[A comparative study of cardiac magnetic resonance characteristics and prognosis between dilated cardiomyopathy with left ventricular hypertrabeculation and isolated dilated cardiomyopathy].

Objective

To compare the differences in cardiac magnetic resonance (CMR) characteristics between dilated cardiomyopathy (DCM) patients accompanied by left ventricular hypertrabeculation and those with isolated DCM, and to investigate the impact of left ventricular hypertrabeculation on the prognosis of DCM patients.

Methods

This single-center retrospective cohort study enrolled DCM patients who were admitted to Peking Union Medical College Hospital from November 2016 to March 2025. Basic clinical data and CMR parameters of the patients were collected. According to the results of echocardiography, the patients were divided into the isolated DCM group and the DCM with left ventricular hypertrabeculation group. Patients were followed up through outpatient visits or telephone calls. The composite endpoint consisting of cardiovascular death, heart failure hospitalization, and malignant arrhythmia events (ventricular fibrillation, sustained ventricular tachycardia) was used as the outcome event. Univariate and multivariate Cox proportional hazards regression models were used to analyze the risk factors affecting the prognosis of DCM patients. Survival analysis was performed using Kaplan-Meier curves, and the log-rank test was used to compare the differences in the incidence of outcome events between groups. Subgroup analysis was conducted according to the range of left ventricular late gadolinium enhancement (LGE) (≥7.5% and <7.5%).

Results

A total of 114 DCM patients were enrolled, including 65 in the isolated DCM group and 49 in the DCM with left ventricular hypertrabeculation group. In the isolated DCM group, the patients had an age of (44±16) years, with 44 males (68%); in the DCM with left ventricular hypertrabeculation group, the patients had an age of (40±17) years, with 32 males (65%). Regarding echocardiographic parameters, there were no statistically significant differences in left ventricular ejection fraction ((34±8)% vs. (32±11)%) and left ventricular end-diastolic diameter ((65±8) mm vs. (66±8) mm) between the isolated DCM group and the DCM with left ventricular hypertrabeculation group (both P>0.05). In terms of CMR characteristics, the left ventricular end-diastolic volume (126 (105, 158) ml vs. 146 (114, 185) ml), left ventricular global longitudinal strain ((-8.15±3.17)% vs. (-8.56±3.76)%), and left ventricular LGE extent (11.4 (4.3, 26.6)% vs. 12.3 (5.4, 20.2)%) in the isolated DCM group were lower than those in the DCM with left ventricular hypertrabeculation group, while the left ventricular ejection fraction was higher than that in the DCM with left ventricular hypertrabeculation group (29 (23, 35)% vs. 27 (20, 39)%). However, there were no statistically significant differences in the above CMR parameters between the two groups (all P>0.05). For prognosis, during a follow-up of 368 (146, 652) days, 25 patients (22%) experienced outcome events, including 4 cases (4%) of cardiovascular death, 22 cases (19%) of heart failure hospitalization, and 1 case (1%) of malignant arrhythmia. Cox regression analysis showed that left ventricular hypertrabeculation was not associated with the occurrence of outcome events in DCM patients (HR=0.682, 95%CI 0.301-1.540, P=0.358), while left ventricular LGE extent was associated with the prognosis of DCM patients (HR=6.589, 95%CI 1.064-40.794, P=0.043). Kaplan-Meier curves showed that there was no statistically significant difference in the cumulative incidence of outcome events between the isolated DCM group and the DCM with left ventricular hypertrabeculation group (log-rank P=0.355); however, DCM patients with left ventricular LGE extent ≥7.5% had a higher risk of adverse prognosis than those with left ventricular LGE extent <7.5% (log-rank P=0.032).

Conclusion

There are no significant differences in CMR characteristics between DCM patients with left ventricular hypertrabeculation and those with isolated DCM, and left ventricular hypertrabeculation had no impact on the prognosis of DCM patients. In contrast, left ventricular LGE extent was a risk factor affecting the prognosis of DCM patients.