Introduction: Neurological complications are common complications after heart transplantation (HTx) and present with seizures, which are associated with significant morbidity. These neurologic complications occur predominantly in the early posttransplant period, especially in the first 3 months, owing to the accumulation of triggering factors, such as introduction of immunosuppressive drug. HTx for heart failure patients brings substantial hemodynamic changes early posttransplant. However, the relationship between hemodynamic changes and seizures remains to be investigated.
Materials and Methods: To investigate relationships between hemodynamic changes and seizures after HTx, we retrospectively reviewed consecutive 105 patients (mean age 39.2 ± 14.1 years, 82 males) who underwent HTx at our institution between May 1999 and October 2017. Data on patient characteristics and clinical outcomes were extracted from our transplant database and medical record review. Hemodynamic parameters were obtained before and 1 week after HTx. The diagnosis of seizure was based on direct observation by medical staff. Patient demographic characteristics, type of implanted left ventricular assist device, hemodynamic parameters, immunosuppressive regimen and clinical outcomes were compared between the seizure and non-seizure groups.
Results and Discussion: Over median follow-up of 1532 days [Interquartile range (IQR) 544-2703 days], 14 patients experienced seizures after HTx. In univariate analysis, there were significant differences between the two groups in history of cerebrovascular accidents before HTx (79% vs. 44% respectively: p = 0.02) and cardiac index after HTx (3.25 ± 0.62 vs. 2.69 ± 0.59: p = 0.02). The optimal cut-off of cardiac index was 2.8 L/min/m2 on ROC curve (AUC 0.74; Sensitivity 85.7%; Specificity 58.5%). Multivariate logistic regression analysis revealed that cardiac index is an independent risk factor of seizure after heart transplantation (Odds ratio: 1.18; 95% confidence interval: 1.02 to 1.39 per 0.1 L/min/m2; p = 0.02). There was no significant difference in survival between patients with seizures and without (at 5 years, 90% vs. 96.6% respectively: p = 0.40), but there was significant difference in hospital stay [106 (55-147) days vs. 54 (42-69) days: p = 0.02].
Conclusions: These data suggested that high cardiac index immediately after HTx be an independent risk factor of seizure after HTx. Controlling immediate postoperative cardiac output might be important to reduce seizure and hospital stay after HTx.