Pos0842 Primary Heart Involvement in Systemic Sclerosis: The Role of Ventricular Ectopic Beats as Red Flags for Active Myocardial Inflammation Detected at Cardiac Magnetic Resonance

Background: Primary heart involvement(pHI) is frequent in systemic sclerosis(SSc), and is associated with a poor prognosis. Myocardial inflammation has been recently identified as an important and potentially reversible pathogenic event in SSc-pHI. However, no consensus has been reached on which SSc patients should perform cardiac magnetic resonance(CMR), and the clinical features associated with the presence of myocardial inflammation at CMR still remain poorly defined. Objectives: to investigate clinical, serological, and instrumental features of SSc patients associated with the presence of active myocardial inflammation at CMR. Methods: we retrospectively analyzed data from SSc patients who underwent CMR for a clinically suspected pHI, defined by the presence of cardiac symptoms (dyspnea, chest pain, palpitations, lower limbs edema, syncope) and/or signs (increase cardiac biomarkers, and/or presence of at least one abnormality at echocardiography and/or 24h-ECG-Holter) in the absence of progressive interstitial lung disease, WHO III-IV or worsened pulmonary arterial hypertension, renal failure, diagnosed coronary artery disease or other cardiac conditions. All patients underwent a comprehensive evaluation of disease characteristics and organ involvement, chiefly cardiac involvement, including: signs and symptoms of heart disease, serum levels of high-sensitive troponin-T(hsTnT) and NT-proBNP, inflammatory markers, ECG and 24h-ECG Holter, echocardiography and CMR. At CMR we analyzed: biventricular function, left and right chambers size, myocardial edema on STIR images, T2 myocardial/skeletal muscle ratio, early and late gadolinium enhancement (EGE and LGE), native T1 mapping, T2 mapping, and extracellular volume(EVC). Univariate and multivariate analysis were performed. A p value <0.05 was considered as statistically significant. Results: 100 SSc patients (females 85%; mean age 53.0±13.2 years; anti-topoisomerase-I positivity 41%; diffuse cutaneous subset 34%; early disease <3 years 50%; on immunosuppressive therapy: 58%) with suspected pHI were enrolled. Clinical and demographic characteristics are reported in Table 1. Overall, at least one CMR abnormality suggestive for pHI was detected in 78 cases(78%), with increased ECV as the more frequent finding (46/83 patients with available EVC[56.7%]), followed by increased T1 mapping (42/88 patients with available T1 mapping[47.7%]) and LGE areas(44%), while increased T2 mapping and edema on STIR images were present in 47.7% (42/88 patients with available T2 mapping) and 24% of cases, respectively. Considering the 78 patients with positive CMR, 50 of them(64.1%) had CMR signs of active inflammation (STIR edema and/or T2 mapping ≥53 ms and/or increased T2 ratio), while 28(35.9%) had signs of chronic cardiac involvement (increased ECV ≥28% and/or T1 mapping ≥1045 ms and/or LGE areas, without edema). At univariate analysis, patients with active myocardial inflammation at CMR more frequently had anti-RNA-polymerase-III antibodies(p=0.030), arthritis(p=0.016), ventricular ectopic beats(VEBs) at 24h-ECG Holter(p=0.012), and diffuse cutaneous subset(p=0.057, even though not statistically significant), with respect to patients with chronic CMR myocardial involvement at CMR or with negative CMR(Table 2). At multivariate analysis, the presence of VEBs emerged as a predictive factor for active myocardial inflammation at CMR(p=0.031, CI 1.142-15.167). Considering patients with early SSc, CMR features of active myocardial inflammation were associated with diffuse cutaneous subset(p=0.039) and VEBs at 24h-ECG-Holter(p=0.043) at univariate analysis. Conclusion: the presence of VEBs at 24h-ECG Holter may serve as a predictive factor for an active myocardial inflammation detected at CMR in SSc patients with suspected pHI. The early detection of myocardial inflammation is crucial to promptly identify SSc patients eligible for immunosuppressive therapy. Our data suggest that 24h-ECG Holter should be routinely performed to triage SSc patients to decide when CMR with mapping techniques should be mandatory in those with VEBs. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.