What is the clinical evidence from this study?

Study design: Case-Control. Population: Hypertrophic cardiomyopathy (n=72). Intervention: 2-dimensional speckle tracking echocardiography (2D-STE) vs. Healthy subjects. Primary outcome: Global peak systolic longitudinal strain of the subendocardial layer (p=<0.001).

August 2, 2017Open Access

Left ventricular systolic function changes in hypertrophic cardiomyopathy patients detected by the strain of different myocardium layers and longitudinal rotation

Q: What are the key findings of this study?

Compared to healthy subjects, hypertrophic cardiomyopathy patients exhibited significantly reduced global peak systolic longitudinal strain in the subendocardial layer (-16.75% vs -23.99%) and clockwise longitudinal rotation despite normal ejection fraction.

JHJun HuangGuangdong Medical College ZYZi-Ning YanSecond Affiliated Hospital of Jilin University LFLi FanTufts Medical Center

Key Result

Compared to healthy subjects, hypertrophic cardiomyopathy patients exhibited significantly reduced global peak systolic longitudinal strain in the subendocardial layer (-16.75% vs -23.99%) and clockwise longitudinal rotation despite normal ejection fraction.

Study Design

Type

Case-Control (n=72)

Multicenter

Structured PICO

Does 2-dimensional speckle tracking echocardiography detect impaired left ventricular longitudinal systolic function and abnormal longitudinal rotation in patients with hypertrophic cardiomyopathy compared to healthy controls?

Population

72 subjects: 36 patients with non-obstructive hypertrophic cardiomyopathy (HCM) with septal wall hypertrophy (excluding apical HCM and LBBB) and 36 age- and gender-matched healthy controls.

Intervention

2-dimensional speckle tracking echocardiography (2D-STE) to measure peak systolic longitudinal strain of subendocardial, midmyocardial, and subepicardial layers, and longitudinal rotation.

Comparator

Healthy control subjects evaluated with the same echocardiographic methods.

Outcome

Peak systolic longitudinal strain of the subendocardial, midmyocardial, and subepicardial layers, and longitudinal rotation degrees.surrogate

2D speckle tracking echocardiography reveals that longitudinal systolic function is impaired across all myocardial layers in HCM patients, even when left ventricular ejection fraction is normal.

Main Result

Absolute Event Rate: -16.75% vs -23.99%

p-value: p=<0.001

Limitations

High standard deviations are indicative of the high variability with this technique - when narrow ROI is chosen to try and assess myocardial layers, higher strain values are recorded and more noise is introduced.

Abstract

BACKGROUND: Impairment of left ventricular (LV) longitudinal function has an important role in hypertrophic cardiomyopathy (HCM). This research investigated an association between the longitudinal strain of different myocardial layers, longitudinal rotation and the LV systolic function of HCM patients. METHODS: The research was performed on 36 HCM patients and 36 healthy subjects. The peak systolic longitudinal strain of the subendocardial, midmyocardial, and subepicardial layers was measured using 2-dimensional speckle tracking echocardiography (2D-STE). The apical long-axis and 4- and 2- chamber views were acquired via 2D Doppler echocardiography. The curve of the longitudinal rotation was traced at 17 timepoints in the analysis of 2 cardiac cycles. RESULTS: Compared with healthy subjects, in HCM patients regional LV peak systolic longitudinal strain was less, not only in hypertrophied LV myocardium, but also in non-hypertrophied myocardium. The rotational degrees of the midmyocardial-septal, apex, and lateral wall of HCM patients were significantly different from that of normal subjects, as follows. In HCM patients, clockwise longitudinal rotation was found. The interventricular septum thickness at end-diastole positively correlated with the peak longitudinal systolic strain of the subendocardial, the midmyocardial, and the subepicardial layers. The area under ROC curve values for subendocardial, midmyocardial and subepicardial layers in HCM patients were 0.923, 0.938, 0.948. CONCLUSION: In HCM patients, the longitudinal function was damaged, even with normal LV ejection fraction. The peak longitudinal systolic strain of the subendocardial, midmyocardial, and subepicardial layers, and the longitudinal rotation detected by 2D-STE, are very sensitive predictors of systolic function in patients with HCM.

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