Coagulation Markers and Myocardial Blush Grade in STEMI: Identifying Potential Predictors of Microvascular Reperfusion

BackgroundMicrovascular reperfusion strongly influences prognosis after ST-elevation myocardial infarction (STEMI). While invasive indices are established, practical non-invasive biomarkers remain limited. This study evaluated whether coagulation markers correlate with myocardial blush grade (MBG)-an angiographic surrogate of tissue-level reperfusion-and could serve as non-invasive indicators of microvascular reperfusion.MethodsIn this single-center case-based study, 48 consecutive STEMI patients undergoing coronary angiography were enrolled. MBG was assessed by an experienced interventional cardiologist blinded to laboratory data. Blood was sampled after reperfusion for tissue plasminogen activator/plasminogen activator inhibitor-1 complex (tPA/PAI), prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex, and D-dimer. Associations between biomarkers and MBG (0-1 vs 2-3) were examined. Receiver operating characteristic (ROC) analysis determined cut-offs; multivariable models evaluated independence.ResultsMean age was 61.2 ± 11.8 years; 87.5% were male. Comorbidities included hypertension (47.9%) and hyperlipidemia (33.3%). MBG distribution was: MBG 3 (33.3%), MBG 1 (25.0%), MBG 0 (22.9%), MBG 2 (18.8%). Patients with MBG 0-1 had significantly higher tPA/PAI and F1 + 2 than those with MBG 2-3 (p = .003 and p < .001, respectively). Admission troponin and CK-MB were also higher in MBG 0-1 (p = .049 and p = .026). ROC analysis showed tPA/PAI < 9.4 μg/dL predicted MBG 2-3 (AUC = 0.752; 95% CI 0.606-0.865; sensitivity 72.0%, specificity 69.57%), and F1 + 2 ≤ 14 580 pmol/L predicted MBG 2-3 (AUC = 0.973; 95% CI 0.880-0.999; p < .001). Lower admission troponin and CK-MB also predicted MBG 2-3. In multivariable analysis, no biomarker remained independently associated with MBG.ConclusionsLower post-reperfusion tPA/PAI and F1 + 2 levels are associated with higher MBG (better microvascular reperfusion) in STEMI. Although not independently predictive, these readily measurable markers-particularly tPA/PAI-may complement reperfusion assessment when direct angiographic evaluation is unavailable. Larger, multicenter studies with standardized sampling are warranted to validate cut-offs and clinical utility.