Analogical reasoning and postoperative outcome. Predictions for patients scheduled for open heart surgery

We investigated whether postoperative outcome of open heart surgery is related to preoperative cognitive dysfunction. Patients ill enough to require open heart surgery frequently have gravely compromised circulation and, hence, possible brain damage. The Conceptual Level Analogy Test (CLAT), a new, rigorously constructed analogy test, was used to measure cognitive dysfunction. The results indicated that the CLAT, aministered preoperatively to open heart surgery patients, differentiated between patients having different types of postoperative outcome. A significant relationship between type of surgical procedure and poor postoperative outcome was also found; cardiac valvular surgery patients had significantly worse outcome than coronary bypass surgery patients. The incidence of good outcome (survival with no psychiatric complications) was 28% for cardiac valvular surgery patients with extremely poor preoperative CLAT scores, but 74% for valvular surgery patients with higher preoperative CLAT scores.