Clinical Applications of Echo Strain Imaging: a Current Appraisal

Global longitudinal strain and the risk of major adverse cardiac events in post-myocardial infarction patients: A retrospective cohort study

BACKGROUND

This study evaluates the relationship between global longitudinal strain (GLS) and late major adverse cardiovascular events (MACEs) in patients after acute myocardial infarction (AMI).

METHODS

Data of newly diagnosed AMI patients between March 2010 and July 2014 were retrospectively evaluated. The patients underwent serial echocardiography at admission and at third and sixth months post-admission. We calculated GLS by averaging the strain from all myocardial segments using speckle-tracking echocardiography (STE). We used multivariate Cox regression analysis and receiver operating characteristic (ROC) curve analyses to assess the relationship between GLS at admission and late MACEs.

RESULTS

Eighty-nine newly diagnosed AMI patients were enrolled. The average age at diagnosis was 61 ± 12.5 years, and approximately 89.9% of the patients were men. The average level of GLS was -17.5 ± 3.9%. The overall prevalence of MACEs was 23.6% (21/89), compared with 44 % (11/25) in the group with GLS≥-15 % and 17.9% (5/28) in the group with GLS<-20%. GLS was positively linked with MACEs in the fully adjusted Cox proportional hazard model (hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.04-1.37; P=0.014) after adjusting potential confounders. The ROC curve analysis for one year MACEs between GLS at admission, with the most significant area under the curve(AUC) 78.1% (95% CI, 63.8% - 92.6%).

CONCLUSIONS

Myocardial dysfunction, characterized by impaired GLS, is often observed in AMI patients, and a decrease in GLS levels at admission were associated with an increased risk of long-term MACEs in post-myocardial infarction patients.

Myocardial strain: a clinical review

BACKGROUND

Myocardial strain-change in myocardial fibre length over the cardiac cycle-is a measure of cardiac muscle function. It is obtained using conventional techniques such as echocardiography and magnetic resonance imaging, adding additional clinical information to augment the current techniques.

METHODS

A narrative review of the current relevant literature with respect to myocardial strain, with a focus on strain measured by echocardiography.

RESULTS

Myocardial strain identifies global and regional abnormalities in myocardial function and differentiates types of cardiomyopathy. It is an earlier marker of myocardial disease than ejection fraction and is predictive of cardiovascular adverse events. Accurate measurement requires high-quality images and experienced practitioners.

CONCLUSION

This review explains advantages and disadvantages of myocardial strain imaging and explains why, through adding increased precision without additional burden, it should be a standard part of cardiac assessment.

Cardiovascular Imaging in Cardio-Oncology: The Role of Echocardiography and Cardiac MRI in Modern Cardio-Oncology

Cardiovascular (CV) events are an increasingly common limitation of effective anticancer therapy. Over the last decade imaging has become essential to patients receiving contemporary cancer therapy. Herein we discuss the current state of CV imaging in cardio-oncology. We also provide a practical apparatus for the use of imaging in everyday cardiovascular care of oncology patients to improve outcomes for those at risk for cardiotoxicity, or with established cardiovascular disease. Finally, we consider future directions in the field given the wave of new anticancer therapies.

The Diagnostic Role of Echocardiographic Strain Analysis in Patients Presenting with Chest Pain and Elevated Troponin: A Multicenter Study

BACKGROUND

Myocarditis presenting as acute chest pain with elevated troponins without significant cardiac compromise is rare in previously healthy children, often referred to as myopericarditis. Diagnosis is challenging as conventional echocardiographic measures of systolic function can be normal. This study aimed to demonstrate the diagnostic utility of strain imaging in this scenario.

METHODS

This is a multi-center retrospective study including patients presenting with chest pain and elevated troponin from 10 institutions who underwent cardiac MRI (CMR) and transthoracic echocardiogram (echo) within 30 days of each other (group 1). Findings were compared to 19 controls (group 2). Clinical data, conventional echo and CMR data were collected. Echo-derived strain was measured at the core lab. Group 1 was divided into subgroups as CMR myocarditis positive (group 1a) or negative (group 1b) based on established criteria.

RESULTS

Group 1 included 108 subjects (88 in group 1a, 20 in group 1b). While all groups had normal mean fractional shortening (FS) and mean left ventricular ejection fraction (LVEF), group 1 had significantly lower EF (56.8+/-7.0) compared to group 2 ( 62.3+/- 4.9, P<0.005) and FS (31.2+/- 4.9) compared to group 2 (34.1+/-3.5, p<0.05). Additionally, peak global longitudinal strain (GLS%) was markedly abnormal in group 1 (-13.9+/-3.4 ) compared to group 2 (-19.8+/-2.1 , P<0.001). In subgroup analysis, GLS% was markedly abnormal in group 1a (-13.2 ± 3.0%) compared to group 1b (-17.3 ± 2.6% and p<0.001). Fifty-four subjects had follow up echocardiograms (46 in group 1a, 8 in group 1b) with mean follow-up time of 10 months (SD=11 months). At follow up, while EF and FS returned to normal in all patients, abnormalities in strain persisted in group 1, with 22% of them still having abnormal GLS. Moreover, mean GLS was more abnormal in group 1a (-16.1 +/- 2.6) compared to group 1b (-17.4+/- 1.2, p<0.05).

CONCLUSIONS

Our study demonstrates that echo GLS% is significantly worse in subjects with myopericarditis presenting with chest pain and elevated troponins compared to controls even when conventional measures of systolic function are largely normal and that these abnormalities persisted overtime.