507 LONG-TERM SUBCLINICAL HEART INVOLVEMENT IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES


 
 
 Global longitudinal strain (GLS) is a validated and reproducible technique for the measurement of LV longitudinal deformation. There is strong evidence of the prognostic value of GLS in patients with HF and is associated with cardiac mortality independent of clinical and cardiac status. In the present study, we aimed to assess whether GLS can reliably predict prognosis in patients diagnosed with idiopathic inflammatory myopathies.
 
 
 
 We conducted a prospective observational study enrolling all consecutive patients referred to our clinic between June 2016 and January 2022 with a confirmed diagnosis of IIM and no overt cardiac disease. For each patient, echocardiogram and GLS calculations were done at baseline and at each follow-up. All patients enrolled have been revalued from two to four times during the median 2.5-year follow-up period.
 
 
 
 Forty patients (67% female, mean age 56±12 years) were consecutively enrolled. We detected a significant deterioration of the GLS of the LV (from -19.3±3.6%to -16.8±4.6%; p = 0.006) during the follow-up, while the GLS of the RV was unchanged. We also noticed an increase in the filling pressures as estimated through E/E’, which resulted to be statistically significant (6.5±3.9 to 9.0 ±3.5; p = 0.002), underlying a subclinical diastolic dysfunction of the LV. Traditional markers of systolic dysfunction, such as EF and TAPSE, did not show a significant worsening during the follow-up period. Patients developing a reduction in LV GLS >5% during follow-up experienced an increased incidence of cardiovascular-related death (19% vs 6%; p=0.03).
 
 
 
 Cardiovascular manifestations constitute a major cause of death in myositis. Although these complications rarely occur clinically, subclinical manifestations such as conduction disturbances, ventricular dysfunction, myocardial infarction and arrhythmias are often observed. This risk appears to increase especially in the first years after diagnosis. There is therefore a problem of the early recognition of patients who may develop heart disease. Several studies propose to use magnetic resonance imaging as a gold standard to select patients at risk, but its high cost and limited availability make it difficult to use as a screening test. The GLS, consistently with the estimated filling pressures, has demonstrated a high predictive power of cardiovascular-related death in our study, without a modification of the traditional systolic function values.
 
 
 
 The GLS has a high power predictive, it is low cost and highly repeatable, therefore in our opinion, it could play an important role as a screening test in identifying patients with a diagnosis of IIM at higher risk of developing cardiovascular-related death.
