The amount of late gadolinium enhancement outperforms current guideline-recommended criteria in the identification of patients with hypertrophic cardiomyopathy at risk of sudden cardiac death

Abstract

Background Identifying the patients with hypertrophic cardiomyopathy (HCM) in whom the risk of sudden cardiac death (SCD) justifies the implantation of a cardioverter-defibrillator (ICD) in primary prevention remains challenging. Different risk stratification and criteria are used by the European and American guidelines in this setting. We sought to evaluate the role of cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) in improving these risk stratification strategies. Methods We conducted a multicentric retrospective analysis of HCM patients who underwent CMR for diagnostic confirmation and/or risk stratification. Eligibility for ICD was assessed according to the HCM Risk-SCD score and the American College of Cardiology Foundation/American Heart Association (ACCF/AHA) algorithm. The amount of LGE was quantified (LGE%) and categorized as 0%, 0.1–10%, 10.1–19.9% and ≥ 20%. The primary endpoint was a composite of SCD, aborted SCD, sustained ventricular tachycardia (VT), or appropriate ICD discharge. Results A total of 493 patients were available for analysis (58% male, median age 46 years). LGE was present in 79% of patients, with a median LGE% of 2.9% (IQR 0.4–8.4%). The concordance between risk assessment by the HCM Risk-SCD, ACCF/AHA and LGE was relatively weak. During a median follow-up of 3.4 years (IQR 1.5–6.8 years), 23 patients experienced an event (12 SCDs, 6 appropriate ICD discharges and 5 sustained VTs). The amount of LGE was the only independent predictor of outcome (adjusted HR: 1.08; 95% CI: 1.04–1.12; p < 0.001) after adjustment for the HCM Risk-SCD and ACCF/AHA criteria. The amount of LGE showed greater discriminative power (C-statistic 0.84; 95% CI: 0.76–0.91) than the ACCF/AHA (C-statistic 0.61; 95% CI: 0.49–0.72; p for comparison < 0.001) and the HCM Risk-SCD (C-statistic 0.68; 95% CI: 0.59–0.78; p for comparison = 0.006). LGE was able to increase the discriminative power of the ACCF/AHA and HCM Risk-SCD criteria, with net reclassification improvements of 0.36 ( p = 0.021) and 0.43 ( p = 0.011), respectively. Conclusions The amount of LGE seems to outperform the HCM Risk-SCD score and the ACCF/AHA algorithm in the identification of HCM patients at increased risk of SCD and reclassifies a relevant proportion of patients. Electronic supplementary material The online version of this article (10.1186/s12968-019-0561-4) contains supplementary material, which is available to authorized users.

The Advantages of New Multimodality Imaging in Choosing the Optimal Management Strategy for Patients with Hypertrophic Cardiomyopathy

“…The role of LGE-CMR in improving risk stratification strategies in HCM patients was also studied by Freitas et al During a median follow-up of 3.4 years, their results suggest that the amount of LGE has an important prognostic value and that using LGE for sudden cardiac death risk stratification would correctly reclassify a considerable number of patients [80].…”

“…Cardiac magnetic resonance has an important role in diagnosis, risk stratification and management strategies of HCM patients, considering its high spatial resolution, better contrast between blood and myocardium, accurate volumetric evaluation of cardiac chambers and also the fact that it is not influenced by the chest anatomy and associated pulmonary parenchymal pathologies, compared to echocardiography. It is considered the gold standard for the evaluation of wall thickness and chamber volumes, allowing a more accurate characterization of heart volumes and functions, tissue morphology and extension of myocardial hypertrophy [80,81]. It is an excellent imaging technique to detect apical aneurysms, clots or papillary muscle.…”

Cardiovascular Magnetic Resonance for the Differentiation of Left Ventricular Hypertrophy

“…Although not yet incorporated into risk calculators, it is clear that LGE in HCM is prognostic and may even outperform and increase the discriminative power of current SCD risk scores [49].…”

“…The presence and extent of LGE is also independently associated with an increased risk of SCD and adverse outcomes (including development of heart failure), particularly if > 15% of total LV mass [ 43 , 45 •, 46 – 48 ]. Although not yet incorporated into risk calculators, it is clear that LGE in HCM is prognostic and may even outperform and increase the discriminative power of current SCD risk scores [ 49 ].…”

Elevated level of N-terminal pro B-type natriuretic peptide is associated with myocardial fibrosis in hypertrophic cardiomyopathy patients with preserved ejection fraction

“…Extensive late gadolinium enhancement (LGE) imaging on cardiovascular magnetic resonance (CMR) is currently recognized as the gold standard for the identi cation of left ventricular (LV) focal replacement brosis [7]. Data currently suggest that LGE is highly promising in predicting SCD and progression to heart failure in HCM [8,9]. However, the administration of contrast agents needed for this technology may result in systemic nephrogenic sclerosis [10].…”