Long-term survival and cognitive function according to blood pressure management during cardiac surgery. A follow-up

Background: Cardiac surgery is associated with a risk of complications, including post-operative cognitive dysfunction (POCD). In the randomized Perfusion Pressure Cerebral Infarcts (PPCI) trial, we allocated cardiac surgery patients to either a low-target mean arterial pressure (40-50 mm Hg) or a high-target pressure (70-80 mm Hg). The study found no difference in the volume of new ischemic cerebral lesions nor POCD, but 30-day mortality tended to be higher in the high-target group. In the present study we did a long-term 3-year follow-up to assess survival and level of cognitive functioning. The primary hypothesis was that patients allocated to a high-target blood pressure had a higher long-term mortality at 3-year follow-up.

Methods: We determined long-term mortality of patients included in the PPCI trial at 3-year follow-up using national registries and we assessed POCD using a cognitive test battery. Subjective level of functioning was assessed with questionnaires. POCD and subjective functioning at follow-up were evaluated in logistic regression models.

Results: Among the 197 patients who participated in the original study, there was no significant difference in mortality over a median of 3.4 years according to blood pressure target during cardiopulmonary bypass (hazards ratio 1.23 [high vs low] 95% confidence interval: 0.50-3.02, P = .65). POCD was found in 18.9% and 14.0% in the high-target and low-target groups, respectively adjusted odds ratio 1.01 (CI 95% 0.33-3.12). No differences were found for subjective functioning between groups.

Conclusions: No difference in mortality nor in the level of cognitive functioning was found according to blood pressure target during cardiac surgery long-term at 3-year follow-up.