Global longitudinal strain evaluated by speckle-tracking echocardiography as a surrogate marker for predicting replacement fibrosis detected by magnetic resonance-late gadolinium enhancement in patients with nonischemic cardiomyopathy

Prognostic Relevance of Left Ventricular Global Longitudinal Strain in Patients With Heart Failure and Reduced Ejection Fraction

Patients with heart failure (HF) and reduced ejection fraction (HFrEF) are complex patients who often have a high prevalence of co-morbidities and risk factors. In the present study, we investigated the prognostic significance of left ventricular (LV) global longitudinal strain (GLS) along with important clinical and echocardiographic variables in patients with HFrEF. Patients who had a first echocardiographic diagnosis of LV systolic dysfunction, defined as LV ejection fraction ≤45%, were selected. The study population was subdivided into 2 groups based on a spline curve analysis derived optimal threshold value of LV GLS (≤10%). The primary end point was occurrence of worsening HF, whereas the composite of worsening HF and all-cause death was chosen for the secondary end point. A total of 1,873 patients (mean age 63 ± 12 years, 75% men) were analyzed. During a median follow-up of 60 months (interquartile range 27 to 60 months), 256 patients (14%) experienced worsening HF and the composite end point of worsening HF and all-cause mortality occurred in 573 patients (31%). The 5-year event-free survival rates for the primary and secondary end point were significantly lower in the LV GLS ≤10% group compared with the LV GLS >10% group. After adjustment for important clinical and echocardiographic variables, baseline LV GLS remained independently associated with a higher risk of worsening HF (hazard ratio 0.95, 95% confidence interval 0.90 to 0.99, p = 0.032) and the composite of worsening HF and all-cause mortality (hazard ratio 0.94, 95% confidence interval 0.90 to 0.97, p = 0.001). In conclusion, baseline LV GLS is associated with long-term prognosis in patients with HFrEF, independent of various clinical and echocardiographic predictors.

Endocardial versus whole-myocardial tracking global longitudinal strain analysis in patients with hypertrophic cardiomyopathy: A preliminary comparative study

BACKGROUND AND OBJECTIVES

We investigated whether the feasibility of left ventricular (LV) global longitudinal strain (GLS) in hypertrophic cardiomyopathy (HCM) varies according to the methodology (e.g. endocardial vs. whole myocardial tracking techniques).

METHODS

We retrospectively analyzed 111 consecutive patients with HCM (median age, 58 years; male, 68.5%) who underwent both transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (apical 29.7%, septal 33.3%, and diffuse or mixed 37.0%). TTE-whole myocardial and TTE-endocardial GLS were measured and compared in terms of association with late gadolinium enhancement (LGE) extent and discrimination performance for extensive LGE (>15% of the LV myocardium).

RESULTS

Although TTE-whole myocardial and TTE-endocardial GLS were significantly correlated, absolute TTE-endocardial GLS values (19.3 [16.2-21.9] %) were higher than TTE-whole myocardial GLS values (13.3[10.9-15.6] %, p<0.001). Both TTE-derived GLS parameters were significantly correlated with the LGE extent and independently associated with extensive LGE (odds ratio [OR] 1.30, p = 0.022; and OR 1.24, p = 0.013, respectively). Discrimination performance for extensive LGE was comparable between TTE-whole myocardial and TTE-endocardial GLS (area under the curve [AUC], 0.747 and 0.754, respectively, pdifference = 0.610). However, among patients with higher LV mass index (>70 g/m2), only TTE-whole myocardial GLS correlated with LGE extent and was independently associated with extensive LGE (OR 1.35, p = 0.042), while TTE-endocardial GLS did not. Additionally, TTE-whole myocardial GLS had better discrimination performance for extensive LGE than TTE-endocardial GLS (AUC, 0.705 and 0.668, respectively, pdifference = 0.006).

CONCLUSION

TTE-derived GLS using either the endocardial or whole myocardial tracking technique is feasible in patients with HCM. However, in those with severe hypertrophy, TTE-whole myocardial GLS is better than TTE-endocardial GLS.

Multimodality imaging in acute myocarditis

The diagnosis of acute myocarditis often involves several noninvasive techniques that can provide information regarding volumes, ejection fraction, and tissue characterization. In particular, echocardiography is extremely helpful for the evaluation of biventricular volumes, strain and ejection fraction. Cardiac magnetic resonance, beyond biventricular volumes, strain, and ejection fraction allows to characterize myocardial tissue providing information regarding edema, hyperemia, and fibrosis. Contemporary cardiac computed tomography angiography (CCTA) can not only be extremely important for the assessment of coronary arteries, pulmonary arteries and aorta but also tissue characterization using CCTA can be an additional tool that can explain chest pain with a diagnosis of myocarditis.

Association Between Echocardiographic Non-invasive Myocardial Work Indices and Myocardial Fibrosis in Patients With Dilated Cardiomyopathy

Objectives: To analyze the association between global myocardial work indices evaluated by non-invasive left ventricular (LV) pressure-strain loop (PSL) and LV myocardial fibrosis in patients with dilated cardiomyopathy (DCM).

Methods: A total of 57 patients with DCM were included in this prospective study. Global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE) and global longitudinal strain (GLS) were measured using LVPSL. LV volumes and LV ejection fraction (LVEF) were evaluated using cardiac magnetic resonance imaging (CMRI), LV myocardial fibrosis was estimated at CMRI by qualitative assessment of late gadolinium enhancement (LGE). According to the CMRI, the studied population was divided into two groups, namely: patients without LGE (LGE-) and patients with LGE (LGE+).

Results: The LGE+ group presented with increased age, LV end systolic volume (LVESV) index and reduced GWI, GCW, GWE, GLS, CMRI-derived LVEF (LVEF_CMRI), the differences between the two groups were statistically significant (P < 0.05). After correcting for age and LVESV index, LVEF_CMRI, GLS, GWI, GCW, and GWE retained independent associations with LV myocardial fibrosis. According to receiver operating characteristics (ROC) analysis, LVEF_CMRI, and GCW showed larger AUC and higher accuracy, sensitivity, and specificity than GLS, the accuracy of predicting LV myocardial fibrosis ranged from high to low as: LVEF_CMRI, GCW, GWE, GWI, and GLS.

Conclusions: LVEF_CMRI, GWI, GCW, GWE, and GLS remained significant predictors of LV myocardial fibrosis. LVEF_CMRI, and GCW appeared to better predict LV myocardial fibrosis compared with GLS.