The relationship between global longitudinal strain and pulmonary function tests in patients with scleroderma and normal ejection fraction and pulmonary artery pressure: a case-control study

This study examined the relationship between global longitudinal strain (GLS) and pulmonary function tests (PFT) in patients with systemic sclerosis (SS) and normal ejection fraction (EF) and pulmonary artery pressure (PAP) and healthy controls. Sixty patients in two groups underwent extensive screening, including echocardiography, physical examination, the modified Rodnan Skin Score, and pulmonary function tests. Pulmonary interstitial disease was diagnosed by the pulmonary function test and by CT scan in case of indication. GLS score was computed as the mean peak systolic strain for 17 segments. The mean GLS score was - 18.36 +/- 2.1 in the case group and - 20.66 +/- 1.6 in the control group (P value < 0.001). GLS scores had a significant inverse relationship with the forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio (P value = 0.049) and both FEV and FVC in patients younger than 35 years old (P = 0.046 and 0.049, respectively). GLS scores had no significant relationship with time elapsed since the onset of skin manifestations, and Raynaud phenomenon, Rodnan score, EF, systolic PAP, or the six-minute walk test results. The patients' six-minute walk test had a significant positive relationship with FVC and right ventricular end diastolic diameter (P value = 0.018 and 0.047, respectively). According to our findings, GLS is significantly lower in patients with SS (with normal EF & PAP) than in healthy individuals. It is also related with certain pulmonary function indices including FEV1/FVC. The reduction in GLS is associated with reduced pulmonary function strength.