Clinical and prognostic relevancy of left ventricular trabeculation assessed by cardiac magnetic resonance in patients with dilated cardiomyopathy.

BACKGROUND AND AIM: We sought to search for factors associated with the magnitude of trabeculation by cardiac magnetic resonance, and evaluate the impact of trabeculations on outcomes in patients with dilated cardiomyopathy (DCM). METHODS: We evaluated clinical profiles and outcomes of 276 subjects with DCM (age: 33.2 ± 13.3 years, 160 males). Trabeculation was quantified as trabeculated/total myocardial mass ratio (TM/M). Subjects were stratified into three subgroups (A, B, and C) according to the tertiles of rising TM/M values (33% ranges). A group of 30 healthy subjects served as controls. Patients were prospectively followed-up in search of major adverse cardiovascular events for 2.4 years on average (range 0.2-3.9 years). RESULTS: Dilated cardiomyopathy patients had more trabeculation than controls (27.1 ± 16.9% vs. 17.3 ± 8.1, p < 0.01). Group C subjects had lowest N-terminal pro-B-type natriuretic peptide (NT-proBNP) (1445 [984-3843] vs. 873 [440-2633] vs. 529 [206-1221] pg/mL, p < 0.01), higher ejection fraction (23.9 ± 10.4 vs. 25.0 ± 9.2 vs. 32.4 ± 2.7%, p = 0.03), and lower left ventricular mass index (LVMI) (91.3 ± 21.5 vs. 74.3 ± 31.1 vs. 55.7 ± 23.2 g/m2, p < 0.01). They also had fewer areas of late gadolinium enhancement (69 [46.3%] vs. 31 [38.2%] vs. 15 [32.6%], p = 0.01). Male sex (b = 0.21, SE = 0.13; p = 0.01), LVMI (b = -0.32, SE = 0.08, p < 0.01) and NT-proBNP (b = -0.05, SE = 0.02, p = 0.02) were independently related to TM/M. The magnitude of trabeculation was not a predictor of major adverse cardiovascular events. Prognosis was impacted by left ventricular end-diastolic volume index only (HR 2.538, 95% CI -1.734-3.218, p < 0.01). CONCLUSIONS: Trabeculation patterns relate to cardiac function and neurohormonal activation but not to survival.

The value of cardiac magnetic resonance and distribution of late gadolinium enhancement for risk stratification of sudden cardiac death in patients with hypertrophic cardiomyopathy.

BACKGROUND: The presence of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is associated with worse clinical outcome and the extent of LGE predicts the increased risk of sudden cardiac death (SCD). Limited data exist regarding the distribution of LGE. We attempted to verify whether the presence of LGE outside the interventricular insertion points carries additional risk for patients with HCM. METHODS: In this prospective study, 328 patients with HCM, who underwent cardiac magnetic resonance (CMR) were enrolled. Five major risk factors for SCD were assessed in all patients. The median follow-up was 37 months. RESULTS: LGE was detected in 226 (68.9%) patients. In 70 (21.3%) patients it was present only at the interventricular insertion points - LGE (+) group, while in 156 (47.6%) it was noted in other locations - LGE (++) group. Primary endpoint defined as SCD or appropriate implantable cardioverter-defibrillator intervention occurred in 14 (4.3%) patients, one in LGE (+) and 13 in LGE (++). In multivariable analysis including five traditional risk factors and left ventricular ejection fraction <50%, only the presence of LGE outside the insertion points was a significant predictor of SCD/aborted SCD (HR 10.01, 95% CI 1.21-83.86, p=0.033). The performance of the multivariable sudden cardiac death risk model was improved by the addition of LGE (++) to the traditional risk factors (likelihood ratio p=0.005). The Kaplan-Meier curves showed better event-free survival in the LGE (-) and LGE (+) patient groups compared to the LGE (++) group. CONCLUSIONS: In HCM patients, presence of LGE outside interventricular insertion points is associated with increased risk of sudden cardiac death or its equivalent as well as overall mortality. Cardiac fibrosis as a substrate for SCD in HCM may be identified on CMR and serve as an imaging biomarker of increased risk.