In a cohort of 87 patients with PAH associated with connective tissue disease, levosimendan (0.1 μg/kg/min during 24 h) resulted in an improvement in mixed venous oxygen saturation, higher TAPSE and lower levels of NT-proBNP compared to enoximone given at 0.5 μg/kg/min [140]. The gene discussed is NPPB; the disease is connective tissue disorder.