Predictors of mortality in patients with Eisenmenger syndrome and admission to the lung transplantation waiting list

Background. Patients with Eisenmenger Syndrome (ES) have very severe irreversible pulmonary hypertension but the criteria for admitting such patients to a lung transplantation waiting list (LTWL) is not clear. Indeed it has been demonstrated that the natural survival of patients with ES is better than the survival achieved through lung transplantation: it follows that no guidelines are available for these patients’ admission to an LTWL. The aim of our study was to identify possible predictors of mortality in ES patients in order to reserve admission to the LTWL solely for those patients who would otherwise have the lowest probability of survival. Methods. Since 1991, 57 patients with ES from our rehabilitative centre were admitted to the LTWL of the Division of Cardiac Surgery at San Matteo Hospital, University of Pavia. At the time of the retrospective analysis, patients were divided into a group of non-transplanted survivors (27 patients - 47% of the total) and a group who had died prior to transplantation (16 patients - 28% of the total). The 14 transplanted patients (25% of the total) were not considered in the statistical analysis, considering transplantation as an “external eventâ€. Unpaired t tests were used to compare the following factors in the survivors and in those who died: sex, “complexity†of the congenital heart disease underlying the ES, previous cardiac surgery, arterial blood gases, pulmonary function and hemodynamic parameters. Moreover, a stepwise discriminant analysis was performed in order to define a possible set of prognostic factors. Results. PaCO2 was higher in those who subsequently died (36.15±7.42 mmHg) compared with those who survived (32.5±5.33 mmHg), although this difference did not reach a statistical significance (p=0.08). Discriminant analysis defined a model in which a) complexity of the congenital heart disease, b) sex (male) and c) cardiac output were predictive of a higher risk of mortality. Conclusions. This new knowledge can be used in the decision of admission to LTWL in ES patients.