Abstract 2812: Accuracy of Delayed Hyper-Enhancement Cardiac Magnetic Resonance Imaging in Patients with Endomyocardial Biopsy Positive Amyloidosis: A Multimodality Imaging Study
In patients with suspected cardiac amyloidosis (CA), endomyocardial biopsy (EMB) provides definitive diagnosis. On delayed hyper-enhancement cardiac magnetic resonance (DHE-CMR), CA has a characteristic diffuse enhancement of the subendocardium extending to adjacent myocardium. We sought to determine the accuracy of DHE-CMR, as compared to standard noninvasive parameters, in the diagnosis of patients with suspected CA who underwent EMB. A total of 37 consecutive patients (mean age 60 years, 70 % men, 57 % with NYHA class > 2) with suspected CA underwent electrocardiography (ECG), transthoracic echocardiography (TTE), DHE-CMR (Siemens 1.5 T scanner, Erlangen, Germany) and EMB between 1/05 and 4/08. Low voltage on ECG was defined as the sum of S wave in lead V1 + R wave in lead V5 or V6 < 15mm. Standard TTE (including tissue Doppler) parameters and myocardial performance index (MPI) [(isovolumic contraction time + isovolumic relaxation time)/ejection time] were recorded. CMR was considered positive in the presence of DHE of the subendocardium extending to the adjacent myocardium. Fifteen patients had EMB-positive CA, while 22 had negative EMB. Using EMB as the gold standard, there was 1 false-positive and 1 false-negative CMR. Sensitivity and specificity of DHE-CMR for CA was 93% and 95%, and, positive predictive value (PV) and negative PV of DHE-CMR in the diagnosis of CA were 93 % and 95 % respectively. Logistic regression analysis demonstrating the association between EMB-positive CA and various noninvasive parameters is shown in the Table⇓. DHE-CMR is highly accurate in noninvasive diagnosis of EMB-positive CA as compared to standard ECG and TTE criteria. Incremental prognostic value of DHE-CMR in CA for clinical outcomes needs to be determined.