Residual SYNTAX Score Calculator – Incomplete Coronary Revascularization

Clinical calculation support · Verify results before clinical use

Post-PCI Residual Disease Assessment

Enter the SYNTAX score for each qualifying untreated lesion identified on the post-PCI angiogram.

0.00Residual score

Residual coronary lesions

Include each residual lesion with visual diameter stenosis ≥50% in a vessel ≥1.5 mm. Obtain each lesion score using the original SYNTAX Score algorithm; enter the resulting lesion score below. Do not enter lesions successfully treated by PCI.

Scoring note: The rSS is the sum of individual SYNTAX scores for all qualifying residual lesions. This page performs the summation; it does not reproduce the full lesion-morphology scoring engine. Use the official SYNTAX Score calculator for lesion-level scoring.

Optional: baseline SYNTAX Score

Enter the pre-PCI baseline SYNTAX Score to calculate the SYNTAX Revascularization Index (SRI). Leave blank if unavailable.

Baseline SYNTAX Score

SRI = [1 − (rSS / baseline SYNTAX Score)] × 100. This is a derived measure of the proportion of baseline anatomical disease burden removed; interpret cautiously if baseline and residual scores were not calculated consistently.

0.00Residual SS

Residual SYNTAX Score category

No residual score entered

Add the residual lesion score(s), then calculate.

Residual lesions entered0

SYNTAX Revascularization Index—

Clinical interpretation

The result will be displayed after calculation. rSS is an anatomical measure and does not establish the functional significance of residual lesions.

About the Residual SYNTAX Score

The residual SYNTAX Score (rSS) quantifies the extent and anatomical complexity of coronary artery disease remaining after percutaneous coronary intervention (PCI). It is calculated by reassessing the post-procedural angiogram and summing the SYNTAX scores of untreated qualifying lesions.

Each lesion with visual diameter stenosis ≥50% in a vessel with reference diameter ≥1.5 mm is eligible for scoring. The original SYNTAX algorithm accounts for coronary segment location and lesion characteristics; the lesion score should be determined with the validated scoring method rather than estimated.

Interpretation used in clinical studies

rSS	Study grouping	Meaning
0	Complete revascularization	No qualifying residual anatomical lesion
>0 to ≤8	Reasonable incomplete revascularization	Residual anatomical disease burden in the lower study-defined range
>8	Incomplete revascularization	Greater residual anatomical disease burden

Important methodological points

Assess both left and right coronary systems and use the post-PCI angiogram.
Do not score lesions below the ≥50% stenosis threshold or in vessels smaller than 1.5 mm.
Serial stenoses less than three vessel reference diameters apart are treated as one lesion in the official SYNTAX definitions; more distant stenoses are separate lesions.
rSS = 0 is an anatomical definition of complete revascularization, not proof of absence of ischemia.
The rSS >8 threshold is a study-derived prognostic grouping, not a universal mandate for repeat revascularization.

References

Farooq V, Serruys PW, Bourantas CV, et al.Quantification of incomplete revascularization and its association with five-year mortality in the SYNTAX trial: validation of the residual SYNTAX score. Circulation. 2013;128(2):141–151. DOI: 10.1161/CIRCULATIONAHA.113.001803.

Généreux P, Palmerini T, Caixeta A, et al.Quantification and impact of untreated coronary artery disease after percutaneous coronary intervention: the residual SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) Score. J Am Coll Cardiol. 2012;59(24):2165–2174. DOI: 10.1016/j.jacc.2012.03.010.

Song Y, Gao Z, Tang X, et al.Impact of residual SYNTAX score on clinical outcomes after incomplete revascularisation percutaneous coronary intervention: a large single-centre study. EuroIntervention. 2017;13(10):1185–1193. DOI: 10.4244/EIJ-D-17-00132.

Sianos G, Morel MA, Kappetein AP, et al.The SYNTAX Score: an angiographic tool grading the complexity of coronary artery disease. EuroIntervention. 2005;1(2):219–227. PubMed record.

Official SYNTAX Score Task Force.SYNTAX Score definitions and lesion eligibility criteria. Official tutorial · Official calculator website.

Clinical disclaimer: This tool supports anatomical quantification after PCI and is not a substitute for angiographic review, physiological assessment (e.g., FFR/iFR when appropriate), Heart Team discussion, or clinical judgement. Prognostic associations reported for rSS categories do not establish an individual patient's absolute risk or determine whether further revascularization is indicated. Ensure baseline and post-PCI scores are assessed consistently by appropriately trained readers.