Associations between left ventricular myocardial involvement and endothelial dysfunction in systemic sclerosis: Noninvasive assessment in asymptomatic patients

Objectives: Systemic sclerosis (SSc) is a multisystem disorder characterized by widespread vascular lesions and fibrosis of skin and distinct internal organs. Cardiac involvement is a common finding in SSc, but often clinically occult. Aim of the study: To analyze possible associations of left ventricular (LV) myocardial function with coronary flow reserve (CFR) and endothelial function in asymptomatic patients with SSc. Methods: 30 healthy patients and 33 age- and sex-comparable asymptomatic patients classified as having either diffuse (18 patients) or limited form (15 patients) of SSc underwent standard Doppler Echo, Doppler myocardial imaging, Strain rate imaging of interventricular septum and LV lateral wall, transthoracic CFR of left anterior descending coronary vessel (after dipyridamole infusion), and brachial artery vasodilatation measurement (Vivid 7, GE Medical Systems Inc). Results: LV diameters and ejection fraction were comparable between the two groups, while systolic pulmonary pressure (P < 0.001) was increased in SSc. By chest-CT, 15 SSc patients showed interstitial pulmonary fibrosis. Serological antibodies analysis detected anti-centromere pattern in 14 SSc patients, and anti Scl-70 in 19 patients. In SSc, LV myocardial early diastolic peak velocity, peak systolic strain rate and strain were both reduced in basal and middle interventricular septum, and in basal and middle LV lateral wall. Both CFR (P < 0.0001) and endothelial flow-mediated dilatation (P < 0.001) were significantly lower in SSc patients. By stepwise forward multivariate analyses, CFR (P < 0.001) and endothelial function (P < 0.001) were powerful independent determinants of middle LV strain. Conclusions: Strain rate imaging, transthoracic CFR, and brachial artery flow-mediated dilatation are valuable noninvasive and easily repeatable tools for detecting LV myocardial and vascular involvement caused by SSc. Their combined use may be therefore useful for early identifying patients with more diffused and severe form of SSc, ideally in asymptomatic cases prior to the development of severe vasculopathy, when it may be most feasible to modify the disease process by new potential therapies.