Red Cell Distribution Width and Platelet Count as Biomarkers of Pulmonary Arterial Hypertension in Patients with Connective Tissue Disorders

Table 1

Main features of the study population and differences related to the presence of PAH. We report the main features of the whole study population; moreover, we compared CTD alone and CTD complicated by PAH. Categorical variables are shown as frequencies (%); continuous variables are shown as medians (IQR). Mann–Whitney and Fisher’s exact tests were used as appropriate.

Variables	Entire CTD population ()	CTD without PAH ()	CTD with PAH ()
Age (years)	68 (57-76)	62 (52-72)	74 (69-79)	0.0001
Gender (F/M)	127 (90.1)/14 (9.9)	110 (90.9)/11 (9.1)	17 (85.0)/3 (15.0)	0.42
Hb (g/dl)	12.9 (11.8-14.0)	12.9 (11.7-13.8)	12.0 (11.6-13.8)	0.35
RDW (%)	14.0 (13.2-15.5)	13.8 (13.1-15.0)	14.9 (13.5-17.2)	0.02
PLTs (×10^9/l)	228 (190-295)	244 (197.5-304.2)	205 (177-240)	0.005
BNP (pg/ml)	78.7 (35.3-182.1)	52.1 (29.7-102.2)	204.9 (81.0-465.5)	<0.0001
Creatinine clearance (ml/min)	82.5 (60.0-97.5)	89.0 (71.5-102.0)	65 (49.0-78.0)	0.0005
DLCO (ml/min/mmHg)	72.5 (52.0-87.0)	76.0 (64.0-87.2)	45.0 (40.2-54.7)	<0.0001
FEV1 (%)	96.0 (78.0-113.0)	101.0 (84.7-115.0)	103.0 (87.5-115.0)	0.98
FEV1/FVC (%)	107.0 (101.0-114.0)	109.0 (102.5-115.5)	107.0 (102.0-111.0)	0.41
sPAP (mmHg)	33 (25-45)	27 (23-31)	46 (42-57)	<0.0001
LVEF (%)	61.5 (57-66)	63.0 (59.0-67.0)	61.5 (55.5-65.5)	0.15

: number; CTD: connective tissue diseases; PAH: pulmonary arterial hypertension; Hb: haemoglobin; RDW: red cell distribution width; PLTs: platelets; BNP: brain natriuretic peptide; DLCO: diffusion lung capacity for carbon monoxide; FEV1: forced expiratory volume in the 1st second; FVC: forced vital capacity; sPAP: systolic pulmonary artery pressure; LVEF: left ventricular ejection fraction.