Abstract
BACKGROUND: In patients with systemic sclerosis (SSc), early detection of pulmonary hypertension (PH) improves survival. This study aimed to investigate whether a combination index (cPAT) of the tricuspid regurgitation jet peak gradient and the ratio of pulmonary artery (PA) diameter to aortic diameter measured by computed tomography (CT; PA ratio) can estimate the mean PA pressure (mPAP) and detect PH more accurately than conventional parameters in SSc patients. METHODS: A total of 36 SSc patients who underwent PH screening were retrospectively analyzed. All patients were screened for PH between 2013 and 2017 by echocardiography, CT, and right heart catheterization. Patients with mPAP > 20 mm Hg by right heart catheterization were diagnosed as having PH. Additionally, patients with an mPAP > 20 mm Hg, pulmonary vascular resistance > 2 Wood units, and PA wedge pressure ≤ 15 mm Hg, for whom other causes were ruled out, including group 2-5, were defined as having pulmonary atrial hypertension. RESULTS: Of 36 patients, 29 patients were female (81%), and the average duration of SSc was 7.5 years. The mPAP was significantly correlated with the tricuspid regurgitation jet peak gradient (r = 0.734), the PA ratio (r = 0.584), and the cPAT (r = 0.848). In receiver operating characteristic analysis to identify PH, the cPAT showed the highest area under the curve, 0.906, among the 3 parameters. Additionally, in receiver operating characteristic analysis to identify pulmonary atrial hypertension, the cPAT also showed the highest area under the curve, 0.851, among the 3 parameters. CONCLUSIONS: The cPAT is a new index combining echocardiogram and CT results that provides the most accurate noninvasive assessment of mPAP in SSc patients. The cPAT can also help detect PH early in SSc patients, thereby allowing for earlier treatment.