Increased Incidence of LV Diastolic Dysfunction in PM/DM

TOPIC SERIES: CVD PREVENTION IN RHEUMATIC DISEASE

A cross-sectional population-based study in Denmark found that subclinical left ventricular diastolic dysfunction (LVDD), detected by noninvasive methods, is more frequent in patients with polymyositis (PM) and dermatomyositis (DM) as compared with healthy controls.  LVDD in these patients correlated with age, disease duration, myositis-specific autoantibodies (MSA), and myositis-associated autoantibodies (MAA). 

Furthermore, ^99mTc-pyrophosphate (^99mTc-PYP) scintigraphy pointed to myocardial inflammation as the underlying pathology in LVDD.  These findings were recently published in Arthritis Care & Research.

Patients with idiopathic inflammatory myopathies have an increased risk of developing cardiovascular disease (CVD), including coronary artery disease and myocardial disease. 

To better characterize the cardiac abnormalities present in patients with PM/DM, and to identify the relationships between disease-specific characteristics, echocardiographic findings, and cardiac function, researchers in Denmark utilized echocardiography with tissue Doppler imaging (TDI)  and ^99mTc-PYP scintigraphy techniques.

Patient data was retrieved from the Danish National Patient Register. Researchers included those patients ≥18 years old who fulfilled the Bohan and Peter criteria for definite or probable PM or DM between the years of 2000 and 2010. Patients with overlapping inflammatory syndromes, sporadic inclusion body myositis, and cancer-related myositis were excluded. Out of the 87 patients who fulfilled the inclusion criteria,  76 consented to participate in this study.

Healthy controls (HCs) were recruited who had no history of CVD or rheumatic diseases, and not taking any medication. They were matched with patients according to age and sex on group level. The Myositis Damage Index (MDI) was used to quantify the extent of cardiac pathology in patients with disease for more than 2 years.

All PM/DM study participants were evaluated for disease activity with the Health Assessment Questionnaire, the Myositis Intent-To-Treat Activity Index (MITAX), the physician global assessment of disease activity (MD global activity,and serum levels of C-reactive protein (CRP) and creatine kinase. MSA antibodies (anti–Jo-1, anti–PL-7, anti–PL-12, anti-OJ, anti-EJ, anti–signal recognition particle, and anti–Mi-2) and MAA antibodies (anti–PM/Scl-75, anti-PM/Scl-100, anti-Ro/SSA, and anti-Ku) were subsequently measured.

To evaluate baseline CVD measures, traditional CV risk factors and coronary artery calcification (CAC) were assessed. Standard 12-lead electrocardiogram (EKG) and 48-hour Holter monitoring were performed. Two cardiologists performed quantitative transthoracic echocardiograms. Patients then underwent ^99mTc-PYP scintigraphy imaging.

Researchers found that LVDD was more frequently found in patients with PM/DM as compare with HCs (12% vs 0%; P =.02). Patients with PM/DM also were more likely to have prolonged QRS and QT intervals (P < .007 and P < .001, respectively). A higher rate of supraventricular tachycardia was also found in patients with inflammatory myopathies.  

No significant differences in LV ejection fraction or systolic function were found between groups. Age (P =.001), disease duration (P =.004), presence of autoantibodies (P =.05), and high cardiac ^99mTc-PYP uptake (P =.006) were each significantly associated with LVDD after logistic regression analysis. 

Summary and Clinical Applicability

An increased prevalence of cardiac abnormalities, most notably LVDD, was found in patients with PM/DM compared with HCs.  LVDD appears to be associated with age, diagnosis, disease duration, and MSA/MAA autoantibody positivity.  Scinitgraphy results suggest that myocardial inflammation underlies the increased LVDD found in patients with PM/DM.

“LVDD was common in our patient cohort and was independently associated with diagnosis and duration of PM/DM, suggesting that echocardiography with TDI on a regular basis may be indicated in patients with PM/DM to detect heart involvement that might require treatment,” the authors concluded.

Limitations and Disclosures

• Small sample size and older age of patient group 
• No histologic confirmation of myocarditis was done by endomyocardial biopsy

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Reference

Diederichsen LP, Simonsen JA, Diederichsen AC, et al. Cardiac abnormalities in adult patients with polymyositis or dermatomyositis as assessed by noninvasive modalities. Arthritis Care Res (Hoboken). 2016;68(7):1012-20.