The association between whole blood viscosity and high thrombus burden in patients with non-ST elevation myocardial infarction

BACKGROUND: Prior studies showed that patients with elevated whole blood viscosity (WBV) had a higher risk of arterial thrombosis, acute stent thrombosis, and left ventricular apical thrombus presence after acute coronary syndrome. This investigation aimed to determine the association between WBV and high thrombus burden (HTB) in non-ST elevation myocardial infarction (NSTEMI) patients treated with percutaneous coronary intervention (PCI). METHODS: This retrospective cohort investigation included data from consecutive 290 NSTEMI patients who received PCI at a tertiary institution. Patients with grade 1-3 thrombus burden were categorized as having low thrombus burden (LTB) (n = 178), whereas those with grade 4-5 thrombus burden were classified as having HTB (n = 112). WBV at high shear rate (HSR) and low shear rate (LSR) were estimated using hematocrit (HTC) and total protein levels. RESULTS: Patients with HTB had higher WBV at both LSR and HSR. In HTB patients, the frequency of infarct-related artery (IRA) reference vessel diameter, distal embolization, and no-reflow was also higher. Multivariable logistic regression models indicated that WBV at LSR (odds ratio [OR], 1.028; 95% confidence interval [CI], 1.014-1.043; P < 0.001) and HSR (OR, 1.606; 95% CI, 1.334-1.953; P < 0.001) were independent predictors of HTB in NSTEMI patients. Notably, the area under the curve value of WBV at both shear rates was greater than that of its components, including total protein and HTC. CONCLUSION: This is the first study showing that WBV at both shear rates is a significant predictor of HTB in NSTEMI patients.