The residual SYNTAX Score (rSS) is an angiographic score that assesses residual coronary artery disease (CAD) after percutaneous coronary intervention (PCI). Residual CAD has been associated with worsened prognosis in patients undergoing PCI for acute coronary syndromes (ACS). The association between kidney function with rSS has not been investigated in patients with ACS.

In ACS, we sought to determine whether chronic kidney disease (CKD) patients exhibit more incomplete revascularization as assessed by rSS following stage revascularization procedures by PCI. We evaluated the impact of incomplete revascularization on the occurrence of major cardiovascular events (MACE)

Eight hundred and thirty-one ACS patients undergoing PCI were divided into 3 subgroups according to their estimated Glomerular Filtration Rate (eGFR) levels: 695 patients with eGFR≥60ml/min/1,73m², 108 patients with eGFR<60–30ml/min/1,73m² and 28 patients with eGFR<30ml/min/1.73m². Initial SS and rSS for each patient after stage revascularization were calculated.

Compared with those with preserved eGFR, CKD patients had significantly higher all-cause and cardiovascular mortality (3.6% vs. 11.1% vs. 25%, P<0.0001 and 1.6% vs. 6.5% vs. 10.7%, P<0.0001, respectively), MACE (12% vs. 25.9% vs. 35.7%, P<0.0001). Patients with rSS>8 had higher all cause and cardiovascular mortality (13% vs. 3.4%, P<0.0001 and 8% vs. 1.2%, P<0.0001 respectively), and MACE (25.9% vs. 11.8%, P<0.0001) than those with rSS≤8. Multivariate analysis identified rSS>8 as an independent predictive factor of cardiac death (hazard ratio (HR): 3.38, 95% confidence interval: 1.28 to 8.93; P=0.014) and MACE (HR: 1.63, 95% confidence interval: 1.08 to 2.46; P=0.02). CKD is an independent predictive factor of rSS>8 (HR: 1.65, 95% confidence interval: 1.01 to 2.71;P=0.048) (Table 1, Fig. 1).

In ACS, CKD is predictive of incomplete revascularization which is a strong predictor of adverse cardiovascular outcomes including cardiac death and MACE.