Screening of Right Descending Pulmonary Artery in Chronic Obstructive Pulmonary Disease by Discriminant Functions

The presence of pulmonary arterial hypertension (PH) in patients with COPD has been shown to relate to the width of right descending pulmonary artery (rDPA). rDPA> 16 mm is the best discriminant between those patients with and wit-hout PH. The aim of this retrospective study was to investigate the enlargement of rDPA and the factors which affected this parameter in 118 patients with stable COPD. Patients were divided into two groups according to width of rDPA (Gro-up 1: rDPA< 16 mm, Group 2: rDPA ≥ 16 mm). Stepwise discriminant analysis was perfomed to evaluate the most impor-tant factors related with diameter of rDPA. PaO2 and hematocrit (Hct) were the most relevant factors for the discrimination of the two groups. There was statically significant positive correlation between rDPA and smoking (pack-yr) (p< 0.05), RBC (p< 0.05), Hct (p< 0.01), PaCO2 (p< 0.05). Also negative correlation was found between rDPA and PaO2 (p< 0.001), %SaO2 (p< 0.01). In conclusion, hypoxemia and polycytemia were the most significant factors related with enlargement of rDPA in pati-ents with COPD