PURPOSE: Lung transplant for pulmonary hypertension (PH) has undergone significant change. After discovery of the ability of the overloaded right ventricle(RV) to remodel, heart-lung transplants were no longer indicated as they tolerate primary lung transplant. The impact of lung transplant on the left ventricle (LV) has not been studied. We sought to evaluate the incidence and morbidity of LV dysfunction post transplant in the ICU.
METHODS: We performed a retrospective review of all bilateral lung transplants for PH between 2003-2010.
RESULTS: Twenty patients were identified, 45 % of whom had new early LV systolic dysfunction post operatively. The LV dysfunction population had a prolonged duration of PH (5 years vs. 3.4 years) and worsened preoperative RV function (grade 3.8 vs 3.2). Their mean pulmonary arterial pressures were comparable (54mmHg vs 59mmHg). There were no significant differences in intraoperative and donor variables. LV dysfunction was associated with a higher incidence of immediate grade 3 primary graft dysfunction (PGD) (86% vs 67%), however a shortened duration of mechanical ventilation (20 vs 34 days), ICU LOS (20 vs 35 days) and hospital LOS (59 vs. 78 days).
CONCLUSIONS: This is the largest description of LV failure following lung transplant for PH. The theories for LV failure are multifactorial. Myocyte atrophy renders the LV relatively weak after years of being underworked with low preload from the RV. The LV preload suddenly increases post transplant which may cause it to fail after the RV is exposed to a new afterload. This is supported by the prolonged duration of PH prior to transplant seen in the LV dysfunction group. Myocardial depression could be attributed to the acute inflammatory state post transplant as this group had more severe, immediate PGD. PGD is associated with upregulation of TNFα and IL6 which have been implicated in myocardial dysfunction of sepsis.
CLINICAL IMPLICATIONS: Interestingly, LV dysfunction was associated a significantly shorter duration of mechanical ventilation, ICU LOS and hospital LOS. As seen in sepsis, this suggests that the change could be adaptive.
DISCLOSURE: The following authors have nothing to disclose: Laveena Munshi, Marc De Perrot, Laura Hawryluck
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