Myocardial Fibrosis Severity on Cardiac Magnetic Resonance Imaging Predicts Sustained Arrhythmic Events in Hypertrophic Cardiomyopathy

• Published in: Canadian journal of cardiology Vol. 29; no. 3; pp. 358 - 363
• Main Authors: Prinz, Christian, MD, Schwarz, Maria, Ilic, Ivan, MD, Laser, Kai Thorsten, MD, Lehmann, Roman, Prinz, Eva-Maria, Bitter, Thomas, MD, Vogt, Jürgen, MD, van Buuren, Frank, MD, Bogunovic, Nikola, MSc, Horstkotte, Dieter, MD, PhD, Faber, Lothar, MD, PhD
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.03.2013
• Subjects: Adult; Aged; Aged, 80 and over; Cardiomyopathy, Hypertrophic - complications; Cardiomyopathy, Hypertrophic - diagnosis; Cardiomyopathy, Hypertrophic - pathology; Cardiomyopathy, Hypertrophic - physiopathology; Cardiovascular; Cohort Studies; Contrast Media; Death, Sudden, Cardiac - etiology; Defibrillators, Implantable - statistics & numerical data; Female; Fibrosis; Follow-Up Studies; Gadolinium; Germany - epidemiology; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Multivariate Analysis; Myocardium - pathology; Predictive Value of Tests; Risk Assessment; Risk Factors; Sensitivity and Specificity; Severity of Illness Index; Tachycardia, Ventricular - diagnosis; Tachycardia, Ventricular - epidemiology; Tachycardia, Ventricular - etiology; Tachycardia, Ventricular - therapy; Treatment Outcome; Germany
• ISSN: 0828-282X; 1916-7075
• DOI: 10.1016/j.cjca.2012.05.004

Abstract Background The purpose of our study was to correlate the incidence of adequate implantable cardioverter-defibrillator (ICD) interventions in hypertrophic cardiomyopathy (HCM) patients with risk markers (RMs) for sudden cardiac death (SCD) plus myocardial fibrosis as detected by late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging. Methods In all, 87 patients with HCM underwent LGE-CMR imaging prior to ICD implantation, performed for secondary (n = 2; 2%) or primary SCD prophylaxis (n = 85; 98%). Fibrosis was graded with a 17-segment left ventricular model (0 = absent, 1 = point-shaped, 2 = limited to 1 left ventricular segment, 3 = involving ≥ 2 segments). During follow-up, ICD memories were read out by a physician blinded to the individual patient data. Results The number of RMs per patient was 1.9 ± 0.8. Myocardial fibrosis was present in 78 patients (90%); 26 (30%) had a fibrosis score of 3. During follow-up (3.5 ± 2.6 [range, 0.2-11.4 years]), 15 patients had 50 appropriate ICD interventions. Episodes of atrial fibrillation were found in 28 patients. Fibrosis severity correlated with occurrence of ventricular tachycardia (Cramér's V, or φc = 0.4, P < 0.001) and atrial fibrillation (φc = 0.6, P < 0.001). On multivariate regression analysis, an independent association between myocardial fibrosis (ß = 0.6, P < 0.01) and sustained ventricular tachycardia was found. Conclusions In HCM patients treated with ICD implantation because of a high SCD risk by traditional RM assessment, a high rate of arrhythmic events was observed during long-term follow-up. In a cohort of patients with clinical markers for high risk of SCD, severity of myocardial fibrosis as detected by an easy LGE-CMR scoring system was associated with future arrhythmic events and appropriate ICD therapies.