Prevalence and Impact of Restrictive Lung Disease in Liver Transplant Candidates

Abstract

We investigated the prevalence of spirometric restriction in liver transplantation (LT) candidates and the clinical impacts of restriction. We performed a cross-sectional study within the Pulmonary Vascular Complications of Liver Disease 2 (PVCLD2) study, a multicenter prospective cohort study of patients being evaluated for LT. Patients with obstructive lung disease or missing spirometry or chest imaging were excluded. Patients with and without restriction, defined as a forced vital capacity (FVC) <70% predicted, were compared. Restriction prevalence was 18.4% (63/343). Higher Model for End-Stage Liver Disease-sodium score (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02-1.11; P = 0.007), the presence of pleural effusions (OR, 3.59; 95% CI, 1.96-6.58; P < 0.001), and a history of ascites (OR, 2.59; 95% CI, 1.26-5.33; P = 0.01) were associated with the presence of restriction, though one-third with restriction had neither pleural effusions nor ascites. In multivariate analysis, restriction was significantly and independently associated with lower 6-minute walk distances (least squares mean, 342.0 [95% CI, 316.6-367.4] m versus 395.7 [95% CI, 381.2-410.2] m; P < 0.001), dyspnea (OR, 2.69; 95% CI, 1.46-4.95; P = 0.002), and lower physical component summary Short Form 36 scores indicating worse quality of life (least squares mean, 34.1 [95% CI, 31.5-36.7] versus 38.2 [95% CI, 36.6-39.7]; P = 0.004). Lower FVC percent predicted was associated with an increased risk of death (hazard ratio, 1.16; 95% CI, 1.04-1.27 per 10-point decrease in FVC percent predicted; P = 0.01). Restriction and abnormal lung function are common in LT candidates; can be present in the absence of an obvious cause, such as pleural effusions or ascites; and is associated with worse exercise capacity, quality of life, and survival.

FIG. 1.

The selection of study sample.

FIG. 2.

Restriction and exercise capacity. (A) Least squares mean for 6MWD in patients with and without restriction after adjustment for age, sex, race, BMI, MELD-Na scores, and pleural effusions. Markers show the point estimates, and whiskers show the 95% CI. (B) Generalized additive model plots depicting the relationship between FVC percent predicted and 6MWD after adjusting for age, sex, race, BMI, MELD-Na scores, and pleural effusions.

FIG. 3.

Restriction and physical quality of life. (A) Least squares mean for PCS scores in the control group and in patients with restriction after adjustment for age, sex, race, BMI, MELD-Na scores, and pleural effusions. The markers show the point estimates, and whiskers show the 95% CI. (B) Generalized additive model plots depicting the relationship between FVC percent predicted and PCS scores after adjusting for age, sex, race, BMI, MELD-Na scores, and pleural effusions.

FIG. 4.

FVC percent predicted and cumulative incidence of death and transplantation. LT candidates with an FVC percent predicted below the median (84.4%) had (A) a higher cumulative incidence of death (P = 0.01) and (B) a similar cumulative incidence of transplantation (P = 0.72).