Evolution of resting lung function in the first year after cardiac transplantation

The aim of our study was to characterize the time course and magnitude of the changes in lung function in the first year after cardiac transplantation. Resting pulmonary function tests (spirometry, lung volumes and transfer factor) were performed in 14 patients prior to and at 1, 3 and 12 months after surgery. Resting central haemodynamics were also measured serially in the first year post-transplantation. Before transplantation, patients had impaired resting lung function with marked decrease in transfer factor (TL,CO). Although resting central haemodynamics improved markedly within the first week after cardiac transplantation, lung function (forced expiratory volume in one second (FEV1)) was significantly improved only at three months post-transplantation. TL,CO, however, decreased further early after cardiac transplantation. By 12 months, FEV1 and forced vital capacity had increased significantly by 31 and 33%, respectively, while total lung capacity increased by 22%. On the other hand, TL,CO did not increase significantly and remained well below normal at 12 months after cardiac transplantation, at a value equal to 68% of predicted. We conclude that the resting abnormalities in lung function of most patients with heart failure are reversible after cardiac transplantation, except for TL,CO which remains below normal values. Recovery of lung function, however, lags behind the improvement in cardiac function.