Table 1.

Overview of the main findings of the cluster analysis based on similarity of the patients’ clinical profiles. The frequency distribution of the various characteristics of the clusters are shown. Pulmonary involvement was defined as the presence of bibasilar fibrosis on standard chest radiographs or high-resolution computed tomography scans and/or pulmonary arterial hypertension detected by means of color Doppler echocardiography and confirmed by right-heart catheterization; esophageal involvement as barium radiography hypomotility; cardiac involvement as the presence of pericarditis, arrhythmia, or left ventricular congestive heart failure; renal involvement as malignant hypertension and/or rapidly progressive renal failure; hand involvement was defined as the presence of arthralgia, arthritis, flexion contractures, and/or digital ulcers. Data are percentages.