Residual SYNTAX score II: A combination of the assessment of the revascularization degree and the clinical evaluation after percutaneous coronary intervention.

We would like to thank Dr Cerit for his valuable comments on our paper [1]. Firstly, he pointed out, the importance of SYNTAX score II (SS II), integrating anatomical SYNTAX score (SS) with clinical characteristics and allowing an individualized prediction of long-term mortality [2], [3]. Indeed, this latter score has become the gold standard for a better risk stratification in coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI) [4]. We have shown that SS II was able to predict clinical events in not only ideal stable patients, but also in an unrestricted, real world population of patients with Acute coronary syndrome (ACS) and severe CAD [3-vessel disease and/or left main (LM) stenosis] referred to cathlab [1].

Secondly, although some variables included in SS II are still the same following revascularization (age, sex, peripheral arterial disease, and chronic obstructive pulmonary disease), others could be modified by PCI [creatinine clearance, left ventricular ejection fraction (LVEF), anatomical SS, and unprotected LM stenosis] [2]. Indeed, patients could experience contrast induced nephropathy, LVEF might be either improved or impaired according to the success of the procedure and coronary lesions will be treated with the aim to achieve complete revascularization or the lowest possible residual SS (rSS).

In our study, 100 patients were enrolled; LM stenosis was observed in 19% and LVEF was impaired in 35% of cases. Baseline median of SS and SS II were 26 (range, 7–47) and 29 (range, 14–59), respectively [1]. Although all LM lesions were treated, complete revascularization was only achieved in twothirds of patients with a median rSS of 4 (range, 2–18.5) [1]. Following PCI, CIN (contrast induced nephropathy) incidence was 9% in our study, although LVEF either significantly increased or decreased (>5%) in 12% and 1% of cases, respectively. Therefore as suggested, we calculated residual SS II; the median was 13 (range, 6–19). Interestingly, residual SS II ≥ 13 also predicted major adverse cardiac and cerebrovascular events occurrence at 1 year outcome (hazard ratio, 1.93; 95% confidence interval: 1.18–6.81; p = 0.037).

In conclusion, we agree that residual SS II could be of interest to predict midterm outcome in complex ACS patients. Indeed, in addition to “as complete as possible” revascularization, the preservation or the improvement of clinical status (particularly renal function and LVEF) is important to achieve better cardiovascular outcome in this high risk subset of patients.