Impaired pulmonary function and right ventricular morphology in well‐healed burn survivors is related to aerobic capacity and not severity of burn injury

Abstract

Acute pulmonary dysfunction—second to inhalation injury—is prevalent in burn survivors, and is associated with a 24‐fold increase in morbidity and mortality. Systemic inflammation is known to persist many years post‐injury and likely compromises the pulmonary vasculature and respiratory gas exchange in well‐healed burn survivors. Whether pulmonary dysfunction in this population is related to right ventricular (RV) morphology and function remains unknown. Twenty‐six well‐healed burn survivors (age: 42 ± 14; body mass index: 28.1 ± 5.8; body surface area [BSA] burn: 49 ± 22 [range: 20–88]) and 11 age, sex and activity matched controls (age: 34 ± 9; body mass index: 28.2 ± 5.3) were recruited for assessment of maximal aerobic capacity (VO2max; via a graded cycle ergometer test), pulmonary function (diffusing capacity of the lungs for carbon monoxide [DLCO]) and RV morphology and function (via magnetic resonance imaging). Burn survivors were grouped post‐hoc by DLCO and classified as having either low (≤80% predicted; n = 6; %BSA burn: 42 ± 11), moderate (80–100% predicted; n = 11; %BSA burn: 42 ± 23), or high (>100% predicted; n = 9; %BSA burn: 61 ± 22) diffusing capacity. Group differences in RV morphology and function were assessed by one‐way ANOVA with Bonferroni correction where appropriate, and relationships between variables were assessed by partial correlation after controlling for body mass. Group differences were observed between those with low and high diffusing capacity in RV morphology (RV end‐diastolic volume [EDV] index: 73 ± 10mL/m2 vs. 81 ± 11mL/m2 vs. 95 ± 15mL/m2 vs. 84 ± 13mL/m2, low vs. moderate vs. high vs. control, respectively; ANOVA P = 0.012), but not RV function (RV ejection fraction: 54 ± 7% vs. 51 ± 9% vs. 53 ± 6% vs. 51 ± 10%, low vs. moderate vs. high vs. control, respectively; ANOVA P = 0.94). However, correlational analyses revealed that these group differences were primarily related to maximal aerobic capacity, after controlling for body mass (RV EDV vs. VO2max, r = 0.48, P = 0.003; DLCO vs. VO2max, r = 0.77, P < 0.001; RV EDV vs. DLCO, r = 0.57, P < 0.001). Taken together, we interpret these data to reflect RV remodeling due to lower maximal aerobic capacity, as opposed to frank impairments related to burn‐induced pulmonary dysfunction, and thus support a role for aerobic exercise training to improve cardiac function in well‐healed burn survivors.Support or Funding InformationProject funded by NIH GM068865This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.