Impact of global longitudinal strain on left ventricular remodeling and clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI)

Myocardial Blood Flow Reserve, Microvascular Coronary Health, and Myocardial Remodeling in Patients With Aortic Stenosis

BACKGROUND

Coronary microvascular function and hemodynamics may play a role in coronary circulation and myocardial remodeling in patients with aortic stenosis (AS). We aimed to evaluate the relationship between myocardial blood flow and myocardial function in patients with AS, no AS, and aortic valve sclerosis.

METHODS AND RESULTS

We included consecutive patients who had resting transthoracic echocardiography and clinically indicated positron emission tomography myocardial perfusion imaging to capture their left ventricular ejection fraction, global longitudinal strain (GLS), and myocardial flow reserve (MFR). The primary outcome was major adverse cardiovascular event (all-cause mortality, myocardial infarction, or late revascularization). There were 2778 patients (208 with aortic sclerosis, 39 with prosthetic aortic valve, 2406 with no AS, and 54, 49, and 22 with mild, moderate, and severe AS, respectively). Increasing AS severity was associated with impaired MFR (P<0.001) and GLS (P<0.001), even when perfusion was normal. Statistically significant associations were noted between MFR and GLS, MFR and left ventricular ejection fraction, and MFR and left ventricular ejection fraction reserve. After a median follow-up of 349 (interquartile range, 116-662) days, 4 (7.4%), 5 (10.2%), and 6 (27.3%) patients experienced a major adverse cardiovascular event in the mild, moderate, and severe AS groups, respectively. In a matched-control analysis, patients with mild-to-moderate AS had higher rates of impaired MFR (52.9% versus 39.9%; P=0.048) and major adverse cardiovascular event (11.8% versus 3.0%; P=0.002).

CONCLUSIONS

Despite lack of ischemia, as severity of AS increased, MFR decreased and GLS worsened, reflecting worse coronary microvascular health and myocardial remodeling. Positron emission tomography-derived MFR showed a significant independent correlation with left ventricular ejection fraction and GLS. Patients with prosthetic aortic valve showed a high prevalence of impaired MFR.

Global longitudinal strain in long-term risk prediction after acute coronary syndrome: an investigation of added prognostic value to ejection fraction

AIMS

This study aimed to investigate the additional value of global longitudinal strain (GLS) on top of left ventricular ejection fraction (LVEF) in long-term risk prediction of combined death and heart failure (HF) re-hospitalization after acute coronary syndrome (ACS).

METHOD AND RESULTS

This retrospective study included patients admitted with ACS between 2008 and 2014 from the three participating university hospitals. LVEF and GLS were assessed at a core lab from images acquired during the index hospital stay. Their prognostic value was studied with the Cox proportional hazards model (median follow-up 6.2 years). A nested model comparison was performed with C-statistics. A total of 941 patients qualified for multivariable analysis after multiple imputation of missing baseline covariables. The combined outcome was reached in 17.7% of the cases. Both GLS and LVEF were independent predictors of the combined outcome, hazard ratio (HR) 1.068 (95% CI 1.017-1.121) and HR 0.980 (95% CI 0.962-0.998), respectively. The C-statistic increased from 0.742 (95% CI 0.702-0.783) to 0.749 (95% CI 0.709-0.789) (P = 0.693) when GLS entered the model with clinical data and LVEF.

CONCLUSION

GLS emerged as an independent long-term risk predictor of all-cause death and HF re-hospitalization. However, there was no significant incremental predictive value of GLS when LVEF was already known.

Incremental prognostic value of speckle tracking echocardiography and early follow-up echo assessment in predicting left ventricular recovery after reperfusion for ST-segment elevation myocardial infarction (STEMI)

PURPOSE

Up to 50% of patients do not achieve significant left ventricular ejection fraction (LVEF) recovery after primary percutaneous intervention (PPCI) for STEMI. We aimed to identify the echocardiographic predictors for LVEF recovery and assess the value of early follow-up echocardiography (Echo) in risk assessment of post-myocardial infarction (MI) patients.

METHODS

One hundred one STEMI patients undergoing PPCI were enrolled provided EF below 50%. Baseline echocardiography assessed LVEF, volumes, wall motion score index (WMSI), global longitudinal strain (GLS), global circumferential strain (GCS), and E/e'. Follow-up echocardiography after 6 weeks reassessed left ventricular volumes, LVEF and GLS.GCS was not assessed at follow up. Patients were classified into recovery and non-recovery groups. Predictors of LVEF recovery and major adverse cardiovascular events (MACE) at 6 months were analysed.

RESULTS

The mean change of EF was 8.04 ± 3.32% in group I versus -.39 ± 5.09 % in group II (p < .001). Recovered patients had better baseline GLS, baseline GCS, E/e', and follow-up GLS. Multivariate regression analysis revealed E/e', GCS, and follow-up GLS after 6 weeks to be strong independent predictors for LVEF recovery. Composite MACE was considerably higher in group II (32.7% vs. 4.1%, p < .001) mainly driven by higher heart failure hospitalisation Multivariate regression analysis revealed baseline GLS, E/e', and ejection fraction (EF) percentage recovery as strong independent predictors for MACE.

CONCLUSIONS

Multiparametric echocardiographic approach incorporating LVEF, strain parameters, and diastolic function could allow early optimal risk stratification after STEMI treated with PPCI. Follow-up GLS and LVEF percentage change are the strongest predictors for early LV recovery and long term clinical outcome, respectively.

Deformation Imaging by Strain in Chronic Heart Failure Over Sacubitril-Valsartan: A Multicenter Echocardiographic Registry

AIMS

Sacubitril/valsartan has changed the treatment of heart failure with reduced ejection fraction (HFrEF), due to the positive effects on morbidity and mortality, partly mediated by left ventricular (LV) reverse remodelling (LVRR). The aim of this multicenter study was to identify echocardiographic predictors of LVRR after sacubitril/valsartan administration.

METHODS AND RESULTS

Patients with HFrEF requiring therapy with sacubitril/valsartan from 13 Italian centres were included. Echocardiographic parameters including LV global longitudinal strain (GLS) and global peak atrial longitudinal strain by speckle tracking echocardiography were measured to find the predictors of LVRR [= LV end-systolic volume reduction ≥10% and ejection fraction (LVEF) improvement ≥10% at follow-up] at 6 month follow-up as the primary endpoint. Changes in symptoms [New York Heart Association (NYHA) class] and neurohormonal activations [N-terminal pro-brain natriuretic peptide (NT-proBNP)] were also evaluated as secondary endpoints; 341 patients (excluding patients with poor acoustic windows and missing data) were analysed (mean age: 65 ± 10 years; 18% female, median LVEF 30% [inter-quartile range: 25-34]). At 6 month follow-up, 82 (24%) patients showed early complete response (LVRR and LVEF ≥ 35%), 55 (16%) early incomplete response (LVRR and LVEF < 35%), and 204 (60%) no response (no LVRR and LVEF < 35%). Non-ischaemic aetiology, a lower left atrial volume index, and a higher GLS were all independent predictors of LVRR at multivariable logistic analysis (all P < 0.01). A baseline GLS < -9.3% was significantly associated with early response (area under the curve 0.75, P < 0.0001). Left atrial strain was the best predictor of positive changes in NYHA class and NT-proBNP (all P < 0.05).

CONCLUSIONS

Speckle tracking echocardiography parameters at baseline could be useful to predict LVRR and clinical response to sacubitril-valsartan and could be used as a guide for treatment in patients with HFrEF.

Echocardiography Core Laboratory Validation of a Novel Vendor-Independent Web-Based Software for the Assessment of Left Ventricular Global Longitudinal Strain

BACKGROUND

Global longitudinal strain (GLS) is an accurate and reproducible parameter of left ventricular (LV) systolic function which has shown meaningful prognostic value. Fast, user-friendly, and accurate tools are required for its widespread implementation. We aim to compare a novel web-based tool with two established algorithms for strain analysis and test its reproducibility.

METHODS

Thirty echocardiographic datasets with focused LV acquisitions were analyzed using three different semi-automated endocardial GLS algorithms by two readers. Analyses were repeated by one reader for the purpose of intra-observer variability. CAAS Qardia (Pie Medical Imaging) was compared with 2DCPA and AutoLV (TomTec).

RESULTS

Mean GLS values were -15.0 ± 3.5% from Qardia, -15.3 ± 4.0% from 2DCPA, and -15.2 ± 3.8% from AutoLV. Mean GLS between Qardia and 2DCPA were not statistically different (p = 0.359), with a bias of -0.3%, limits of agreement (LOA) of 3.7%, and an intra-class correlation coefficient (ICC) of 0.88. Mean GLS between Qardia and AutoLV were not statistically different (p = 0.637), with a bias of -0.2%, LOA of 3.4%, and an ICC of 0.89. The coefficient of variation (CV) for intra-observer variability was 4.4% for Qardia, 8.4% 2DCPA, and 7.7% AutoLV. The CV for inter-observer variability was 4.5%, 8.1%, and 8.0%, respectively.

CONCLUSIONS

In echocardiographic datasets of good image quality analyzed at an independent core laboratory using a standardized annotation method, a novel web-based tool for GLS analysis showed consistent results when compared with two algorithms of an established platform. Moreover, inter- and intra-observer reproducibility results were excellent.