Prognostic Value of Charlson Comorbidity Index at 30 Days and 1 Year After Acute Myocardial Infarction

The Charlson comorbidity index (CCI), an indicator of comorbidity, has been used as an adjusting variable in multivariate models. Because of its prognostic value per se for cardiovascular complications after acute myocardial infarction (AMI), we sought to determine the predictive value of the CCI for all-cause mortality and recurrent AMI 30 days and 1 year after the index event. We analyzed 1035 consecutive patients admitted with the diagnosis of AMI (ST elevation=508 and non-ST elevation=527). The composite end-point was determined after 30 days (13.9%) and 1 year (26.3%) of follow-up. The CCI was calculated on admission, and other variables with prognostic value were also recorded. CCI was stratified in 4 categories: 1: CCI=0 (control), 2: CCI=1, 3: CCI=2,4: CCI>3. Cox proportional risks analysis was used for the multivariate analysis, and the C-statistic was calculated to assess the discriminative power of the models. Hazard ratios (95% CI) estimated for each category of CCI were: 2=1.69 (1.10-2.59), 3=1.78 (1.08-2.92) and 4=1.57 (0.87-2.83) at 30 days; 2=1.62 (1.18-2.23), 3=2.00 (1.39-2.89) and 4=2.24 (1.50-3.36) at 1 year. Comparisons with the C-statistic between the nested multivariate models (with and without CCI) yielded values of 0.765 vs 0.750 after 30 days, and 0.751 vs 0.735 after 1 year. Our data indicate that CCI is an independent predictor of mortality or recurrent AMI 30 days and 1 year after the index AMI. El índice de Charlson (iCh) ha sido utilizado como variable de ajuste en modelos multivariables como indicador de comorbilidad. Debido a que su valor pronóstico per se para complicaciones cardiovasculares tras un infarto agudo de miocardio no ha sido ampliamente evaluado, nos propusimos determinar su valor predictivo para muerte de cualquier causa y/o reinfarto, a 30 días y 1 año del evento índice. Se incluyó a 1.035 pacientes con el diagnóstico de infarto (508 con elevación del segmento ST y 527 sin elevación del segmento ST). La presencia de eventos se determinó a 30 días (13,9%) y a un año (26,3%). El iCh se calculó junto con otras variables de valor pronóstico en el momento del ingreso, y se establecieron 4 grupos: 1, iCh = 0 (control); 2, iCh = 1; 3, iCh = 2, y 4, iCh > 3. Para el análisis multivariable se utilizó la regresión de riesgos proporcionales de Cox; su poder discriminativo se evaluó mediante el índice C. Los riesgos relativos (RR) y el intervalo de confianza [IC] del 95% para las categorías del iCh fueron: a los 30 días,