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SYNTAX Score

The Residual SYNTAX Score and Its Impact on Predicting In-Hospital Outcomes in PCI Patients

March 13, 2017

Key Takeaways

  • The SYNTAX score is an angiographic instrument commonly used to grade coronary artery disease (CAD) severity and complexity.
  • In-hospital mortality, acute kidney injury (AKI), and periprocedural death were associated with high residual SYNTAX score (rSS) scores in this study. Similarly, a baseline SYNTAX score (bSS) >22 was also associated with higher unadjusted rates of mortality and net adverse cardiac events (NACE).
  • The rSS score provides a detailed evaluation of residual CAD anatomy and complexity, a potential contributor to its prognostic-like characteristics. rSS >8 was identified as an independent predictor of the primary outcome of NACE in this study.
  • Researchers hypothesized that patients with higher rSS scores may be susceptible to adverse events during and following primary PCI.

The SYNTAX score is an angiographic instrument commonly used to grade coronary artery disease (CAD) severity and complexity. SYNTAX can be divided into two categories: baseline SYNTAX score (bSS) and residual SYNTAX score (rSS). The bSS has previously been associated with greater major adverse cardiac events (MACE) as well as in-hospital and long-term mortality. rSS, however, is used to examine the complexity of residual CAD following primary percutaneous coronary intervention (PCI).

A prospective study in Catheterization and Cardiovascular Interventions examined 243 patients who received primary PCI for ST-elevation myocardial infarction (STEMI).1 Close to half (44%) of selected patients had multivessel disease (MVD), and mean bSS and rSS was 14.1 +/- 8.2 and 4.7 +/- 7.2, respectively. The primary outcome (net adverse cardiac events, or NACE) included a composite of the following:

  • ACUITY-defined major bleeding
  • Congestive heart failure (CHF)
  • Hospital mortality
  • Recurrent myocardial infarction (MI)

Patients with a high rSS consistently showed the following characteristics:

  • Older age
  • Medical history of:
    • Diabetes
    • Hypertension
    • MI
  • Often required emergent CABG and intra-aortic balloon pump counterpulsation
  • Higher rates of NACE

In-hospital mortality, acute kidney injury (AKI), and periprocedural death were also associated with high rSS scores. Similarly, a bSS >22 was also associated with higher unadjusted rates of mortality and NACE. Cardiogenic shock secondary to left or right ventricular pump failure was the prime contributor to mortality in 5 out of 7 cases of patients with high rSS and STEMI.

rSS >8 was identified as an independent predictor of the primary outcome of NACE in this study. Diabetes, prior MI, and MVD were found to be independent predictors of high rSS. The rSS score provides a detailed evaluation of residual CAD anatomy and complexity, a potential contributor to its prognostic-like characteristics.

Researchers hypothesized that patients with higher rSS scores may be susceptible to adverse events during and following primary PCI, since all-cause in-hospital mortality was elevated in the high rSS patient group in this study.

Reference:

  1. Khan R, Al-Hawwas M, Hatem R, et al. Prognostic impact of the residual SYNTAX score on in-hospital outcomes in patients undergoing primary percutaneous coronary intervention. Catheter Cardiovasc Interv. 2016;88(5):740-747. doi:10.1002/ccd.26413

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