Heart TeamSYNTAX Score II Revascularization Guide
Anatomy & Demographics
22
Simple (0)Complex (60)
Clinical Comorbidities
Awaiting Heart Team Input
Input anatomical syntax and patient comorbidities to see the survival-based treatment recommendation.
Guidelines & Evidence
Verified
Last Review: 2026
When to Use
When to Use SYNTAX Score II
Patients with complex multi-vessel coronary artery disease (CAD) or left main disease being evaluated for revascularization by the Heart Team
To assist the "Heart Team" (interventional cardiologist + cardiac surgeon) in deciding between Percutaneous Coronary Intervention (PCI) and Coronary Artery Bypass Grafting (CABG)
To predict 4-year all-cause mortality for both interventional strategies (individualized risk prediction, not just group-level)
When anatomical SYNTAX score alone is insufficient (e.g., SYNTAX 32 in a 78-year-old with COPD and chronic kidney disease — surgery risk high, so PCI may be preferred despite high anatomical complexity)
To identify "treatment equipoise" (predicted 4-year mortality within 2% between PCI and CABG) — in these cases, patient preference dominates
For patients with complex CAD (three-vessel disease with or without left main, SYNTAX score ≥ 22) where guidelines recommend Heart Team discussion
When calculating the incremental benefit of CABG over PCI in specific patient subgroups (e.g., diabetic patients show larger CABG benefit at younger age but attenuated at older age)
For patient counseling: presenting personalized mortality estimates (e.g., "Your predicted 4-year mortality with PCI is 8% vs 15% with CABG; PCI is recommended given your age and lung disease")
Key Distinction: SYNTAX Score I vs SYNTAX Score II
| Feature | SYNTAX Score I (Anatomical) | SYNTAX Score II (Clinical + Anatomical) | Why SYNTAX II Improves Decision-Making |
|---|---|---|---|
| Input variables | Pure angiographic assessment: lesion location, bifurcations, CTO, calcification, tortuosity, thrombus, diffuseness (16 segments, weighted modifiers) | 8 variables: SYNTAX Score I + age, creatinine clearance (CrCl), LVEF, gender, COPD, PAD, left main disease, (plus anatomical score) | Adds patient frailty, competing risks, and organ dysfunction that modify surgical risk |
| Output | Continuous score (0-60+) with tertiles: low ≤22, intermediate 23-32, high ≥33 | 4-year predicted mortality for PCI and CABG separately (e.g., "PCI 12%, CABG 8%") | Provides absolute mortality estimates, not just complexity strata |
| Primary use | Stratify anatomical complexity; first filter for PCI vs CABG decision | Individualize mortality prediction; guide Heart Team discussion; identify treatment equipoise | Prevents over-reliance on anatomy alone (e.g., elderly with high SYNTAX may still benefit from PCI due to surgical risk) |
| Guideline endorsement | ESC 2018: Class I for risk stratification in multivessel CAD | ESC 2018: Class IIa for revascularization decision-making (higher level for SYNTAX II than SYNTAX I alone for treatment choice) | ESC guidelines specifically recommend SYNTAX II over SYNTAX I alone for decision-making in complex CAD |
| Validation cohorts | SYNTAX trial (n=1,800), multiple external registries | SYNTAX derivation + validation in DELTA registry (n=2,280) + EXCEL trial (n=1,805) + FREEDOM trial (n=1,900) | Validated in multiple independent cohorts; c-index for mortality 0.77 vs 0.62 for SYNTAX I alone (p<0.001) |
Limitations of SYNTAX Score II (What It Does Not Include)
Frailty (gait speed, grip strength, activities of daily living) — not captured by age or CrCl; frail elderly have higher surgical mortality even with normal CrCl and LVEF.
STS PROM Score (Society of Thoracic Surgeons predicted risk of mortality) — SYNTAX II does not include specific cardiac surgery risk factors (recent MI, cardiogenic shock, prior cardiac surgery, porcelain aorta, mediastinal radiation), which independently predict CABG mortality.
Diabetes duration and complication status (SYNTAX II includes diabetes as part of PAD? No, diabetes not in model at all! Key omission given diabetes strongly favors CABG in FREEDOM trial). SYNTAX II does NOT contain diabetes as a predictor (criticism).
Glycemic control (HbA1c) — diabetic patients with HbA1c > 7.5% have higher surgical infection risk and worse vein graft patency, not accounted for.
Left ventricular function as continuous variable (categorized: <30%, 30-50%, >50% in original model); borderline LVEF 45% may be imprecise.
Chronic kidney disease stage (SYNTAX II uses CrCl, but not dialysis status — dialysis patients have extremely high mortality with CABG ~15% 30-day, not well captured).
Prior stroke or cerebrovascular disease (predicts post-CABG stroke risk, not in model).
Operative urgency (elective vs urgent vs emergent CABG has 10-fold mortality difference — SYNTAX II assumes elective only).
Last Comprehensive Review: 2026