# Prognostic significance of residual functional SYNTAX score II in acute myocardial infarction

## TL;DR

This study shows that a new score combining blood flow measurements and risk factors can better predict heart problems in patients who had a heart attack and a procedure to open blocked arteries.

## Contribution

The study introduces and validates the rFSS-II score, which integrates QFR and clinical factors for improved prognosis prediction in AMI patients post-PCI.

## Key findings

- High rFSS-II patients had significantly higher MACE incidence (55.7% vs. 18.1%) over 3 years.
- rFSS-II outperformed traditional risk scores in predicting adverse cardiac events.
- rFSS-II was an independent predictor of MACE with a hazard ratio of 1.08 per unit increase.

## Abstract

The residual functional SYNTAX (Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) score (rFSS) predicts patient prognosis post-percutaneous coronary intervention (PCI). We aimed to integrate rFSS with clinical risk factors (rFSS-II) to comprehensively assess patient prognosis, guided by the quantitative flow ratio (QFR), and compare its predictive efficacy with other scoring systems.

We enrolled 175 acute myocardial infarction (AMI) patients undergoing post-PCI physiological measurements. Three distinct models were established based on different calculation methods of rFSS-II, and their respective abilities to predict major adverse cardiac events (MACE) were evaluated. Patients were categorized into high rFSS-II (n = 70) and low rFSS-II (n = 105) groups. The MACE incidence was compared between these groups over a 3-year follow-up period, using multivariable Cox regression analysis to identify MACE predictors.

High rFSS-II patients had more MACE than low rFSS-II patients (55.7% vs. 18.1%; p < 0.001). The rFSS-II model had higher accuracy than other traditional risk scores, except for rSS-II. In a multivariable-adjusted model, rFSS-II emerged as an independent predictor of MACE (adjusted hazard ratio: 1.08 per 1 unit increase, 95% confidence interval [CI]: 1.05–1.11, p < 0.001).

QFR-guided rFSS-II proved to have good predictive value among AMI patients 3 years post-PCI. Calculating the total score of all vascular segments with QFR ≤ 0.80 may provide enhanced predictive capability.