tests techniques for the population with DCM. EMB and ICA has higher rates of complications. B3. Diagnostic performance Accuracy of CMR for diagnosing DCM N=136 K=1 diagnostic accuracy study Sensitivity = 0.83 (0.71, 0.92) Specificity = 0.93 (0.85, 0.97) CMR is reasonably good at identifying DCM, when compared with clinical diagnosis and EMB. However, these findings were in studies that included patients other than those with an inconclusive echocardiogram. Moderate ⨁⨁⨁⨀ Accuracy of CMR at ICM from NIDCM K=8 diagnostic accuracy studies (K=6 vs ICA, K=2 vs clinical diagnosis) Sensitivity = 0.68–1.00 Specificity = A high proportion of those patients with NIDCM may avoid ICD insertion if imaged with CMR. Low ⊕⊕⨀⨀ to High ⊕⊕⊕⊕ B3. Diagnostic performance; B4.2. Prognosis or predisposition Accuracy of CMR vs CTCA, SPECT, or stress echo or contrast echo K=1 diagnostic accuracy study; 2 prognostic studies Only very limited evidence compared with CTCA Contradictory evidence compared with SPECT No evidence compared with stress or contrast echocardiography. Conclusions on the comparative accuracy or prognostic benefit of CMR vs alternative techniques cannot be made. Very low ⊕⨀⨀⨀ B5.1. Therapeutic efficacy Diagnostic yield of CMR in those classified as having idiopathic DCM N=102 K=1 comparative diagnostic yield study CMR identified aetiologies in 4/102 patients. 3/4 aetiologies were not identified by any other further test. 1/4 patients were also identified by EMB. CMR provides unique information, identifying a small number of cases who would otherwise be classified as having idiopathic NIDCM. None of the other tests could be replaced by CMR, as each reported unique aetiologies. Very low ⊕⨀⨀⨀ B4.2. Prognosis or predisposition LGE-CMR for prognosis in those with K=30 prospective or retrospective cohort All-cause mortality RR = 2.47 (95%CI 1.63, 3.74) Cardiac deaths RR = 3.21 (95%CI 1.79, Those with signs of scarring or inflammation on LGE-CMR had worse cardiac outcomes than those without signs, and were more likely to have Low ⊕⊕⨀⨀ to Moderate
NIDCM studies 5.76) Any cardiac event RR = 3.71 (95%CI 2.29, 6.04) an ICD implanted and to have an appropriate ICD shock. ⊕⊕⊕⨀ B5.1. Therapeutic efficacy Effect of CMR on device and surgery for NIDCM N=488 K=1 cohort study In those patients scheduled for devices, 21/72 (29.2%) avoided implantation following CMR imaging. In those not scheduled for devices, 20/375 (5.3%) had one implanted after CMR imaging. In those scheduled for surgery, 13/20 (65%) avoided surgery after CMR. In those not scheduled for surgery, 7/427 (1.6%) underwent surgery after CMR. CMR is effective at reducing the proportion of patients who receive devices or surgery for treatment of CM, compared with what is done currently in Australia. Only a small proportion of patients who would otherwise not receive devices or surgery had their treatment plan amended following investigation with CMR. Appropriate avoidance of invasive therapies would result in superior safety outcomes. Moderate ⊕⊕⊕⨀ B5.2. Therapeutic effectiveness of for myocarditis N=719 K=8 RCTs Mean LVEF difference = 7.36% (95%CI 4.94, 9.79), favouring corticosteroids over no corticosteroids after months No significant difference in mortality Treatment specific for myocarditis may improve cardiovascular functioning, compared with general treatment for HF symptoms. Moderate ⊕⊕⊕⨀ of for ICM N=93,553 K=100 RCTs CABG reduces the risk of death, myocardial infarction and subsequent revascularisation, compared with medical treatment alone. There were no data specific to patients who were negative for scarring or inflammation using LGE-CMR. Correct identification of ICM is likely to reduce patient cardiac deaths and other outcomes. However, the impact of an incorrect diagnosis of NIDCM in those who are LGE– is unknown. Low ⊕⊕⨀⨀ CABG = coronary artery bypass grafting; CI = confidence interval; CM = cardiomyopathy; CMR = cardiac magnetic resonance (imaging); DCM = dilated cardiomyopathy; CTCA = computed tomography coronary 3