the SYNTAX score did not impact in-hospital mortality in older (≥75 years) patients treated with PCI. On the other hand, all-cause mortality was likely higher in those patients with medium-high SYNTAX score in comparation with low SYNTAX score group in long term follow-up. Besides, Pro-BNP level and postdilatation as a technical aspect were independently associated with all-cause mortality in long term follow-up.