Objective criteria for septal fibrosis in non-ischemic dilated cardiomyopathy: validation for the prediction of future cardiovascular events

Journal of Cardiovascular Magnetic Resonance

Research

Mohammed Zahrani¹  Mahmoud Bokhari¹  Raymond Yee¹  Fahad Almehmadi¹  John Stirrat²  Yoko Mikami³  Aidan Cornhill³  Sebastien X. Joncas³  Andrew G. Howarth⁴  Bobak Heydari⁴  Naeem Merchant⁴  Carmen P. Lydell⁴  James A. White⁴ 

[1] Department of Medicine, Western University, London, ON, Canada;Robarts Research Institute, University of Western Ontario, London, ON, Canada;Stephenson Cardiac Imaging Centre, Libin Cardiovascular Institute of Alberta, University of Calgary, #0700, SSB, Foothills Medical Centre, 1403-29th St. NW, T2N2T9, Calgary, AB, Canada;Stephenson Cardiac Imaging Centre, Libin Cardiovascular Institute of Alberta, University of Calgary, #0700, SSB, Foothills Medical Centre, 1403-29th St. NW, T2N2T9, Calgary, AB, Canada;Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada;Department of Diagnostic Imaging, University of Calgary, Calgary, Canada;

关键词: Dilated cardiomyopathy;    Fibrosis;    Cardiovascular magnetic resonance;    Prognosis;   

DOI  :  10.1186/s12968-016-0300-z

 received in 2016-07-12, accepted in 2016-10-28,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundExpert subjective reporting of mid-wall septal fibrosis on late gadolinium enhancement (LGE) images has been shown to predict major cardiovascular outcomes in patients with non-ischemic dilated cardiomyopathy (NIDCM). This study aims to establish objective criteria for non-experts to report clinically relevant septal fibrosis and compare its performance by such readers versus experts for the prediction of cardiovascular events.MethodsLGE cardiovascular magnetic resonance (CMR) was performed in 118 consecutive patients with NIDCM (mean age 57 ± 14, 42 % female) and the presence of septal fibrosis scored by expert readers. CMR-naive readers performed signal threshold-based LGE quantification by referencing mean values of remote tissue and applying these to a pre-defined anatomic region to measure septal fibrosis. All patients were followed for the primary composite outcome of cardiac mortality or appropriate implantable cardioverter-defibrillator (ICD) therapy.ResultsThe mean LVEF was 32 ± 12 %. At a median follow-up of 1.9 years, 20 patients (17 %) experienced a primary composite outcome. Expert visual scoring identified 55 patients with septal fibrosis. Non-expert septal fibrosis quantification was highly reproducible and identified mean septal fibrosis burden for three measured thresholds as follows; 5SD: 2.9 ± 3.6 %, 3SD: 6.9 ± 6.3 %, and 2SD: 11.1 ± 7.5 % of the left ventricular (LV) mass, respectively. By ROC analysis, optimal thresholds for prediction of the primary outcome were; 5SD: 2.74 % (HR 8.7, p < 0.001), 3SD: 6.63 % (HR 5.7, p = 0.001) and 2SD: 10.15 % (HR 6.1, p = 0.001). By comparison, expert visual scoring provided a HR of 5.3 (p = 0.001). In adjusted analysis, objective quantification by a novice reader (>5SD threshold) was the strongest independent predictor of the primary outcome (HR 8.7) and provided improved risk reclassification beyond LVEF alone (NRI 0.54, 95 % CI 0.16–0.92, p = 0.005).ConclusionsNovice readers were able to achieve superior risk prediction for future cardiovascular events versus experts using objective criteria for septal fibrosis in patients with NIDCM. Patients with a septal fibrosis burden >2.74 % of the LV mass (>5SD threshold) were at a 9-fold higher risk of cardiac death or appropriate ICD therapy versus those not meeting this criteria. As such, this study validates reproducible criteria applicable to all levels of expertise to identify NIDCM patients at high risk of future cardiovascular events.

【 授权许可】

CC BY   
© The Author(s). 2016