Introduction: Pulmonary transplants have become the last-resort treatment option for end-stage lung diseases when all other therapeutic options have been exhausted. Since its inauguration, this procedure has proven its benefit in terms of survival at an increasing pace. Thanks to modern day medicine, its therapeutic application in terminal lung diseases has proportionally increased and as a result has become more accessible to patients whose treatment options have become limited or nulled. The demand for lung transplants remains higher than the supply, and as a result intricate selection of candidates is mandated. The main indications for a transplant are COPD, IIP, and cystic fibrosis. These pathologies have defined and formalized clinical criteria that characterizes a patient as eligible for a transplant. However, there exists patients whose diseases benefit from a pulmonary transplant but unfortunately, they do not have clear indications that would categorize them as eligible yet.
Objectives: Identify and draw conclusions as to what clinical parameters may be relevant when considering a patient for a lung transplant. The clinical parameters can include but are not limited to: pulmonary function, 6 min walk test, oxygen dependency, NYHA score and mean pulmonary arterial pressure, measured at the time of listing. The primary hypothesis is that some of these parameters will differ vastly among the different groups of diseases. As a result, the prerequisite for a lung transplantation will be specific to each disease or at least to a group of diseases.
Method: A retrospective observational monocentric analysis of a population of 64 patients who have undergone lung transplants at the CHUV between the years of 2004 to 2018 and have primary conditions that do not include COPD, cystic fibrosis, and idiopathic interstitial pneumonia. Anthropometric, pre-operative and post-operative data were collected for statistical analysis. Patients were categorized by their primary pathology into 4 main disease categories: vascular lung diseases, suppurative lung diseases, sarcoidosis, and interstitial lung diseases. The different disease groups were compared in terms of the different clinical parameters collected as well as survival post-transplant. Clinical parameters and their effect on survival post-transplant were also analyzed.
Results: This study included a total of 64 patients (68% women) and a median age of 49 years old (range 14- 66). A small majority of the patients were oxygen dependent (58%) at the time of the transplantation. In addition, two thirds of participants (66%) presented with pulmonary hypertension defined as mPAP >25mmHg. Vascular lung diseases in particular had younger patients, a shorter waitlist period, and higher mPAP measurements. The value of mPAP was the only statistically significant clinical parameter with an effect on survival post-transplant. There was no significant difference in terms of survival among the 4 disease groups. In addition, there was no significant difference between the survival of the most commonly transplanted diseases (COPD, IIP, and CF) compared to the less commonly transplanted diseases. Conclusion: Mean pulmonary pressure remained the only clinical parameter with a statistically significant effect on survival. Other clinical parameters did not reach significant values. However, the lack of a significant difference between the most commonly and less commonly transplanted pulmonary diseases suggests that evidence-based indications should exist for these ‘orphan’ pathologies.