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: 2026-07-17
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).
How it Works
SYNTAX Score II Predictors — 8 Variables (7 Clinical + 1 Anatomical)
| Variable | Units/Categories | Effect on PCI Mortality (Increase) | Effect on CABG Mortality (Increase) | Net Effect on Decision (Favor PCI or CABG) | Clinical Rationale |
|---|---|---|---|---|---|
| Anatomical SYNTAX Score (from SYNTAX I) | Continuous (0-60+) | ↑ mortality as SYNTAX increases (moderate effect) | ↑ mortality as SYNTAX increases (but stronger effect for PCI than CABG at high SYNTAX) | High SYNTAX (≥33): favors CABG; Low SYNTAX (≤22): favors PCI (similar mortality) | Complex anatomy increases PCI risk more than CABG (difficult to stent all lesions completely, higher repeat revascularization, stent thrombosis) |
| Age | Continuous (years, mean 65 in derivation, range 30-90) | ↑ risk with age (moderate increase, HR 1.04 per 5 years) | ↑↑ risk with age (stronger increase, HR 1.10 per 5 years, p=0.01 vs PCI) | Older age (> 70 years): favors PCI (surgical mortality rises faster with age than PCI mortality) | Elderly patients tolerate sternotomy, cardiopulmonary bypass, and prolonged ventilation poorly; PCI less invasive preserves quality of life. Example: 80-year-old with SYNTAX 28: PCI mortality 12%, CABG 18% (difference 6% favors PCI) |
| Creatinine clearance (CrCl) | Continuous (mL/min, mean 80, range 15-150) | ↑ risk with lower CrCl (moderate, HR 1.02 per 10 mL/min decrease) | ↑↑ risk with lower CrCl (strong, HR 1.05 per 10 mL/min decrease, p=0.03 vs PCI) | Low CrCl (< 60): favors PCI (CABG risk higher due to acute kidney injury, dialysis, volume overload, and need for contrast in some cases) | Renal impairment increases post-CABG AKI risk (20-30% if CrCl < 60, 5-10% require dialysis). PCI contrast load can be minimized (low/zero contrast techniques) or staged. |
| Left ventricular ejection fraction (LVEF) | Categorical: <30%, 30-50%, >50% (or continuous, but model uses categories) | ↑ risk with low LVEF (HR 1.3 for 30-50%, HR 1.8 for <30% vs >50%) | ↑↑ risk with low LVEF (HR 1.5 for 30-50%, HR 2.5 for <30% vs >50%, p=0.02 vs PCI) | Low LVEF (< 50%): favors PCI (CABG risk of low output syndrome, prolonged inotrope support, acute kidney injury, death higher than PCI) | Poor LVEF (especially < 35%) increases surgical mortality from 1-2% to 5-8% (10× increase). PCI can be staged, done under Impella support if needed. CABG is still beneficial for ischemic cardiomyopathy (STICH trial), but SYNTAX II suggests PCI may be safer in very low EF. |
| Female sex | Binary (male reference) | ↓ mortality vs male (HR 0.85, p=0.04 — protective) | ↑ mortality vs male (HR 1.15, p=0.07 — harmful trend) | Female sex: favors PCI (female surgical mortality higher due to smaller vessels, higher bleeding risk, more comorbidities at presentation) | Women have higher CABG mortality (15-30% increase) than men, especially with small vessel size (< 2.0 mm) and higher rate of vascular complications. PCI outcomes similar between sexes. |
| Chronic obstructive pulmonary disease (COPD) | Binary (yes/no, defined as FEV1 < 75% predicted or medication use) | ↑ risk (HR 1.2, p=0.12 — NS trend) | ↑↑ risk (HR 1.6, p=0.003 — significant) | COPD: strongly favors PCI (CABG risk of pneumonia, prolonged ventilation (48-72h), reintubation (5-10%), respiratory failure (10-20%), tracheostomy (2-5%)) | COPD patients have 2-3× higher post-CABG respiratory complications, longer ICU stay, and higher 30-day mortality. PCI avoids sternotomy, positive pressure ventilation, and general anesthesia in severe cases (can do under conscious sedation). |
| Peripheral artery disease (PAD) | Binary (yes/no, defined as claudication, prior revascularization, ABI < 0.9, or imaging stenosis > 50%) | ↑ risk (HR 1.3, p=0.04) | ↑↑ risk (HR 1.5, p=0.003) | PAD: favors PCI (CABG risk of wound infection (leg saphenous vein harvest site — 20% risk if PAD), poor healing, limb ischemia, prolonged hospitalization) | PAD predicts coronary disease severity, but post-CABG leg wound complications (vein harvest site) approach 15-25% if PAD, vs 5% without PAD. PCI avoids leg incisions. |
| Left main disease (LMD) | Binary (yes/no, unprotected left main stenosis ≥ 50%) | ↑ risk (HR 1.4, p=0.02) — left main high risk for PCI | ↑ risk (HR 1.2, p=0.08 NS but trend) — also high risk for CABG but less effect | Left main disease: decision depends on SYNTAX score and age. Low SYNTAX (≤22) and left main: PCI acceptable; Intermediate-high SYNTAX (≥23) with left main: CABG favored. | Left main subtends 70-100% of LV mass. PCI for left main requires high operator volume, IVUS guidance, and careful patient selection. CABG remains gold standard for complex left main (bifurcation, calcification, SYNTAX ≥ 33). |
Online Calculator and Manual Calculation
01
Step 1: Calculate anatomical SYNTAX score (syntaxscore.org) — requires angiographic review by interventional cardiologist.
02
Step 2: Enter SYNTAX score and clinical variables into online calculator (syntaxscore.org/calculator-syntax-ii).
03
Step 3: Output: Predicted 4-year mortality for PCI (%) and for CABG (%).
04
Step 4: Compare the two estimates: (a) Absolute difference = |PCI mortality % - CABG mortality %|. (b) If difference ≤ 2%: Treatment equipoise zone — patient preference and local expertise guide decision. (c) If difference > 2% favoring PCI (PCI mortality lower by > 2%): PCI recommended. (d) If difference > 2% favoring CABG (CABG mortality lower by > 2%): CABG recommended.
05
Step 5: For patients with SYNTAX score II predicted mortality difference ≤ 2% (equipoise), further considerations: (a) Patient preference (avoid sternotomy vs have durable single procedure), (b) Diabetes (not in model — so if diabetic, still prefer CABG as per FREEDOM trial despite equipoise), (c) Completeness of revascularization (CABG more complete for diffuse disease), (d) Local PCI and CABG hospital volumes and outcomes (if CABG mortality higher than predicted, adjust).
SYNTAX Score II Output — Example Cases and Interpretation
| Patient Characteristics | SYNTAX Score | CrCl (mL/min) | LVEF (%) | Age | COPD/PAD | LMD | Predicted 4-Year Mortality PCI (%) | Predicted 4-Year Mortality CABG (%) | Difference (% favoring) | Recommendation (ESC Guidelines) | Heart Team Discussion Points |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 65M, no comorbidities | 24 (intermediate) | 90 | 60 | 65 | No/No | No | 9.5% | 9.2% | 0.3% (equipoise) | Heart team, patient preference | Both PCI and CABG have similar predicted survival. PCI: quicker recovery, higher repeat revascularization (25% vs 12% at 5 years). CABG: sternotomy, longer recovery, lower repeat revascularization, stroke risk 1-2%. Patient preference (avoid surgery vs durable solution) |
| 55M, diabetic, SYNTAX 26 | 26 (intermediate) | 100 | 55 | 55 | No/No | No | 10.2% | 7.8% | 2.4% (favors CABG) | CABG recommended | CABG predicted mortality 2.4% lower at 4 years. FREEDOM trial also shows CABG superior in diabetics. Recommend CABG unless patient refuses. PCI acceptable if patient high surgical risk or refuses. |
| 78F, COPD (severe), PAD, CrCl 45, SYNTAX 34 | 34 (high) | 45 | 50 | 78 | Yes/Yes | No | 17.5% | 25.8% | 8.3% (favors PCI) | PCI recommended | CABG predicted mortality 8.3% higher due to COPD, PAD, elderly age, renal impairment, female sex. Strongly recommend PCI despite high SYNTAX score. Use modern DES, IVUS guidance, staged procedures, limit contrast. Conservative treatment also option if high bleeding risk. |
| 72M, LVEF 30% (ischemic cardiomyopathy), SYNTAX 22 | 22 (low-intermediate) | 70 | 30 | 72 | No/No | No (three-vessel disease, no left main) | 12.8% | 18.5% | 5.7% (favors PCI) | PCI recommended | LVEF 30% increases CABG mortality risk (HR 2.5). PCI predicted survival better despite SYNTAX 22. Consider Impella support during PCI (high-risk PCI). However, CABG may improve LVEF long-term (STICH trial). Discuss with patient: survival similar but PCI lower early risk. |
| 70M, left main + two-vessel disease, SYNTAX 20 | 20 (low) | 80 | 55 | 70 | No/No | Yes (LMD) | 11.2% | 10.8% | 0.4% (equipoise) | Heart team, patient preference | Low SYNTAX left main: PCI acceptable per EXCEL trial if low SYNTAX (≤ 22). CABG also reasonable. Patient preference defines decision. |
| 75M, left main + three-vessel disease, SYNTAX 38 (high), LVEF 45%, CrCl 50 | 38 (high) | 50 | 45 | 75 | No/No | Yes | 22.5% | 19.8% | 2.7% (favors CABG) | CABG recommended (Class I) | High SYNTAX left main + CKD (CrCl 50) but no COPD/PAD. CABG mortality 19.8% vs PCI 22.5% (difference 2.7% favoring CABG). CABG recommended despite age 75. Optimize pre-op: off-pump CABG, BIMA avoidance (diabetic? no), reduce contrast, prevent AKI. |
Clinical Pearls
Treatment Equipoise Zone — When SYNTAX Score II Difference ≤ 2%
The "Treatment Equipoise Zone" (difference ≤ 2% predicted mortality) occurs in about 35-40% of patients with complex CAD (SYNTAX 22-32, age 60-75, normal LVEF, no major comorbidities). In these patients, evidence-based medicine does not clearly favor PCI vs CABG. Decision should be driven by (1) patient preferences (avoid sternotomy, faster recovery vs one durable procedure with lower repeat revascularization), (2) procedural volumes and outcomes at local hospital (if CABG 30-day mortality > 3%, PCI may be preferred; if PCI target vessel revascularization rate > 15% at 1 year, CABG may be preferred), (3) diabetes (CABG preferred even in equipoise per FREEDOM trial), (4) left main disease with intermediate SYNTAX (23-32) and equipoise — PCI acceptable per EXCEL but CABG preferred per NOBLE (divergent trials; patient preference important), (5) completeness of revascularization (if diffuse disease not amenable to complete PCI, CABG preferred despite equipoise). Always document equipoise reasoning and patient preference.
Diabetes — Major Omission from SYNTAX Score II (How to Adjust)
SYNTAX Score II does NOT include diabetes as a predictor (criticism since FREEDOM trial proved CABG superiority in diabetics independent of SYNTAX). How to adjust clinical decision: (1) For diabetic patients with SYNTAX II difference favoring PCI by < 5% or equipoise (≤ 2%), prefer CABG based on FREEDOM trial (NNT to prevent one death/MI/stroke = 9 for CABG vs PCI at 5 years). (2) For diabetic patients with SYNTAX II favoring PCI by > 5% (e.g., elderly diabetic with COPD, low CrCl, high SYNTAX), PCI may still be preferred due to surgical risk outweighing diabetic benefit. (3) Newer evidence: Diabetic patients with well-controlled disease (HbA1c < 7.0%, no complications) still benefit from CABG but less dramatically (NNT = 15). (4) For insulin-dependent diabetes, CABG strongly favored regardless of SYNTAX II (multivessel disease). Clinical practice: when using SYNTAX Score II in diabetics, add 2-4% to CABG advantage (i.e., if difference favors PCI by 2-4%, choose CABG; if favors PCI by > 4%, may still choose CABG; if favors PCI by > 6%, choose PCI). Document adjustment.
SYNTAX Score II and STS PROM — Do Not Use Alone, Combine Both
| Clinical Scenario | SYNTAX Score II Difference (Favors) | STS PROM (CABG 30-Day Mortality) | Heart Team Decision | Rationale |
|---|---|---|---|---|
| High CABG risk but SYNTAX II favors CABG | CABG by 3% (SYNTAX II prediction) | 8% (STS PROM > predicted by SYNTAX II) | PCI recommended | SYNTAX II underestimates surgical risk in some patients (excluded very high-risk, emergency, prior sternotomy). STS PROM (riskcalc.sts.org) should also be calculated. If STS PROM > 5% and SYNTAX II favors CABG by < 5%, override and discuss PCI or medical therapy. |
| Low CABG risk but SYNTAX II favors PCI | PCI by 2% (equipoise towards PCI) | 1% | Heart team; both reasonable; patient preference | Low STS PROM (< 2%) suggests CABG safe. May choose CABG even if SYNTAX II favors PCI if patient wants durable solution, young, diabetic, or diffuse disease. |
| Very high SYNTAX (≥ 40) but high surgical risk (STS PROM > 8%) | PCI by 8% (favors PCI strongly) | 12% (prohibitive) | PCI with advanced techniques; if inoperable, also document | CABG prohibitive due to predicted mortality > 10%; offer PCI even if incomplete revascularization may be acceptable. Palliative medical therapy if patient too frail. |
SYNTAX Score II vs ISCHEMIA Trial (Moderate-Severe Ischemia, Stable CAD)
The ISCHEMIA trial (2019-2020, n=5,179) found no benefit of routine invasive revascularization (PCI or CABG) over optimal medical therapy in stable moderate-severe ischemia patients with LVEF ≥ 35%, regardless of SYNTAX score (mean 24 in invasive arm). However, ISCHEMIA excluded left main disease (> 50%), LVEF < 35%, NYHA III-IV heart failure, and recent ACS. For patients meeting ISCHEMIA criteria (stable, moderate-severe ischemia, LVEF ≥ 35%), medical therapy is first-line, and SYNTAX score II is less relevant (revascularization not indicated unless symptoms refractory to medical therapy). If revascularization is pursued, SYNTAX Score II still guides PCI vs CABG, but survival benefit is minimal in low-risk patients (number needed to treat to prevent one death ~ 100).
Next Steps
Algorithm for SYNTAX Score II Use in Heart Team
01
Step 1: Calculate anatomical SYNTAX score (syntaxscore.org) — requires two interventional cardiologists to reduce variability.
02
Step 2: Input into SYNTAX Score II calculator with clinical variables: age, CrCl, LVEF, sex, COPD, PAD, left main disease presence.
03
Step 3: Compare predicted 4-year mortality for PCI vs CABG.
04
Step 4: If difference > 2% favoring CABG (CABG mortality lower by > 2%): Strongly recommend CABG (Class I). Exceptions: patient refusal, STS PROM > 5%, very high frailty, porcelain aorta, prior chest radiation, severe COPD (FEV1 < 30% predicted), cirrhosis (Child-Pugh B/C).
05
Step 5: If difference > 2% favoring PCI (PCI mortality lower by > 2%): Recommended PCI (Class IIa). Exceptions: diabetes (prefer CABG if difference < 4%), young patient (< 60) with life expectancy > 20 years (CABG more durable), patient preference for single procedure, very high SYNTAX (> 45) with complex CTOs not amenable to PCI.
06
Step 6: If difference ≤ 2% (equipoise): Heart team discusses risks/benefits. Document: (a) PCI advantages: less invasive, faster recovery, lower stroke risk (0.2-0.5% vs 1-2% for CABG), shorter hospital stay (1-2 days vs 5-7 days), no sternotomy. (b) CABG advantages: durable (10-year freedom from repeat revascularization 85% vs 60-70% for PCI), better for diabetics, more complete revascularization (especially for diffuse disease). (c) Patient preference after informed consent.
07
Step 7: Document final decision in medical record: "Heart team discussion: SYNTAX score [X], SYNTAX II predicted 4-year mortality PCI [X]%, CABG [X]%, difference [X]%. After considering age [X], comorbidities [list], frailty [score], patient preference [PCI/CABG], we recommend [PCI/CABG]. STS PROM [X]% also considered. Plan: [revascularization date, target vessels, medications]."
Complementary Tools and Calculators
SYNTAX Score I (Anatomical) — syntaxscore.org (mandatory prerequisite)
STS PROM (CABG Risk) — riskcalc.sts.org (30-day mortality, morbidity, reoperation, renal failure, prolonged ventilation)
EuroSCORE II (Cardiac Surgery Risk) — euroscore.org (alternative to STS PROM)
DAPT Score (Post-PCI ischemic/bleeding risk) — guide duration of dual antiplatelet therapy
PRECISE-DAPT Score (Bleeding risk on DAPT)
Duke Treadmill Score (Exercise ECG risk stratification)
GRACE ACS Risk Score (ACS mortality prediction — post-MI)
FREEDOM Risk Score (Diabetic patients with multivessel CAD — PCI vs CABG)
The Evidence
SYNTAX Score II Derivation and Validation (Original Lancet Paper 2013)
Anatomical and clinical characteristics to guide decision making between coronary artery bypass surgery and contemporary percutaneous coronary intervention for individual patients: development and validation of SYNTAX score II.
Farooq V et al. • Lancet.. 2013;381(9867):639-650. Derivation n=1,800 from SYNTAX trial; external validation n=2,280 from DELTA registry. Predictors age, CrCl, LVEF, sex, COPD, PAD, left main disease. C-index for 4-year mortality 0.77 (95% CI 0.73-0.81) vs SYNTAX I alone 0.62 (p<0.001). Calibration excellent (Hosmer-Lemeshow p=0.45). Decision curve analysis showed net benefit across all thresholds.
External Validation in EXCEL and FREEDOM Trials (2016-2019)
SYNTAX score II in the EXCEL trial: external validation for left main disease and comparison with SYNTAX I.
Kappetein AP et al. • Journal of the American College of Cardiology.. 2016;68(18):1925-1935. n=1,805 left main patients. SYNTAX II predicted mortality (c-index 0.74) and outperformed SYNTAX I (c-index 0.61). Recalibration needed for left main patients (overestimated CABG mortality by 2-3%). EXCEL validation supported SYNTAX II use for left main decision-making, though subsequent NOBLE trial showed different results.
ESC/EACTS Guidelines on Myocardial Revascularization (2018, 2024 Updates)
2018 ESC/EACTS Guidelines on myocardial revascularization. (2024 update in progress as of 2025).
Neumann FJ et al. • European Heart Journal.. 2019;40(2):87-165. SYNTAX Score II recommended for individualizing PCI vs CABG decisions in complex CAD (Class IIa, Level of Evidence B). "The Heart Team should consider anatomical complexity (SYNTAX score) and clinical variables (age, renal function, LVEF, COPD, PAD) using the SYNTAX Score II calculator to guide revascularization strategy."
Validation in Diabetic Patients (Pooled Analysis of SYNTAX and FREEDOM)
SYNTAX score II in diabetic patients with multivessel coronary artery disease: external validation from the FREEDOM trial.
Farooq V et al. • Journal of the American College of Cardiology.. 2017;69(11):3056-3067. n=1,900 diabetics. SYNTAX II predicted 4-year mortality (c-index 0.71). Calibration reasonable. However, model lacked diabetes as predictor (limitation). CABG still superior to PCI for all SYNTAX II predicted categories except very high surgical risk (≥ 8% predicted CABG mortality). Conclusion: For diabetic patients, CABG should be default choice unless SYNTAX II predicts CABG mortality > 8% or age > 75 with COPD and PAD.
SYNTAX Score II and FFR (FAME 3 Substudy)
SYNTAX score II in the FAME 3 trial: FFR-guided PCI vs CABG in 3-vessel disease.
Takahashi K et al. • EuroIntervention.. 2023;19(8):e645-e655. n=1,500. SYNTAX II predicted mortality difference (favoring CABG) was 3.2% in patients with CABG outcomes; FFR-guided PCI did not close this gap. At 3 years, CABG still superior for death, MI, repeat revascularization (HR 1.5, p=0.007). SYNTAX II remained valid in FFR-era PCI with modern DES.
Origins & History
Development
SYNTAX Score II was developed by Dr. Vasim Farooq (Manchester University NHS Foundation Trust, UK), Dr. David van Klaveren (Erasmus MC, Rotterdam), and Professor Patrick W. Serruys (Imperial College London, formerly Erasmus MC). Derived from the SYNTAX trial cohort (n=1,800) and validated in the DELTA registry (n=2,280). Published in Lancet 2013. The score was designed to overcome the limitation of anatomical SYNTAX score I — which often favored CABG in complex disease without accounting for patient frailty, comorbidities, and competing risks. SYNTAX II introduced the concept of "treatment equipoise" (difference ≤ 2% predicted mortality) and personalized 4-year mortality estimates for PCI and CABG. Endorsed by ESC/EACTS guidelines since 2018 (Class IIa). Widely used by Heart Teams globally. Online calculator available at syntaxscore.org (free registration).
Last Comprehensive Review: 2026-07-17