Table 5.
Investigational findings in patients with IIM (key studies)
| Author (year of publication) | Study group (n) | Diagnosis | Study design | Key observation | Country |
|---|---|---|---|---|---|
| Electrocardiogram (ECG) | |||||
| Deveza et al. [29] (2014) | 112 |
DM (n = 78) PM (n = 34) |
Cross-sectional study | One-third of patients had ECG abnormalities namely conduction disorders, chamber enlargement and rhythm disturbances. The rhythm disturbances included ventricular extrasystole, atrial fibrillation, first-degree AV block, supraventricular tachycardia, supraventricular extrasystoles. All these abnormalities were more frequent in PM than in DM (50% vs. 24.4%, p = 0.008). The study, however, did not find any significant difference in ECG abnormalities between patients and controls, except for a higher prevalence of left ventricular hypertrophy in the former | Brazil |
| Triplett et al. [81] (2020) | 109 | IMNM | Retrospective study | In patients with IMNM, an abnormal ECG was documented in 55 out of 86 patients. Of the various abnormalities, prolongation of corrected QT interval (QTc) was the most frequent | USA |
| Cox et al. [82] (2010) | 51 | Sporadic IBM | Cross-sectional study | Patients with IBM did not have increased risk of cardiac involvement compared to general population as evidenced by the similar frequencies of ECG abnormalities between the two groups | Netherlands |
| Wang et al. [83] (2014) | 51 | DM | Patients with DM had no clinically evident cardiovascular disease assessed using Doppler ECG. Authors reported a statistically significant association between LVDD and duration of the disease, pointing towards subclinical cardiac involvement with disease advancement | China | |
| Nuclear Cardiac Imaging | |||||
| Diederichsen et al. [84] (2016) | 76 |
DM (n = 24) PM (n = 52) |
Cross-sectional study | Age, disease duration, presence of myositis specific or associated autoantibodies and high cardiac 99m Tc-PYP uptake were found to be associated with LVDD. This association of LVDD with increased cardiac 99m Tc-PYP uptake indicated myocardial inflammation as a primary cause of cardiac involvement in IIM patients | Denmark |
| Echocardiography | |||||
| Plazak et al. [85] (2011) | 15 | DM/PM | Cross-sectional study | This study of patients with autoimmune disease included 15 DM/PM patients. Pathologic valvular leaflet thickening and/or pericardial thickening was found in 46.7% of patients with DM/PM. Pericardial effusion was also reported in 66.7% of DM/PM patients. Patients with DM/PM had dilated right ventricle with elevated right ventricular systolic pressure | Poland |
| Zhong et al. [86] (2017) | 60 | DM/PM | Cross-sectional study | In a study of 60 PM/DM patients with preserved LVEF, speckle tracking echocardiography demonstrated subtle systolic dysfunction. The severity of cardiac involvement was related to the systemic disease burden | China |
| Guerra et al. [87] (2017) | 28 | DM/PM | Case control study | The authors reported a 4.9-fold higher risk of subclinical ventricular systolic dysfunction in IIM patients compared to healthy controls using speckle tracking echocardiography. The basal and mid-segments of the anterior, anterior-septal, and lateral wall of the left ventricle were most frequently involved. The presence of cardiac involvement was not associated with disease duration or disease activity | Italy |
| Liu et al. [88] (2022) | 46 | DM/PM | Observational study | Using speckle tracking echocardiography, it was noted that in patients with PM and DM, the myocardium at the base was more severely affected than at the apex. This pattern of basal weakness accurately differentiated myocardial involvement of DM and PM from acute viral myocarditis | China |
| Cardiac magnetic resonance | |||||
| Khoo et al. [89] (2019) | 19 |
DM (n = 4) PM (n = 4) IBM (n = 2) IMNM (n = 2) Myositis not otherwise specified (n = 4) Overlap myositis (n = 2) DM/SSc overlap (n = 1) |
Cohort study | Despite being asymptomatic for cardiac disease, almost 50% of patients with IIM had apparent cardiac involvement on CMR in the form of late gadolinium enhancement (LGE). Except for one patient, all patients showed varying degrees of cardiac fibrosis | Australia |
| Sun et al. [90] (2021) | 51 |
DM (n = 19) PM (n = 20) NM (n = 12) |
Observational study | This study demonstrated more severe LGE lesions in PM patients when compared to patients with DM. Patient with necrotizing myositis (NM) did not demonstrate late gadolinium enhancement | China |
| Kersten et al. [91] (2021) | 47 |
DM (n = 10) PM (n = 31) Other sub-forms of IIM (n = 6) |
Cohort study | Patients with IIM had lower myocardial deformation parameters (indicative of impaired myocardial function) when compared to healthy volunteers using cardiac magnetic resonance imaging. In this study there was no significant difference in the LVEF between patients and healthy volunteers, suggesting that change in myocardial deformation may precede changes in LVEF | Germany |
| Rosenbohm et al. [92] (2020) | 20 | IBM | Case series of 20 patients | In this case series of 20 patients with sporadic IBM, CMR demonstrated decreased left and right ventricular stroke volumes and an increased early myocardial enhancement when compared to controls. These changes were attributed to the hypertensive heart disease present in these patients. There was no statistical difference in LGE between patients and controls | Germany |
| Cardiac enzymes | |||||
| Lillekar et al. [93] (2018) | 123 |
DM (n = 39) PM (n = 34) ASS (n = 37) IMNM (n = 8) IIM-CTD overlap disease (n = 5) |
Cross sectional study | Cardiac troponin I (cTnI) levels were higher in patients with cardiac involvement, irrespective of disease activity. cTnI had the highest specificity (95%) and positive predictive value (62%) for detecting cardiac involvement, however, it lacked sensitivity. Cardiac troponin T (cTnT) correlated with the patient and evaluator global assessment and the quality of life as assessed by Health Assessment Questionnaire (HAQ) more strongly than cTnI and creatinine kinase (CK) | UK and Denmark |
| Sun et al. [90] (2021) | 51 |
DM (n = 19) PM (n = 20) IMNM (n = 12) |
Observational study | In a study of 51 IIM patients (19 patients with DM, 20 patients with PM and 12 patients with IMNM), patients with IMNM had very high serum markers of cardiac damage (CK-MB and cTnT) as compared to patients with PM and DM. The study showed that serum CK-MB and cTnT did not accurately reflect myocardial involvement in IIM, however, NT-pro BNP correlated positively with CMR finding of LGE. | China |