Relationship Between Admission Clinical Charicteristics And Poor Outcome During Hospitalization Among Acute Myocardial Infarction Patients

BackgroundAcute myocardial infarction (AMI) is most serious cardiovascular disease with high fatality and disability rates. Research works has been focused on risk factors of prognosis for AMI in clinical medicine. It has been generally acknowledged that prognosis especially in acute-stage of AMI patients is closely related to admission clinical charicteristics. However, there have been few reports about relationship between admission clinical charicteristics and poor clinical outcomes (death and severe heart failure) in hospitalization among AMI patients in epidemiology. There has been no report about relationship between clustering of risk factors and prognosis during hospitalization among AMI patients.PurposeThe purposes of this study are to investigate relationship between admission clinical charicteristics and poor clinical outcomes (death and severe heart failure) in hospitalization and relationship between clustering of risk factors and prognosis during hospitalization among AMI patients, and to provide clinical epidemiological basis for evaluation about prognosis and control for risk factors in acue phase of myocardial infarction.MethodsA total of 849 AMI patients consecutively hospitalized in the Second Affiliated Hospital of Soochow University from January of 1998 to October of 2010 were selected as study subjects. Trained and qualified investigators collected data on information of demographic characteristics, life style risk factors, admission blood pressure, heart rate, medical history, clinical laboratory tests and study outcomes(death and heart failure ) for all subjects from medical records by using questionnaire. Statistic analysis was conducted by using SPSS16.0 software. Demographic characteristics and clinical charicteristics in different groups of AMI patients were described by a median (interquartile range) and rate (or proportion), and compared by nonparameter test andχ2 test. The associations between various clinical charicteristics and risk factors clustering and poor outcomes in-hospital were analyzed by using multiple logistic model. odds ratios (ORs) and 95% confidence interval (95%CI) were calculated.Results1. Of total 849 study subjects with AMI, 648 were male and 201 were female. There were 269 patients with study outcomes during hospitalization or at discharge, 139 patients (16.5%) died, and 130 patients(15.9%) had heart failure (NYHA≥3 degree).2. There were significantly difference in histories of coronary heart disease, stroke and diabetes among AMI patients with different NYHA. Rates for coronary heart disease histroy, stroke histroy and diabetes histroy were significantly higher in AMI patients with NYHA≥2 degree than in those with NYHA=1(all P<0.05). Systolic blood pressure (SBP)、diastolic blood pressure (DBP)、pulse pressure (PP)、mean artery pressure (MAP) decreased and heart rate(HR), admission blood glucose, serum uric acid(UA), c-reactive protein, white blood cell (WBC) count and percentage of neutrophilic granulocyte increased with increased NYHA. Rates for coronary heart disease histroy, stroke histroy and diabetes histroy were significantly higher in AMI patients with complications than in those without complications.3. In multiple logistic model, DBP, MAP, heart beat, complications, NYHA, admission blood glucose, UA, WBC count and percentage of neutrophilic granulocyte were associated with in-hospital death and NYHA≥3 degree at discharge among AMI patients(all P<0.05).4. Association between different levels of SBP, DBP, MAP, heart beat, admission blood glucose, UA, WBC count and study outcomes were further analyzed by using multiple logistic model.⑴Compared to those aged 50～60 years, patients aged <50、60～69and≥70 years had OR of 0.217、1.749 and 3.618 for in-hospital death, respectively, which indicated that young patients had lower risk and elder patients had higher risk. patients aged <50、 60～69and≥70 years had OR of 0.197、1.426and 3.035 for NYHA≥3 degree at discharge respectively, which showed the same tendency as risk of death.⑵Compared to those with SBP 120-139 mmHg, patients with SBP≥140 mmHg、100-119 mmHg and <100 mmHg had OR of 0.753、1.184 and 5.352(P<0.05) for in-hospital death, respectively, which showed that patients with lower SBP had higher risk of in-hospital death. patients with SBP≥140 mmHg、100-119 mmHg and <100 mmHg had OR of 0.757、1.225 and 4.787 for NYHA≥3 degree at discharge respectively, which showed the same tendency as risk of death.⑶Compared to those with DBP 60～90 mmHg, patients with DBP>90 mmHg had OR of 0.710 for in-hospital death, but not significant(P>0.05). patients with <60 mmHg had OR of 4.575 and 5.346 (P<0.05) for in-hospital death and NYHA≥3 degree at discharge, respectively, which indicated that the patients with much lower admission DBP had higher risk of in-hospital death and NYHA≥3 degree at discharge.⑷Compared to those with PP 40-50 mmHg, patients with PP<40mmHg had OR of 2.458 and 1.927 (P<0.05) for in-hospital death and NYHA≥3 degree at discharge, respectively, which indicated that the patients with much lower admission PP had higher risk of in-hospital death and NYHA≥3 degree at discharge. However, the ORs of in-hospital death and NYHA≥3 degree at discharge associated for PP51-60 mmHg and≥60 mmHg were not significant.⑸Compared to those withMAP 80-90mmHg, patients with MAP 60～79 mmHg and <60 mmHg had OR of 2.575 (P<0.05) and 6.999 (P<0.05) for in-hospital death, respectively, the patients with MAP <60 mmHg had OR of 9.460 for NYHA≥3 degree at discharge, which indicated that the patients with much lower admission MAP had higher risk of in-hospital death and NYHA≥3 degree at discharge. However, the OR of in-hospital death for MAP≥90 mmHg and the ORs of NYHA≥3 degree at discharge associated for MAP≥90 mmHg and 60-79 mmHgwere not significant.⑹Compared to those with HR <70 beats/min, patients with HR≥90 beats/min had OR of 2.576 (P<0.05) and 2.752 (P<0.05) for in-hospital death and NYHA≥3 degree at discharge, respectively, which indicated that there were association between accelerated heart rate and in-hospital death and NYHA≥3 degree at discharge among AMI patients. However, the OR of in-hospital death and NYHA≥3 degree for 70-89 beats/min were not significant.⑺Compared to those with admission blood glucose(stress hyperglycemia)<6.1mmol/L, patients with admission blood glucose with 6.1～6.9mmol/L and≥7.0mmol/L had OR of 3.590 (P<0.05) and 2.495 (P<0.05) for in-hospital death, 4.197 (P<0.05) and 2.61 (P<0.05) 3 for NYHA≥3 degree at discharge,which indicated that there were association between increased admission blood glucose and in-hospital death and NYHA≥3 degree at discharge among AMI patients.⑻Compared to those with WBC count<8.0 x109, patients with WBC count≥10.0 x109 had OR of 2.343 (P<0.05) and 2.116 (P<0.05)for in-hospital death and NYHA≥3 degree at discharge, respectively, the OR of in-hospital death and NYHA≥3 degree for 8.0-10.0 x109 were not significant, which indicated that there were association between increased WBC and in-hospital death and NYHA≥3 degree at discharge among AMI patients.⑼Compared to those with UA<289 umol/L, patients with UA 289~390umol/L had OR of 2.162 (P<0.05) and 2.887(P<0.05) for in-hospital death and NYHA≥3 degree at discharge, respectively, the patients with UA>390umol/L had OR of 3.569 and 3.347 for in-hospital death and NYHA≥3 degree at discharge, respectively, the ORs were all significant.⑽Compared to those without risk factors, patients with 1、2、≥3 risk factors clustering (MAP<60 mmHg, HR≥90 beat/min, admission blood glucose≥6.1mmol/L and WBC≥10.0 x109 ) had OR of 3.101, 5.990 and 12.568 (all P<0.05) for in-hospital death, respectively, and OR of 3.714, 5.990 and 14.816 (all P<0.05) for NYHA≥3 degree at discharge, respectively,which indicated that multiple risk factors clustering would increase the risk in-hospital death and NYHA≥3 degree at discharge.Conclusion1.Among 849 AMI patients included in this study, the rates of in-hospital fatality and NYHA≥3 degree at discharge were 16.5% and 15.9%, respectively.2.Age, complications, heart failure, low blood pressure, accelerated heart rate, increased WBC, high admission blood glucose, and high UA were important clinical charicteristics of AMI ptients with poor clinical outcomes.3.SBP<100mmHg, DBP<60 mmHg, PP<40 mmHg, MAP<60 mmHg,HR≥90 beat/min,admission blood glucose≥6.1mmol/L,WBC≥10.0 x109 and UA≥390umol/L could increase the risk of in-hospital death and NYHA≥3 degree at discharge.4.Clustering of risk factors including MAP<60 mmHg, HR≥90 beat/min, admission blood glucose≥6.1mmol/L and WBC≥10.0 x109 could increase the risks of in-hospital death and NYHA≥3 degree at discharge among AMI patients.