Investigation of Coronary and Pulmonary Circulatory Parameters in Systemic Sclerosis

Systemic sclerosis (SSc)is a multiorgan autoimmune disease characterized by fibrosis of the skin and internal organs. Cardio-pulmonary manifestation in systemic sclerosis (SSc) patients has significant impact on the prognosis. Several elements of the heart and lung involvement encountered frequently in combination. Clinically apparent SSc cardiac involvement is recognized as poor prognostic factor, and in our experience it is the most frequent cause of death among SSc patients. Moreover arrhythmias, diastolic and less frequently systolic dysfunction considerably interfere with the quality of life of these patients. Cardiac involvement includes primary cardiac disorders like fibrosis of the contractile elements, ischemia due to the involved microcirculation and/or to the epicardial coronaries and some secondary ones like consequences of systemic or pulmonary hypertension.

Autopsy identifies fibrosis of the myocardium in up to 80 percent of cases. Its distribution is unrelated to epicardial coronary stenosis, and inflammatory processes are thought to play substantial role in its evolution. Microvascular disease (MVD) that causes reduction of the vasodilatory capacity independently from epicardial coronary disease (CAD), is known for several decades. Short term benefits from vasodilatory treatment has been also reported in some latest studies.

Symptoms of the elements of cardio-pulmonary involvement overlap and coronary abnormalities alike MVD were also found in asymptomatic patients. Recently prevalence of CAD is reported to be similar to gender, age and symptom matched controls. Atypical clinical presentations were predominant and nevertheless these findings indicate that SSc patients are not free from CAD.

Clarification the causes of reduced exercise capacity, chest pain and faint in SSc is a challenging task and requires multidisciplinary approach. Driven by its high mortality and due to the recent emergence of effective therapy SSc patients are regularly screened for pulmonary hypertension (PAH). Clinical presentation of scleroderma related PAH is unspecific. Fatigue, chest pain and dyspnea may be related to other organs, such as the lung, musculoskeletal system or the esophagus. The definitive diagnosis of PAH still depends on the results of right heart catheterization (RHC). As the non-invasive diagnostics are influenced and to some extent restricted by multiple clinical manifestations, RHC is performed liberally in symptomatic patients. Still a considerable proportion of patients who underwent RHC have normal pulmonary pressure and the cause of symptoms may remain obscure as cardiac involvement may not be correctly diagnosed or entirely overlooked.

We intend to characterize coronary artery disease in symptomatic SSc patients by means of a prospective cross-sectional study consisting of organized screening of SSc patients and systematic left heart catheterization (coronary angiography, and coronary flow reserve estimation) in all patients referred to RHC. Prognostic impact of the different manifestations are determined during five-year follow-up of the study.