Thromboelastography-based assessment of thrombus burden in STEMI

Thrombus formation in coronary arteries is a crucial pathophysiological event in ST-elevation myocardial infarction (STEMI). High thrombus burden is an independent predictor of percutaneous coronary intervention (PCI) failure and no-reflow in patients with STEMI. Traditional monitoring of anticoagulation during primary PCI using activated clotting time (ACT) has limitations. Thromboelastography (TEG), a dynamic point-of-care test, offers comprehensive assessment of hemostatic function and may better reflect thrombus burden.

To evaluate the utility of TEG-derived parameters in assessing coronary thrombus burden and coagulation status in STEMI patients undergoing PPCI.

This cross-sectional study enrolled 81 consecutive STEMI patients at a tertiary care center. TEG analysis including reaction time (R-time), K-time, α-angle, maximum amplitude (MA), clotting index (CI), and lysis at 30 minutes (LY30) was performed alongside angiographic grading of thrombus burden (Grades 0–V). Statistical association between TEG parameters and thrombus grade was analyzed.

Mean age was 55.2 ± 10.6 years; 87.7% were male. Anterior wall MI predominated (74.1%). Significant cardiovascular risk factors included smoking (55.6%) and dyslipidemia (54.3%). TEG showed mean R-time of 4.9 ± 3.7 min, α-angle 64.1° ± 13.7, MA 62.8 ± 12.0 mm, and CI 2.4 ± 1.8. Among TEG parameters, α-angle demonstrated a significant association with thrombus grade (p = 0.01), increasing with higher thrombus burden. R-time showed a non-significant trend toward shorter times with higher thrombus grade (p = 0.09). MA, CI, and G values were higher in severe thrombus grades but without statistical significance. Ly30 was negligible in most patients. Comparing high thrombus burden (grades IV and V) to low thrombus burden (grades 0-III), the K Min and R Min parameters exhibited high specificity (85.7% and 96.4%) and positive predictive values (75% and 85.7%), resulting in a diagnostic gain of +14 and +23 over baseline prevalence. Sensitivity was low for these parameters. Other TEG indices displayed moderate or no diagnostic utility.

TEG, especially alpha angle, K Min, and R Min, provides valuable diagnostic insight for thrombus burden in STEMI, with K Min and R Min serving as potential 'rule-in' tests for significant thrombus. It holds promise for enhancing individualized anticoagulation strategies during PPCI. Larger, prospective studies are warranted to validate these findings and assess the prognostic significance of TEG in STEMI management.

ATEG parameters and coronary thrombus