Serum LDH levels are associated with pulmonary hypertension and early mortality. (A) Compared to patients without pulmonary hypertension (TRV < 2.5 m/s, n = 138), higher mean LDH values are seen with mild pulmonary hypertension (TRV 2.5-2.9 m/s, n = 51) and moderate-severe pulmonary hypertension (TRV > 2.9 m/s, n = 21; P < .001, Kruskal-Wallis test). (B) Kaplan-Meier plot of survival of patients with lower or higher than median steady-state LDH levels (defined as < 315 IU/L or ≥ 315, respectively; P = .02, log-rank test).