Validity of Charlson Comorbidity Index in Patients Hospitalized With Acute Coronary Syndrome. Insights From the Nationwide AMIS Plus Registry 2002–2012
Does the Charlson Comorbidity Index (CCI) predict in-hospital and 1-year follow-up mortality for patients with acute coronary syndrome (ACS)?
The AMIS Plus Registry, a nationwide prospective registry of patients admitted with ACS to hospitals (n = 69) in Switzerland, founded in 1997, was used for the present analysis. Participating centers were strongly encouraged to enroll all patients fulfilling the inclusion criteria to avoid selection bias. Hospital data were provided and completed by the treating physician or a trained study nurse. Between 2002 and 2012, 30,711 patients with ACS were enrolled in the AMIS Plus Registry. Comorbidities were unknown for 1,091 (3.6%) patients. Complete data on comorbidities were available from 29,620 patients. The main outcome measures were in-hospital and 1-year follow-up mortality.
A total of 29,620 ACS patients were included in the study population, of which 27% were women (mean age 72.1 ± 12.6 years) and 73% were men (64.2 ± 12.9 years). Of these patients, 46.8% had comorbidities and they were less likely to receive guideline-recommended drug therapy and reperfusion. Past history of myocardial infarction (MI) was the most frequent comorbidity (18.0%), followed by diabetes mellitus (14.7%), moderate to severe renal disease (7.1%), cerebrovascular disease (6.0%), and chronic lung disease (6.0%). Heart failure (adjusted odds ratio [OR], 1.88; 95% confidence interval [CI], 1.57-2.25), metastatic tumors (OR, 2.25; 95% CI, 1.60-3.19), renal diseases (OR, 1.84; 95% CI, 1.60-2.11), and diabetes (OR, 1.35; 95% CI, 1.19-1.54) were strong predictors of in-hospital mortality. In this population, CCI weighted the history of prior MI higher (1 instead of −0.4; 95% CI, −1.2 to 0.3 points), but heart failure (1 instead of 3.7; 95% CI, 2.6-4.7) and renal disease (2 instead of 3.5; 95% CI, 2.7-4.4) lower than the benchmark, where all comorbidities, age, and gender were used as predictors. However, the model with CCI and age had an identical discrimination to this benchmark (areas under the receiver operating characteristic curves were both 0.76).
The investigators concluded that comorbidities greatly influenced clinical presentation, therapies received, and the outcome of patients admitted with ACS. Heart failure, diabetes, renal disease, or metastatic tumors had a major impact on mortality. They also concluded that CCI seemed to be an appropriate prognostic indicator for in-hospital and 1-year outcomes in ACS patients.
Use of tools that identify patients at high risk of death over a 1-year period can be clinically informative when patients and their health providers are making management decisions. Further evaluation of this index in other populations is warranted.
Keywords: Outcome Assessment (Health Care), Myocardial Infarction, Acute Coronary Syndrome, Neoplasms, Hospital Mortality, Heart Failure, Comorbidity, Switzerland, Diabetes Mellitus, Lung Diseases
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