Abstract 4187: Identification of Late Gadolinium Enhancement by Contrast-Enhanced Magnetic Resonance Imaging as a Major Risk Factor for Sudden Death in Hypertrophic Cardiomyopathy
Background: Myocardial late gadolinium enhancement (LGE) on Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI) of patients (pts) with hypertrophic cardiomyopathy (HCM) may indicate intra-myocardial fibrosis. We explored whether the presence and extent of LGE on CE-MRI among pts with HCM predicted ventricular arrhythmogenicity, and decreased survival. Methods: 424 HCM pts [age = 55 ± 16 years (range 2 – 90), 41% females], without prior history of septal ablation/myectomy, underwent CE-MRI (GE 1.5T) during a 6-year period. We compared the presence and amount of LGE with degree of ventricular ectopy on Holter ECG (available in 220 pts) recorded during the same time period of the CE-MRI. All cause death and appropriate, VF-terminating ICD therapies were then recorded during a mean follow-up of 34 ± 14 months (range 7 – 85). Results: 239 pts (56%) had LGE ranging from 0.4 – 65% of the myocardium. LGE -positive pts were more likely to have non-sustained ventricular tachycardia on Holter ECG [34/126 (27%) vs 8/94 (8.5%), p < 0.001], and had more total ventricular extrasystoles/24 hours (700 ± 2080 vs 103 ± 460, p < 0.001). During follow-up, 7 pts died and 4 received appropriate ICD discharges (9.7% of 41 pts with ICD). All 11 pts were LGE-positive. Event free survival was excellent (100%) in pts without LGE, and lower (95.4%) in pts with LGE (log rank, p < 0.002). Multivariate analysis (adjusting for age, gender, morphologic and functional data, and comorbidities) identified LGE involving ≥ 5% of LV mass (p=0.03, present in 7/11 pts with events), septal thickness≥30mm (p=0.03), and atrial fibrillation (p=0.02) as independent predictors of death or appropriate ICD discharges. Conclusions : In pts with HCM, LGE by CE-MRI was strongly associated with surrogates of arrhythmia and was independently associated with subsequent death and/or ICD discharge. If replicated, LGE may be considered a major risk for sudden death in HCM.
Abstract 695: Significant Hypertrophy and Reduced Systolic Function Predict Intramyocardial Fibrosis in Patients with Hypertrophic Cardiomyopathy Undergoing Cardiac Magnetic Resonance Imaging
Background: Contrast enhanced magnetic resonance imaging (CE-MRI) is a useful tool to define cardiac morphology, systolic function, and the presence of late gadolinium enhancement (LGE). In patients (pts) with hypertrophic cardiomyopathy (HCM), LGE may represent intra-myocardial fibrosis. We explored the association between left ventricular (LV) morphology and function to the presence and amount of LGE in pts with HCM. Methods: 424 HCM pts (age = 55 ± 16 years, 41% females), without prior history of septal ablation/myectomy, underwent CE-MRI (GE 1.5T) during a 6-year period. LV volumes, diameter, ejection fraction (EF), septal shape and thickness, and the presence of obstructive physiology were assessed from standard steady state free precession pulse sequences. The presence and amount of LGE were traced from a dynamic post contrast inversion recovery pulse sequence. Morphologic and functional findings were then compared with presence and amount of LGE. Results: Over half of the pts [239/424 (56%)] had LGE, most commonly localizing to RV insertion points [174/239 pts, (73%)]. The extent of LGE ranged from 0.4–65% of LV mass. Univariate (morphologic) predictors of LGE were: reverse curve septal shape [OR = 7.8, (95% CI, 3.9–15.6)], septal thickness ≥ 16 mm (OR = 4.5, 2.4–8.2), LV mass ≥ 150 grams (OR = 2.6, 1.7–3.8)], LVEF<50% (OR = 4.6, 1.3–16), and presence of obstructive physiology (OR = 1.8, 1.02–3). The percentage of LV mass involved with LGE increased with higher LV mass, increased septal wall thickness, and decreasing LVEF (Spearman rank = 0.2– 0.4, p<0.0001 for all). Multivariate analysis (adjusting for all morphologic and functional parameters) showed that septal thickness ≥ 16mm (p = 0.0001), LV mass ≥ 150 grams (p = 0.01) and LVEF < 50% (p = 0.02) were independent predictors of LGE on CE-MRI. Conclusions: LGE, as determined by CE-MRI, was seen in over half of the patients with HCM. Decreased LVEF, increased septal thickness, and increased LV mass were associated with the presence of LGE. The clinical and prognostic impact of these morphological features warrants further investigation.
Comparison between three‐dimensional angiographic reconstruction and intravascular ultrasound: Imaging of the left main coronary artery
Characteristics and Clinical Significance of Late Gadolinium Enhancement by Contrast-Enhanced Magnetic Resonance Imaging in Patients With Hypertrophic Cardiomyopathy
Background— Myocardial late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (CE-MRI) of patients with hypertrophic cardiomyopathy (HCM) has been suggested to represent intramyocardial fibrosis and, as such, an adverse prognostic risk factor. We evaluated the characteristics of LGE on CE-MRI and explored whether LGE among patients with HCM was associated with genetic testing, severe symptoms, ventricular arrhythmias, or sudden cardiac death (SCD). Methods and Results— Four hundred twenty-four patients with HCM (age=55±16 years [range 2 to 90], 41% females), without a history of septal ablation/myectomy, underwent CE-MRI (GE 1.5 Tesla). We evaluated the relation between LGE and HCM genes status, severity of symptoms, and the degree of ventricular ectopy on Holter ECG. Subsequent SCD and appropriate implanted cardioverter defibrillator (ICD) therapies were recorded during a mean follow-up of 43±14 months (range 16 to 94). Two hundred thirty-nine patients (56%) had LGE on CE-MRI, ranging from 0.4% to 65% of the left ventricle. Gene-positive patients were more likely to have LGE ( P <0.001). The frequencies of New York Heart Association class ≥3 dyspnea and angina class ≥3 were similar in patients with and without LGE (125 of 239 [52%] versus 94 of 185 [51%] and 24 of 239 [10%] versus 18 of 185 [10%], respectively, P =NS). LGE-positive patients were more likely to have episodes of nonsustained ventricular tachycardia (34 of 126 [27%] versus 8 of 94 [8.5%], P <0.001), had more episodes of nonsustained ventricular tachycardia per patient (4.5±12 versus 1.1±0.3, P =0.04), and had higher frequency of ventricular extrasystoles/24 hours (700±2080 versus 103±460, P =0.003). During follow-up, SCD occurred in 4 patients, and additional 4 patients received appropriate ICD discharges. All 8 patients were LGE positive (event rate of 0.94%/y, P =0.01 versus LGE negative). Two additional heart failure-related deaths were recorded among LGE-positive patients. Univariate associates of SCD or appropriate ICD discharge were positive LGE ( P =0.002) and presence of nonsustained ventricular tachycardia ( P =0.04). The association of LGE with events remained significant after controlling for other risk factors. Conclusions— In patients with HCM, presence of LGE on CE-MRI was common and more prevalent among gene-positive patients. LGE was not associated with severe symptoms. However, LGE was strongly associated with surrogates of arrhythmia and remained a significant associate of subsequent SCD and/or ICD discharge after controlling for other variables. If replicated, LGE may be considered an important risk factor for sudden death in patients with HCM.