Journal of Geriatric Cardiology (2011) 8: 3134 ©2011 IGC All rights reserved; www.jgc301.com Research Articles Medical comorbidities at admission is predictive for 30-day in-hospital mortality in patients with acute myocardial infarction: analysis of 5161 cases  Open Access  Xue-Dong Yang, Yu-Sheng Zhao, Yu-Feng Li, Xin-Hong Guo Institute of Geriatric Cardiology, Chinese PLA General Hospital, Beijing 100853, China Abstract Background The present study investigated the prognostic value of medical comorbidities at admission for 30-day in-hospital mortality in patients with acute myocardial infarction (AMI). Methods A total of 5161 patients with AMI were admitted in Chinese PLA General Hospital between January 1, 1993 and December 31, 2007. Medical comorbidities including hypertension, diabetes mellitus, previous myocardial infarction, valvular heart disease, chronic obstructive pulmonary disease (COPD), renal insufficiency, previous stroke, atrial fibrillation and anemia, were identified at admission. The patients were divided into 4 groups based on the number of medical comorbidities at admission (0, 1, 2, and ≥ 3). Cox regression analysis was used to calculate relative risk (RR) and 95% confidence intervals (CI), with adjustment for age, sex, heart failure and percutaneous coronary intervention (PCI). Results The mean age of the studied population was 63.9 ± 13.6 years, and 80.1% of the patients were male. In 74.6% of the patients at least one comorbidity were identified. Hypertension (50.7%), diabetes mellitus (24.0%) and previous myocardial infarction (12%) were the leading common comorbidities at admission. The 30-day in-hospital mortality in patients with 0, 1, 2, and ≥ 3 comorbidities at admission (7.2%) was 4.9%, 7.2%, 11.1%, and 20.3%, respectively. The presence of 2 or more comorbidities was associated with higher 30-day in-hospital mortality compared with patients without comorbidity (RR: 1.41, 95% CI: 1.13-1.77, P = 0.003, and RR: 1.95, 95% CI: 1.59-2.39, P = 0.000, respectively). Conclusions Medical comorbidities were frequently found in patients with AMI. AMI patients with more comorbidities had a higher 30-day in-hospital mortality might be predictive of early poor outcome in patients with AMI. J Geriatr Cardiol 2011; 8: 3134. doi: 10.3724/SP.J.1263.2011.00031 Keywords: acute myocardial infarction; comorbidity; mortality 1 Introduction In the past five decades, we have witnessed major breakthroughs in the management of acute myocardial infarction (AMI).[1] However, AMI remains a leading cause of death worldwide, and the mortality rate from AMI is still unacceptably high.[2,3] Many challenges remain in the risk stratification and management of patients with AMI, such as optimal risk stratification of patients, with comorbidities. Comorbidities may affect multiple clinical outcomes, including mortality, quality of life, and cost.[4] Comorbidities in patients with AMI, such as renal insufficiency, diabetes mellitus and stroke, may reduce the patient’s physiologic reserve and thereby increase the risk of adverse outcome. Therefore the assessment of comorbidity is important for Correspondence to: Yu-Sheng Zhao, MD, Institute of Geriatric Cardiology, Chinese PLA General Hospital, Fuxing Road 28, Beijing 100853, China. E-mail: zys3012002@yahoo.com Telephone: +86-10-55499139 Fax: +86-10-68188906 Received: September 5, 2010 Revised: March 17, 2011 Accepted: March 24, 2011 Published online: March 28, 2011 risk stratification of AMI. To date, little information is available on the effects of patients’ comorbidity on the outcome of patients with AMI. In the present study, we investigated whether medical comorbidities at admission might be predictive for the 30-day in-hospital mortality of patients with AMI hospitalized in a single medical center. 2 2.1 Methods Data sources Since 1992 a computerized medical record database has been established in the Chinese PLA General Hospital, with the diagnostic codes based on the ninth revision of the International Classification of Diseases developed by the World Health Organization, commonly referred to as ICD9. The medical records of the patients with a primary diagnosis of AMI who were admitted between January 1, 1993 and December 31, 2007 were identified through discharge diagnosis of ICD9 code 410. A total of 5161 patients were identified, and the medical records of these patients were then reviewed, with emphasis on age, gender, medical http://www.jgc301.com; jgc@mail.sciencep.com | Journal of Geriatric Cardiology