Prognostic Impact Of Anemia On Undergoing Percutaneous Coronary Intervention In Patients With Acute ST-segment Elevation Myocardial Infarction

Objectives: This study was to explore prognostic impact of differenthematocrit levels on patients with acute ST-segment elevation myocardialinfarction undergoing percutaneous coronary intervention.Methods: From February2011to February2012, a total of158consecutive patients (male91cases, female67cases) who suffered fromSTEMI within24hours from symptom onset and treated with emergency PCIwere enrolled into this study. The STEMI was defined according to theguideline of ACC/AHA as electrocardiographic (ECG) ST-segment elevationat least two contiguous leads and elevated serum markers of myocardialnecrosis greater than twice the upper limit for creatine kinase or troponinswith symptoms compatible with AMI for more than30minutes. Exclusioncriteria were including major surgery, trauma and bleeding history within3months, contraindications of anticoagulation and antiplatelet therapy,hemorrhagic cerebrovascular accident or ischemic cerebral vascular accidentwithin six months, presence of bleeding disorder thrombocytopenia, allergy toaspirin and contrast agent, severe hepatic and renal damage, as well asmalignancy. Venous blood samples were examined within6hours afteradmission, and patients were divided into3groups according to hematocrit(Hct) levels: group A (severe anemia group, n=28, Hct≤0.33), group B(mild anemia group, n=68,0.33<Hct≤0.39), group C (no anemia group,n=62,0.39<Hct≤0.55). All patients underwent primary percutaneouscoronary intervention on admission, and the quantitative coronary analysis(QCA) was used to measure the characteristics of IRA. Stents were implantedif the stenosis of IRA was more than75%. PCI procedures were recordedincluding coronary artery lesions, coronary lesion types, the infarct-related artery (IRA), TIMI grade after stent implantation. The basic clinical data ofpatients admitted to hospital within24h were also recorded, including age, sex,weight, height, fasting glucose, triglycerides, low-density lipoprotein, highdensity lipoprotein values and history indicators. Echocardiography was usedto measure left ventricular end-diastolic volume (left ventricular end diastolicvolume, LVEDV) and left ventricular ejection fraction (left ventricularejection fraction, LVEF). Wall motion score index (wall motion score index,WMSI) was analyzed. Patients were followed up30days and one year afterPCI, and MACE (cardiac death, nonfatal acute myocardial infarction, targetvessel revascularization) were evaluated among the three groups. Aspirin,clopidogrel, low molecular heparin, ACEI, beta blockers, statins and otherdrugs were used to all patients. All data were analyzed by use of the SPSS13.0package, and P value <0.05was considered statistically significant.Results:1Comparison of basic clinical dataThere were significant differences in clinical data which was includingage, gender, body mass index, serum creatinine, triglycerides, low-densitylipoprotein, left ventricular ejection fraction and white blood cell count (P<0.05). The level of age, creatinine and white blood cell count were higher ingroup A and group B than those in group C. The proportion of women ishigher in group A. The level of low density lipoprotein and LVEF was higherin group B and group C than those in group A. The level of triglycerides waslower in group A than those in group C. There were no significant differencesin clinical data which was including systolic blood pressure, diastolic bloodpressure, blood sugar and high-density lipoprotein(P>0.05). History of thecomparison: There were no significant differences in history which wasincluding hypertension, myocardial infarction, revascularization (P>0.05).There were significant differences in history which was including diabetes,obsolete cerebral infarction and chronic renal insufficiency (P<0.05). Thepatients in group A have more diabetes, old cerebral infarction and chronicrenal insufficiency than those in group B and group C. There were no significant differences in medication which was including aspirin, angiotensinconverting enzyme inhibitors, beta blockers and statins (P>0.05).2Comparison of the results of coronary angiography and PCINo significant differences were found in coronary artery lesions,coronary lesion type, and the number of stents among three groups. Nosignificant differences were found in TIMI flow grade before and after PCIand infarct-related artery among the three groups.3Comparison of the three groups in left ventricular function indicatorsThe level of LVEF was lower in group A than those in group C (49.5%vs.53.5%, P=0.0083). The level of WMSI was higher in group A than those ingroup B (2.6vs.2.2, P<0.01). The level of WMSI was higher in group A thanthose in group C (2.6vs.2.1, P<0.01). The level of LVEDV was higher ingroup A than those in group B (164.4ml vs.138.5ml, P=0.0011). The level ofLVEDV was higher in group A than those in group C (164.4ml vs.127.6ml,P<0.0001).4The incidence of MACE after PCIAfter30days：There were no significant differences in MACE which wasincluding cardiac mortality, nonfatal myocardial reinfarction rate and targetvessel revascularization rate.One year after PCI： There were significant differences in cardiacmortality (P=0.019). The mortality in group A was higher compared withgroup C (14.3%vs.1.6%, P=0.031). There were significant differences inmyocardial reinfarction rate among the three groups (P=0.025). Themyocardial reinfarction rate in group A was higher than that in group C(21.4%vs.3.2%, P=0.010). The level of target vessel revascularization ratesin the three groups were similar. There were significant differences in MACEamong three groups during one year follow-up (P=0.008). There weresignificant differences between Group A and group B (46.4%vs.23.5%,P=0.026). There were also significant differences in group A and group C(46.4%vs.16.1%, P=0.003).5MACE in hematocrit After controlling for multiple covariates, we found that hematocrit is nota predictor of MACE follow-up of30days. There were no significantdifferences by Log-Rank test in the MACE incidence follow-up of30days (P=0.645). Hematocrit is an independent predictor of the incidence of MACEone year after PCI (OR,0.002,95%CI0.000~0.822). There were significantdifferences in the incidence of MACE one year after PCI by Log-Rank test(P=0.007).Conclusions:1Anemia had no impact on the TIMI flow grade in patients with STEMIundergoing PCI.2The cardiac function in STEMI patients with anemia was worse thanthat of patients with no anemia after PCI.3The incidence of MACE in STEMI patients with severe anemia ishigher than that of patients with no anemia after PCI, and anemia is anindependent predictor of the MACE after PCI.