The association between charlson comorbidity index and mortality in acute coronary syndrome - the MADDEC study

Objectives. Acute coronary syndrome (ACS) is associated with high mortality. Charlson comorbidity index (CCI) was designed over 30 years ago to measure the impact of pre-existing comorbidities on long-term survival of the patient. We wanted to re-evaluate the performance of CCI and its components in modern setting. Design. This is a retrospective study of 1576 consecutive patients undergoing invasive evaluation and treated for ACS in single tertiary center between 2015-2016. Mortality was analyzed in timeframes of 1, 6 and 24 months. CCI-scores were retrieved from written medical records and complimented with data from electronic sources. The performance of CCI and its components was compared to the GRACE-score measuring patients' status upon hospital admission. Results. Population mean age at baseline was 69.3 (SD 11.8) years and 69.1% of the patients were male (n = 1089). Most of the components of CCI associated significantly with mortality at all timeframes despite adjusting for age but only diabetes and congestive heart failure associated with mortality at all time points after adjusting for GRACE-score. CCI associated with mortality [GRACE adjusted HR-values of single unit increase of CCI after 1, 6 and 24-month follow-up: 1.12(95% CI:1.00-1.25), 1.17(1.07-1.29) and 1.24(1.16-1.33)]. CCI performed modestly with its AUC-values ranging between 0.755 and 0.784, with prognostic performance increasing with longer follow-up. Adding components of CCI did not significantly improve risk prediction over GRACE-score. Conclusions. In conclusion, CCI or its individual components measuring the impact of comorbidities on overall mortality does not provide any significant value compared to GRACE-score during up to 2 years of follow-up.