Combined assessment of fibrinogen-to-platelet ratio and ApoB/ApoA1 ratio for pre-angiographic risk stratification of severe multivessel coronary disease in NSTEMI

Background Residual inflammation and dysregulated lipid metabolism are closely associated with the extent of severe multivessel coronary disease (MVD) in patients with non-ST-segment elevation myocardial infarction (NSTEMI). The fibrinogen-to-platelet ratio (FPR) and the apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) ratio reflect these two residual risk pathways, respectively, whereas the clinical value of their combined assessment for pre-angiographic identification of severe MVD remains to be evaluated. Objective To evaluate the incremental value of combining FPR with the ApoB/ApoA1 ratio for pre-angiographic identification of severe MVD in patients with NSTEMI and to develop an adjunctive risk-stratification model. Methods This single-center retrospective study included 580 patients with NSTEMI who underwent coronary angiography. Correlation analyses, logistic regression, and restricted cubic spline models were used to assess the associations between the two biomarkers and MVD. The area under the receiver operating characteristic curve (AUC), continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to evaluate the incremental value of the biomarkers. A nomogram was developed and internally validated using bootstrap resampling. Decision curve analysis (DCA) was performed to assess net clinical benefit, and subgroup analyses were conducted. Results FPR remained independently and positively associated with severe MVD, with an approximately linear dose-response relationship; the association of the ApoB/ApoA1 ratio was attenuated after full adjustment, although it showed complementary value in patients with a very high coronary lesion burden. With the combined model, the AUC increased from 0.683 to 0.719, while the continuous NRI and IDI were 0.488 and 0.037, respectively; adding the ApoB/ApoA1 ratio to the model containing FPR did not significantly improve the AUC ( P = 0.266) but yielded further improvements in NRI and IDI. Potential effect modification by diabetes status was observed ( P for interaction = 0.025). Conclusion FPR is an important adjunctive biomarker for the pre-angiographic identification of severe MVD in patients with NSTEMI, whereas the ApoB/ApoA1 ratio provides complementary reclassification information. The nomogram incorporating both biomarkers may facilitate pre-angiographic risk stratification.