The SOFA score is composed of scores from six organ systems (respiratory [R], cardiovascular [C], hepatic [H], coagulation [Co], renal [Re], and neurological [N]) graded from 0 to 4 according to the degree of dysfunction/failure. The aggregate score (total maximum SOFA score [TMS]) is calculated summing the worst scores for each of the organ systems (TMSOrg) during the ICU stay. We investigated the outcome discrimination of the TMS and the association with ICU length of stay (ICU-LOS) in patients (pts) with acute cardiovascular disorders.
812 consecutive pts (age 62 ± 13 years, 69.7% male, SAPS II 29 ± 14, 266 pts acute myocardial infarction, 161 pts unstable angina, 96 pts rhythm disturbances, 63 pts heart failure, 47 pts cardiac arrest, 179 pts other admission diagnosis) were included between 4/99 and 4/00. SOFA score was determined daily and TMS was calculated. Discrimination power of TMS for survivors (S) and non-survivors (NS) (hospital mortality [HM]) was assessed by the area under the Receiver Operating Characteristic (AUROC) curve. Survival curves were determined for TMS ≤ and >6 (criterion value) and compared with log-rank test. Association between TMS and survival was assessed with Cox regression analysis.
130 (16%) pts died. ICU-LOS was 3.8 (1–80) days. SOFA score was significantly higher for NS on day 1 to day 10. TMSOrg for N, Re and H correlated significantly with ICU-LOS. TMSORG for R, C, N and Re were significantly associated with HM (risk ratio [RR] + 95% confidence interval [CI]: R 1.8 [1.3–2.5], C1.5 [1.2–1.9], N 1.4 [1.2–1.7], Re 1.5 [1.2–2.0]). TMS correlated only moderately with ICU-LOS (r = 0.45, P < 0.001) but was strongly associated with HM (RR 1.5 [1.4–1.6]). The AUROC for TMS was 0.915 ± 0.015. Log-rank test demonstrated a significant difference (P < 0.001) between pts with TMS ≤ 6 and TMS > 6. RR for HM was 13.2 [8.6–20.1] in pts with a TMS > 6.
SOFA score is an excellent tool to describe the extent of organ dysfunction in critically ill cardiovascular pts. Moreover, the degree of organ dysfunction is associated with ICU-LOS and mortality. Survival rates were higher in pts with TMS ≤ 6, pts with a TMS > 6 were 13.2 times more likely to die.
Therefore SOFA score may be utilised for quality assessment or appraisal of new therapeutic strategies.