Associations of right ventricular myocardial function with skin and pulmonary involvement in asymptomatic patients with systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a multisystem disorder characterized by widespread vascular lesions and fibrosis of the skin and specific internal organs. Cardiac involvement is a common finding in SSc, but often clinically occult. The aim of the present study was to analyze both left and right ventricular (RV) myocardial function in patients with SSc, and their relation to other instrumental features of the disease.
METHODS: Twenty-five healthy subjects and 23 age- and sex-comparable asymptomatic patients classified as having either diffuse (11 patients) or limited cutaneous (12 patients) SSc underwent clinical examination, serological analysis, high-resolution chest computed tomography, standard Doppler echocardiography and pulsed Doppler myocardial imaging (DMI) of both the mitral and tricuspid annuli. SSc was classified using the modified Rodnan skin score (mRSS) into high mRSS (score > or = 10) and low mRSS (score < 10).
RESULTS: Serological antibody analysis revealed the presence of antinuclear antibody in all patients, an anticentromere pattern in 8 patients, and anti-Scl-70 antibodies in 15 patients. Eleven patients were diagnosed with interstitial pulmonary fibrosis at chest computed tomography. Standard Doppler echocardiography revealed that the left ventricular mass index and ejection fraction were comparable between the two groups, while the RV end-diastolic diameter was increased in SSc (p < 0.01). The tricuspid inflow peak E and E/A ratio were slightly decreased in SSc (p < 0.01), while the systolic pulmonary pressure was increased (p < 0.0001). DMI analysis revealed, in SSc, an impaired RV myocardial early-diastolic (Em) peak velocity (p < 0.001) as well as a prolonged myocardial relaxation time (RTm) (p < 0.001) only at the tricuspid annulus level, even after correction for age, sex, heart rate and left ventricular mass index. Independent inverse associations of the RV Em peak velocity with both the Rodnan skin score (beta coefficient = -0.62, p < 0.0005) and the pulmonary systolic pressure (beta coefficient = 0.71, p < 0.0001), as well as the independent inverse correlation of the same RV Em peak velocity with interstitial pulmonary fibrosis (odds ratio 0.68, 95% confidence interval 0.45-0.83, p < 0.0005) in SSc patients were assessed at multivariate analysis. In addition, the RV Em velocity was an independent predictor of the anti-Scl-70 antibody pattern (odds ratio 0.68, 95% confidence interval 0.45-0.83, p < 0.01). Of note, a RV Em peak velocity < 0.11 m/s well selected SSc patients with pulmonary artery pressure > 35 mmHg, pulmonary fibrosis, a high mRSS, and an anti-Scl-70 antibody pattern.
CONCLUSIONS: The relationships of RV myocardial diastolic dysfunction with both skin and pulmonary involvement as well as with the serological antibody pattern emphasizes the ability of DMI to identify patients with a more diffuse and severe form of SSc. This issue may be critical for the early identification of those SSc patients who are at higher risk of cardiac impairment, ideally when they are still asymptomatic before developing severe vasculopathy.