Haemorheological factors and myocardial reperfusion in patients with ST-elevation myocardial infarction undergoing primary coronary intervention.
ABSTRACT The no-reperfusion phenomenon occurs in a considerable number of patients despite restoration of the infarct-related artery (IRA) patency. Factors responsible for this phenomenon include myocardial structural changes, whereas haemorheological parameters that significantly contribute to microvascular resistance, have not been studied so far.
To determine the possible relationship between blood and plasma viscosity, red blood cell aggregation and their deformability, and myocardial reperfusion following effective mechanical intervention of IRA.
The analysis included 23 patients with myocardial infarction treated with primary coronary angioplasty with resultant TIMI (Thrombolysis in Myocardial Infarction) grade 3 flow. Myocardial reperfusion was found effective if myocardial perfusion grade (MPG) was 3. Blood and plasma viscosity were assessed using a Brookfield rotation viscometer. Red blood cell aggregation and deformability were measured with a Laser Optical Rotational Cell Analyzer (LORCA). Patients were divided into two groups with respect to obtained MPG: reperfusion group (14 subjects) and no-reperfusion group (9 patients).
Corrected whole blood viscosity and plasma viscosity were significantly higher in the no-reperfusion group and exceeded the values obtained in the reperfused patients by 14% (p <0.05) and 10.5% (p <0.01), respectively. Red blood cell deformability index at shear stress ranging from 1.75 Pa to 60.03 Pa was significantly lower in the no-reperfusion group. Red blood cell aggregation index was significantly higher (by 14.3%, p <0.05), whereas aggregation halftime was significantly shorter (by 58%, p <0.05) in the no-reperfusion group.
Our results indicate that haemorheological disturbances may be an important factor contributing to no-reperfusion after effective mechanical opening of IRA.
- SourceAvailable from: Francesco Sofi[show abstract] [hide abstract]
ABSTRACT: Previous studies explored the association between hemorheological alterations and acute myocardial infarction, pointing out the role of hematological components on microvascular flow. The aim of this study was to evaluate the association between blood viscosity and infarct size, estimated by creatine kinase (CK) peak activity and cardiac Troponin I (cTnI) peak concentration in ST-segment elevation myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (PCI). The study population included 197 patients with diagnosis of STEMI undergoing PCI. Hemorheological studies were performed by assessing whole blood viscosity (measured at shear rates of 0.512 s(-1) and 94.5 s(-1)) and plasma viscosity using the Rotational Viscosimeter LS 30 and erythrocyte deformability index by Myrenne filtrometer. Significant correlations between CK peak activity, cTnI peak concentration, left ventricular ejection fraction and hemorheological variables were observed. At linear regression analysis (adjusted for age, gender, traditional cardiovascular risk factors, renal dysfunction, timeliness of reperfusion, pre-PCI TIMI flow, infarct location, multivessel disease and previous coronary artery disease) leukocytes and whole blood viscosity at 0.512 s(-1) and 94.5 s(-1) were independently and positively associated with infarct size. These results demonstrate a significant and independent association between hemorheology and infarct size in STEMI patients after PCI suggesting that blood viscosity, in a condition of low flow, might worsen myocardial perfusion leading to an increased infarct size. The measurement of whole blood viscosity in STEMI patients could help to identify those who may benefit from new therapeutic strategies.International journal of cardiology 06/2008; 134(2):189-94. · 7.08 Impact Factor