Pre-operative Pulmonary Function and Association with Left Ventricular Assist Devices Outcomes

Abstract

Introduction Comorbidities including pulmonary disease are common in patients undergoing LVAD implantation. The impact of pre-implant pulmonary function on post-implant LVAD outcomes has not been comprehensively explored. In this study, we examined the association between pre-implant pulmonary function on post-implant outcomes. Methods A retrospective review of 415 primary LVAD implants at our center between 2008 and 2019 identified 251 patients with pre-implant pulmonary function tests (PFT), of which 248 had pre-implant chest CT scans. PFT results were classified as obstructive or restrictive and were sub-stratified by severity. Chest CT scan findings were assessed for presence of fibrosis or emphysema. Our primary outcome was 1-year mortality. Secondary outcomes included reintubation, days on mechanical ventilation, post-operative pneumonia, ICU length of stay (LOS), hospital LOS and 30-day mortality. Continuous variables were evaluated using two-sample Student's t-test or Wilcoxon test. Categorical variables were evaluated using χ2 test or Fisher's exact test. The group comparison in outcomes were assessed using logistics regression and linear regression. Results PFTs and chest CT scans were completed at a median of 42 days (IQR 18-127 days) and 26 days (IQR 10-63 days), respectively, prior to LVAD implantation. 84 patients (35%) had obstructive lung disease (52% moderately severe or severe) and 132 patients (55%) had restrictive lung disease (23% moderately severe or severe). Lung diffusing capacity for carbon monoxide (DLCO) was normal in 23% of patients and reduced in others by mild (29%), moderate (41%) or severe (7%) degrees. Presence or severity of either obstructive or restrictive lung disease on PFTs were not associated with primary or secondary outcomes. Severe reduction in DLCO and presence of fibrosis on chest CT scan were both strongly predictive of mortality at 30 days (OR 10.0, CI 1.52-65.63, p Conclusions Pulmonary disease is common in patients undergoing LVAD implantation. The presence and severity of obstructive or restrictive lung disease on pre-implant PFTs were not predictive of post LVAD outcomes. However, a severe reduction of DLCO and pulmonary fibrosis on pre-implant chest CT scan were associated with 30-day and 1-year mortality.