Quantification of Incomplete Revascularization and its Association With Five-Year Mortality in the Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) Trial Validation of the Residual SYNTAX Score

Abstract

Background-The residual Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery(SYNTAX) Score is an objective measure of the degree and complexity of residual stenosis after percutaneous coronary intervention (PCI). Methods and Results-In the randomized PCI cohort of the SYNTAX Trial (n=903), the baseline and residual SYNTAX Scores were calculated. Subjects with a residual SYNTAX Score of 0 were defined as having undergone complete revascularization (CR), and a residual SYNTAX Score >0 as incomplete revascularization (ICR). Five-year clinical outcomes were stratified by CR and ICR (tertiles of the residual SYNTAX Score: >0-4, >4-8, and >8). In the PCI cohort, the mean baseline and residual SYNTAX Scores were 28.4±11.5 and 4.5±6.9, respectively. The mean Δ SYNTAX Score (representative of the burden of disease removed by PCI) was 23.8±10.9. The residual SYNTAX Score was distributed as follows: CR, 0 (n=386, 42.7%); ICR, >0 to 4 (n=184, 20.4%), >4 to 8 (n=167, 18.5%), >8 (n=153, 16.9%). A progressively higher residual SYNTAX Score was shown to be a surrogate marker of increasing clinical comorbidity and anatomic complexity. Subjects with CR or residual SYNTAX Scores ≤8 had comparable 5-year mortality (CR, 8.5%; residual SYNTAX Score >0-4, 8.7%; >4-8, 11.4%; P=0.60). A residual SYNTAX Score >8 was associated with 35.3% all-cause mortality at 5-years (P<0.001). Stratified analyses in the predefined medical treated diabetic and left main subgroups yielded similar results. Conclusions-The

Differential Clinical Outcomes Between Angiographic Complete Versus Incomplete Coronary Revascularization, According to the Presence of Chronic Kidney Disease in the Drug‐Eluting Stent Era

“…These results are in line with the substudy of the SYNTAX trial, which demonstrated that higher residual SYNTAX score was associated with higher rates of any revascularization 7. Interestingly, the risk of target lesion revascularization was comparable between the angiographic CR and IR groups, and most revascularization events in the IR group were because of progression of residual disease.…”

“…Regarding the clinical relevance of angiographic CR, previous studies have shown conflicting results. Some reports in the pre‐DES era showed the clear benefit of angiographic CR rather than IR, and adverse clinical events related to the residual disease after PCI 3, 4, 5, 6, 7, 8. However, other studies reported unclear benefit of angiographic CR over IR 15, 16, 17.…”

“…Although previous studies suggested that angiographic complete revascularization (CR) was more advantageous than incomplete revascularization (IR) and residual disease was associated with adverse clinical outcome after PCI,3, 4, 5, 6, 7, 8 the evidence regarding the benefit of angiographic CR over IR has been limited in CKD patients with multivessel CAD. Given the increasing prevalence of CKD, it would be an important issue to clarify the safety and efficacy of angiographic CR in this high‐risk population 1, 9.…”

A Tale of Two Techniques: Demystifying the Myth

“…Moreover, incomplete revascularization and anatomical complexity (residual SYNTAX score) have been directly correlated to late all-cause mortality following PCI. 11,35,36 This was demonstrated in the PCI arm of the ULMCA subgroup of SYNTAX, for which the incidence of 5-year all-cause mortality was shown to markedly increase in subjects with a SYNTAX score ≥ 33 (5-year mortality of 20.9%) compared with subjects with a SYNTAX score < 33 (5-year mortality of 7.9%). Conversely, in subjects undergoing CABG, anatomical complexity was shown to not affect longterm prognosis, as exemplified in the CABG arm of the ULMCA subgroup of SYNTAX, for which the incidence of 5-year all-cause mortality remained almost unchanged in subjects with a SYNTAX score ≥ 33 (5-year mortality of 14.1%) compared with subjects with a SYNTAX score < 33 (5-year mortality of 15.1%).…”

Invasive or non-invasive imaging for detecting high-risk coronary lesions?

“…However, the small number of the reported events and the fact that this analysis did not take into account the angiographic variables associated with clinical outcomes (i.e. the Syntax score, or the residual Syntax score) did not allow us to draw safe conclusions about the additive prognostic value of CTCA in this population [149][150][151][152].…”