Relationship between blood viscosity and thrombus burden in ST-segment elevation myocardial infarction

BACKGROUND:.Increased whole blood viscosity (WBV) is associated with increased infarct area, impaired microvascular circulation and mortality in patients with ST-elevation myocardial infarction (STEMI). OBJECTIVES: We aimed to analyze the association between the WBV and thrombus burden (TB) in STEMI patients. METHODS: This cross-sectional study included 167 STEMI patients who received primary percutaneous coronary intervention. WBV values were assessed using hematocrit and total protein values, and low shear rate(LSR) and high shear rate(HSR) were calculated. Angiographic TB was assessed according to the definition of the Thrombolysis in Myocardial Infarction (TIMI) study group. The cases were dichotomized into low TB (grade 1-3) (n = 87) and high TB (grade 4-5) (n = 80) groups. RESULTS: The mean HSR and LSR values of the high TB group were significantly increased compared to the low TB group (p < 0.001, for each). In ROC analysis,for prediction of TB, a cut-off value of 3.83 WBV for HSR had a 71% sensitivity and a 60.7% specificity, and a cut-off value of 21 WBV for LSR had a 70% sensitivity and 59.9% specificity (p < 0.001,for each). Multivariate regression analysis showed that both HSR (OR = 2.408;p=0.020) and LSR (OR = 1.055;p=0.021) were independent predictors for high TB. CONCLUSION:.Increased WBV was an independent predictor for the presence of high TB in patients with STEMI.

Automated summary

Increased whole blood viscosity is associated with higher thrombus burden in patients with ST-elevation myocardial infarction. High shear rate and low shear rate values were significantly higher in the high thrombus burden group, with specific cut-off values showing good sensitivity and specificity for predicting thrombus burden. Multivariate regression analysis indicated that both high shear rate and low shear rate were independent predictors for high thrombus burden.