The impact of postoperative cognitive impairment on mid-term survival after heart transplantation

Abstract

Background: Heart transplantation is the definitive therapy for patients with end-stage heart failure. Antecedent studies reported that a substantial proportion of heart transplant recipients developed postoperative cognitive impairment in the long term. However, no studies have explored the association between postoperative cognitive impairment and survival after heart transplantation.

Methods: The data of 43 adult patients who underwent heart transplantation were consecutively enrolled and assessed using the MMSE and MoCA neuropsychological tests. Kaplan-Meier curves and Cox proportional hazards models were used for survival analyses. Primary component analysis was performed to integrate MoCA subtests into the "Attention factor," "Naming factor," and "Orientation factor."

Results: About 30% of the patients were diagnosed with short-term postoperative cognitive impairment. The impairment group was older and had lower baseline cognitive performances, larger LV diameter, worse MMSE decline and higher ratio of significant MoCA decline. Postoperative cognitive impairment was significantly associated with worse survival (P = .028). Multivariate Cox analyses showed that higher postoperative MoCA score was significantly associated with lower mid-term post-transplant mortality (HR = .744 [.584, .949], P = .017), in which "Attention factor" contributed to this association most (HR = .345 [.123, .970], P = .044) rather than "Naming factor" or "Orientation factor." Notably, preoperative cognitive impairment was closely related with postoperative cognitive impairment and also indicated the worse post-transplant survival (P = .015).

Conclusion: Postoperative as well as preoperative cognitive impairments were associated with a worse mid-term survival after heart transplantation, indicating that neuropsychological assessments before and after heart transplantation should be routinely performed for heart transplant recipients for better risk stratification.

Keywords: heart transplantation; neuropsychological test; postoperative cognitive impairment; survival.