Biomedical and psychological risk in cardiac surgery: is EuroSCORE a more comprehensive risk measure than Stroke Index?

Objective: Several composite risk score indices, the most common being the Stroke Index and the European System for Cardiac Operative Risk Evaluation (EuroSCORE), have been developed to predict perioperative events such as cerebrovascular accidents or death. The main aim of the present study was to compare the preoperative associations between the Stroke Index or the EuroSCORE with anxiety, depression, memory, attention, and executive functions scores in patients undergoing cardiac surgery.

Methods: Ninety-one patients were required to perform a preoperative psychological evaluation. Trail Making Test A and B (TMT A/B), Memory with 10 and 30s interference, Digit Span Test, Phonemic Fluency, State and Trait Anxiety Inventory (STAI Y1/Y2), and Center for Epidemiological Study of Depression Scale (CES-D) were administered. The Stroke Index and the EuroSCORE were also considered for each patient. Correlations between the Stroke Index or the EuroSCORE, mood, and neuropsychological scores were performed.

Results: Seventy-seven patients completed the psychological evaluation. The Stroke Index was significantly correlated with TMT A (ρ=0.40, p=0.001), TMT B (ρ=0.38, p=0.001), Memory with 10s (ρ=-0.34, p=0.003) and 30s (ρ=-0.40, p=0.001) interference, and Phonemic Fluency (ρ=-0.29, p=0.01), but not with Digit Span Test (ρ=-0.18, p=0.13), STAI Y1 (ρ=0.08, p=0.44), STAI Y2 (ρ=0.06, p=0.56), and CES-D (ρ=0.11, p=0.31) scores. The EuroSCORE was significantly correlated not only with TMT A (ρ=0.49, p=0.001), TMT B (ρ=0.42, p=0.001), Memory with 10s (ρ=-0.23, p=0.04) and 30s (ρ=-0.35, p=0.002) interference, Phonemic Fluency (ρ=-0.28, p=0.01), and Digit Span Test (ρ=-0.28, p=0.01) but also with STAI Y1 (ρ=0.27, p=0.02), STAI Y2 (ρ=0.23, p=0.04), and CES-D (ρ=0.26, p=0.02).

Conclusions: While both the Stroke Index and the EuroSCORE account for the relationship between biomedical and cognitive risk factors in predicting perioperative risk, only the EuroSCORE also accounts for affective dysfunctions, which, in turn, have been proved to represent risk factors for perioperative adverse events. Therefore, compared with the Stroke Index, the EuroSCORE can be considered a more complete risk index in predicting perioperative risk. Data also suggest that a comprehensive preoperative evaluation of biomedical, mood, and cognitive performances might provide a more accurate mirror of the actual risk in patients undergoing cardiac surgery.