Diastolic Dysfunction Increases the Risk of Primary Graft Dysfunction after Lung Transplant

Area of Science:

• Cardiology
• Transplantation Medicine
• Pulmonary Medicine

Background:

• Primary graft dysfunction (PGD) is a major complication following lung transplantation, leading to significant morbidity and mortality.
• While ischemia-reperfusion injury is a known cause of PGD, subclinical increases in pulmonary venous pressure from left ventricular diastolic dysfunction may exacerbate capillary leak and contribute to PGD.

Purpose of the Study:

• To investigate the association between left ventricular diastolic function, specifically the ratio of early mitral inflow velocity (E) to early diastolic mitral annular velocity (é), and the risk of developing PGD after lung transplant.

Main Methods:

• A retrospective cohort study analyzed transthoracic echocardiograms from lung transplant recipients (2004-2014) to assess E/é ratio and other diastolic function measures.
• PGD was defined by hypoxemia (PaO2/FiO2 ≤ 200) and allograft infiltrates at 48 or 72 hours post-reperfusion.
• Multivariable logistic regression was used to evaluate the relationship between E/é and PGD, adjusting for relevant clinical factors.

Main Results:

• A higher E/é ratio was significantly associated with an increased risk of PGD (OR, 1.93; P=0.04).
• An E/é ratio greater than 8 demonstrated a substantially higher risk of PGD (OR, 5.29; P=0.01), even after adjusting for recipient age, BMI, pulmonary arterial pressure, and pretransplant diagnosis.

Conclusions:

• Left ventricular diastolic dysfunction, as indicated by the E/é ratio, may be a contributing factor to the development of primary graft dysfunction after lung transplantation.
• Further research, including prospective trials, is warranted to explore whether optimizing left ventricular diastolic function can mitigate the risk of PGD.