Table 3

Methods of cardiac assessment in IIM

MethodsAdvantagesDisadvantagesUsed in IIM
ECGCan detect ST segment and T wave abnormalities, arrhythmias and conduction abnormalities. May also give indications of left ventricular hypertrophy. Readily availableSome false positive and negative results. Clinical significance often unclear.Many studies, eg, 6–8
24 hour
ECG/Holter monitoring
Can detect arrhythmias, heart rate variability and ischaemiaRequires more resources than standard ECG18 21 70
Echo-cardiographyCan assess wall thickness, size of the four chambers, valve structure, systolic and diastolic function. Strain imaging and tissue doppler are newer methods used to assess cardiac function.Operator dependent. Low sensitivity for detection of myocardial inflammation and fibrosis14–18 21 57
Endomyocardial biopsyGold standard for detecting myocardial inflammation and fibrosis. Remains a choice for selected patients based on clinical indication.Unreliable if patchy lesions. Owing to high risk of complications, biopsies are usually considered unethical in studiesNo clinical data in IIM
Cardiac MR (CMR)Can image cardiac structure and function from any projection. Primary imaging modality when diffuse or localised myocardial fibrosis (late gadolinium enhancement or T1 mapping), or myocarditis (T weighted, T1 mapping or early gadolinium enhancement) is suspected.Time-consuming
Requires expensive technology
Limited availability
19 21 67 68
Cardiac 99mTc-PYP scintigraphyCan detect and quantify inflammation of the myocardium by increased 99mTc-PYP uptakeRequires supplementary CT to image structures. Time-consuming. Limited availability18 20 21
CTCan assess coronary artery calcification (CAC score). Good negative predictive value.Radiation22
Creatine Kinase (CK)Available and cheap
A CK-MB/CK total—ratio >3% usually indicates cardiac damage
In IIM, this ratio might be elevated even without cardiac involvement95, used in most IIM studies
 Troponin I
 Troponin T
Serum markers specific to myocardial damage, and are therefore preferred to detect cardiac involvement. Troponin I most specific to the myocardiumExpressed in fetal skeletal muscle and in healthy or regenerating adult skeletal muscle. Both troponin-T and troponin-I can be elevated in the presence of renal failure79 95–98
B-type natriuretic peptide
Marker of heart failureCan be elevated in the presence of renal failureNo data in IIM
  • IIM, idiopathic inflammatory myopathies.