CARDIOVASCULAR JOURNAL OF AFRICA • Volume 34, No 3, July/August 2023 132 AFRICA Cardiovascular Topics Prognostic value of myocardial scar in ischaemic and non-ischaemic cardiomyopathy using cardiac magnetic resonance imaging Reem Laymouna, Eman El-Sharkawy, Salah El-Tahan, Mohamed El-Fiky Abstract Aim: The aim of this research was to evaluate the prognostic value of myocardial scar using cardiac magnetic resonance (CMR) imaging in patients with ischaemic cardiomyopathy (ICM) and non-ischaemic cardiomyopathy (NICM). Methods: One hundred and fifty-four patients with either ICM or NICM underwent CMR with late gadolinium enhancement sequences for assessment of left ventricular ejection fraction (LVEF), and detection and quantification of any myocardial scar using three methods: manual, number of segments involved, and percentage of scarred myocardium. Patients were followed up for at least six months for clinical cardiac events. Results: Patients were divided into two groups: group I, patients with ICM (58%) and group II, those with NICM (42%). Clinical presentation ranged from eventless (10%) to chest pain (18%), heart failure (15%), hospitalisation (35%), syncope (1%), ventricular tachycardia (< 1%) and cardiac arrest (< 1%). The scar mass was larger in size in group I (17 ± 15%) than in group II (8 ± 13%). A direct relationship was observed between scar size and event severity (p < 0.001). An inverse relationship between LVEF and event severity was found in group I (p < 0.001) but not in group II (p = 0.128). Conclusion: Myocardial scar size was a strong predictor of clinical outcome in both the ICM and NICM patients. LVEF was less reliable in predicting morbidity in cardiomyopathy patients. Keywords: ischaemic cardiomyopathy, non-ischaemic cardiomyopathy, cardiac MRI, myocardial scar Submitted 12/8/21; accepted 2/7/22 Published online 23/9/22 Cardiovasc J Afr 2023; 34: 132–139 www.cvja.co.za DOI: 10.5830/CVJA-2022-040 Cardiac muscle is a unique muscle type to perform a specific function: conducting electrical activity to both ventricles simultaneously to contract and relax in a synchronised manner, and pumping the blood to the whole body with a proper myocardial reserve to meet the varying physiological body situations.1 Therefore, evaluation of the myocardial muscle function using only left ventricular ejection fraction (LVEF) would be inaccurate. However, assessment of the myocardium on the tissue level to determine how healthy it is would be expected to provide more precise data regarding the ability to conduct, contract and relax properly. Tissue characterisation using cardiac magnetic resonance (CMR) provides more knowledge about the pathological processes occurring in different types of cardiomyopathy, hence, more prognostic information about each type of cardiomyopathy.2 Gadolinium contrast has a large molecular size that under normal conditions allows it to distribute in the extracellular space without penetrating the intact myocardial cells.3 However, in certain pathological circumstances, either the extracellular space may increase, such as in some non-ischaemic cardiomyopathy (NICM), or the myocardial cell membrane may be disrupted, as in ischaemic cardiomyopathy (ICM), leading to an increase in the amount of gadolinium distribution and gadolinium enhancement.4,5 Different types of cardiomyopathies exhibit different patterns of late enhancement,6,7 which open up entirely new possibilities in the differential diagnosis in patients with ventricular dysfunction. Late gadolinium enhancement (LGE) is based on differences in extracellular space in different areas of the myocardium, therefore it is more useful when the fibrosis is regional, for example, myocarditis, myocardial infarction scar, sarcoidosis and hypertrophic cardiomyopathy.6,7 Currently, there is no uniform approved way to quantify the myocardial scar size in cardiac magnetic resonance imaging (MRI) LGE sequences. Several methods have been used, such as number of segments with scar, manual planimetry of the enhanced myocardium, and automatic quantification using signal thresholding techniques to determine scar borders. For the last approach, most often the full width at half-maximum (FWHM) technique and two-standard deviations (2-SD) technique were used, as described originally by Kim et al.8 for myocardial infarction. Our study aim was to evaluate the prognostic value of myocardial scar using CMR on the clinical outcome in patients Cardiology and Angiology Department, Alexandria University, Alexandria, Egypt Reem Laymouna, PhD, r_hamdy10@alexmed.edu.eg Eman El-Sharkawy, MB BCh, MSc, PhD Salah El-Tahan, MB BCh, MSc, PhD Mohamed El-Fiky, MB BCh, MSc, PhD International Cardiac Centre Scan, Alexandria, Egypt Reem Laymouna, PhD Eman El-Sharkawy, MB BCh, MSc, PhD Salah El-Tahan, MB BCh, MSc, PhD
RkJQdWJsaXNoZXIy NDIzNzc=