Value of Speckle Tracking-Based Deformation Analysis in Screening Relatives of Patients With Asymptomatic Dilated Cardiomyopathy.

Objectives: This study sought to investigate the prevalence of systolic dysfunction using global longitudinal strain (GLS) and its prognostic value in relatives of dilated cardiomyopathy (DCM) patients that had normal left ventricular ejection fraction (LVEF).

Background: DCM relatives are advised to undergo cardiac assessment including echocardiography, irrespective of the genetic status of the index patient. Even though LVEF is normal, the question remains whether this indicates absence of disease or simply normal cardiac volumes. GLS may provide additional information regarding (sub)clinical cardiac abnormalities and thus allow earlier disease detection.

Methods: A total of 251 DCM relatives and 251 control subjects with a normal LVEF (≥55%) were screened. Automated software measured the GLS on echocardiographic 2-, 3-, and 4-chamber views. The cutoff value for abnormal strain was >-21.5. Median follow-up was 40 months (interquartile range: 5 to 80 months). Primary outcome was the combination of death and cardiac hospitalization.

Results: A total of 120 relatives and 83 control subjects showed abnormal GLS (48% vs. 33%, respectively; p < 0.001). Abnormal GLS was independently associated with DCM relatives and cardiovascular risk factors, rather than genetic mutations. Subjects with abnormal GLS had more frequent cardiac hospitalizations and a higher mortality as compared with subjects with normal GLS (hazard ratio: 3.29; 95% confidence interval: 1.58 to 6.87; p = 0.001). Additionally, follow-up LVEF was measured in a subset of relatives, and it decreased significantly in those with abnormal as compared with normal GLS (p = 0.006).

Conclusions: Relatives of DCM patients had a significantly higher prevalence of systolic dysfunction detected by GLS despite normal LVEF compared with control subjects, independent of age, sex, comorbidities, and genotype. Abnormal GLS was associated with LVEF deterioration, cardiac hospitalization, and death.