Background Cardiac complication is one of leading causes of death in patients with systemic sclerosis (SSc). The incidence and predictors of myocardial involvement in patients with early SSc have been inconclusive.
Objectives The aims of this study were to (1) examine the prevalence of myocardial involvement determined by electrocardiography (ECG) and echocardiography; (2) compare the differences of those cardiac complications between DcSSc and LcSSc; (3) compare the differences of incidence rate (IR) of myocardial disease determined by echocardiogram between the two subtypes; and (4) determine the factors associated with myocardial involvement of early SSc.
Methods We used an inception cohort of SSc patients seen at the Rheumatology clinic, Chiang Mai University, between January 2010 and June 2014. All patients were assessed for demographic data, clinical manifestations, laboratory testing and had ECG and echo performed at the study entry and every 12 months thereafter. All ECG and echo results were interpreted by two experienced cardiologists.
Results One hundred and sixteen patients (69 females) with a mean (SD) age of 53.5 years (8.5) and mean (SD) disease duration (non-Raynaud's phenomenon: NRP) 12.1 months (9.2) at cohort entry were enrolled during a mean (SD) observation period of 2.3 years (1.4). Of 116 patients, there were 92 (79.3%) patients with DcSSc, 67 (57.8%) with NYHA class II, 81 (69.8%) with ILD determined by HRCT, 93 (80.2%) with positive anti Scl-70, 9 (7.7%) with positive anti-centromere antibodies, and 35 (30.2%) with telangiectasia. Mean (SD) values were: modified Rodnan's skin score 19.9 (11.2); hemoglobin 12.3 (1.8) g/dl; creatinine 0.8 (0.3) mg/dl; CK 431.9 (709.4) U/L; pro-BNP 958.9 (3,656.7) mg/dl; uric acid 5.6 (1.5) mg/dl; ESR 41.8 (30.2) mg/dl; estimated systolic pulmonary arterial pressure 32.8 (9.3) mmHg; %LVEF 67.7 (7.9). DcSSc had shorter duration from NRP to the study entry than LcSSc (11.1±8.6 vs 16.1±10.5 months, p=0.023). At enrollment, there were no significant differences in the prevalence of myocardial involvement determined by ECG between DcSSc and LcSSc consisting of conduction defect (21.7% vs 8.3%), abnormal ST-T change (5.4% vs 4.2%), abnormal T wave (4.3% vs 8.3%), and pathological Q wave (4.3% vs 4.2%). There was no significant difference in the prevalence of myocardial involvement determined by echocardiogram (presence of any wall hypokinesia without evidence of coronary artery disease) between the two groups (14.1% vs 8.3%). Of 62 patients diagnosed myocardial disease, 19 (30.6%) was found within the first two years from NRP. There was significant difference of the IR of myocardial disease determined by echo since NRP between DcSSc and LcSSc (22.1 vs 11.6 per 100 person-years, p=0.027). Cox-regression analysis revealed that only baseline pro-BNP>200 mg/dl [HR 2.35 (95%CI 1.13, 4.89)] was a predictor of myocardial involvement, whereas presence of telangiectasia [HR 0.47 (95%CI 0.24, 0.91)] showed negatively associated.
Conclusions Early SSc patients with DcSSc subtype had higher incidence rate of myocardial involvement than LcSSc. Only high pro-BNP predicted future myocardial complication of early SSc patients.
Disclosure of Interest None declared