Left ventricular dysfunction in a cohort of new onset idiopathic inflammatory myopathy without known heart disease

Abstract

Abstract Impaired myocardial function is linked to inflammatory mechanisms. Indeed, many systemic inflammatory diseases are associated to risk of developing heart disease. Idiopathic inflammatory myopathy (IIM; here Dermato- or polymyositis) are rare systemic inflammatory diseases, characterised by immune infiltration in muscle, presence of autoantibodies and cytokines in circulation leading to weakness and disability. IIM can involve extra-muscular tissues, e.g. heart, and is associ-ated with elevated risk for cardiovascular disease. Heart function in IIM is little investigated and has mostly been studied in patients at a chronic IIM stage or with a concomitant heart disease. To our knowledge, heart function has not been characterized at the early stage in IIM when the risk of inflammatory associated cardiomyopathy may be high. Our hypothesis is that patients at early-stage IIM may present with subclinical myocardial dysfunction that can be detected by echocardiography. We used echocardiography (echo) following clinical standards to investigate heart function in a cohort of 18 patients (61% females; age 46±12 years) with recent onset IIM (mean diagnosis time 5 month). Patients were recruited from the rheumatology clinic at Karolinska University Hospital, Stockholm, and had given written consent. None had previous heart disease. Echo parameters were compared to normal reference limits as established by the American Society for Echocardiography. Heart failure association (HFA)-PEFF score (≥2 p) was used to define left ventricular diastolic dysfunction (LVDD). Ejection fraction (EF) was generally preserved in the cohort with no patient displaying EF<55% (Table 1). Yet, 4 patients (22%) displayed reduced global strain (LVGLS; >−20%) suggesting presence of impaired myocardial contraction. In contrast, diastolic dysfunction was seen in several patients as indicated by one or more diastolic parameters outside normal rage (table 1). Moreover, when calculating HAVA-PEFF score 9 patients (50%) fulfilled criteria for LVDD. None of the patients displayed hypertension (>140/90 mmHg), or left ventricular hypertrophy. In a cohort of patients with recent onset IIM without known heart disease, we have found that diastolic dysfunction is prevalent with 50% of the patients fulfilling criteria for LVDD according to the HFA-PEFF score. This gives a high likelihood of fulfilling criteria for the diagnosis heart failure with preserved EF (HFpEF). We conclude that clinical echocardiography is important in the initial work up of IIM to screen for LVDD as the risk of heart failure is likely to be high. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Swedish Heart Lung Foundation