Echocardiographic Strain Imaging in Coronary Artery Disease

Arrhythmic mitral valve prolapse: a practical approach for asymptomatic patients

Mitral valve prolapse (MVP) is usually regarded as a benign condition though the proportion of patients with a life-threatening arrhythmic MVP form remains undefined. Recently, an experts' consensus statement on arrhythmic MVP has proposed approaches for risk stratification across the spectrum of clinical manifestation. However, sudden cardiac death may be the first presentation, making clinicians focused to early unmasking this subset of asymptomatic patients. Growing evidence on the role of cardiac imaging in the in-deep stratification pathway has emerged in the last decade. Pathology findings have suggested the fibrosis of papillary muscles and inferobasal left ventricular wall as the malignant hallmark. Cardiac magnetic resonance, while of limited availability, allows the identification of this arrhythmogenic substrate. Therefore, speckle-tracking echocardiography may be a gateway to prompt referring patients to further advanced imaging investigation. Our review aims to summarize the phenotypic features linked to the arrhythmic risk and to propose an image-based algorithm intended to help stratifying asymptomatic MVP patients.

Assessment of left ventricular global longitudinal strain in patients with hypertrophic cardiomyopathy and coronary artery disease

Impaired left ventricular global longitudinal strain (GLS) and coronary artery disease (CAD) each confer adverse prognosis in hypertrophic cardiomyopathy (HCM). Despite their prevalence, data on GLS in co-existent HCM and CAD is lacking. Ninety-six patients with HCM and CAD were retrospectively identified between 2005 and 2021, and analyzed using 2D speckle-tracking echocardiography. Obstructive and non-obstructive CAD patients were compared, multivariate linear regression tested associations between clinical and echocardiographic variables with GLS, and Receiver Operating Characteristic Curve assessed the utility of GLS to predict all-cause mortality at follow-up. Mean age was 71 ± 12.2 years, 41% had obstructive HCM, 78% had obstructive CAD, and 75% had prior acute coronary syndrome. At 4.8-year follow-up, GLS decreased compared with baseline (- 12.5 ± 4.5 vs. - 14 ± 4.2%, p = 0.007), with basal segments experiencing the greatest impairment. GLS was lower in obstructive versus non-obstructive CAD patients at follow-up, although the magnitude was attenuated (baseline: - 13.2 vs. - 17.1%, p < 0.001; follow-up: - 12 vs. - 14.1%, p = 0.05). Interventricular septal thickness (β = 0.54), apical HCM (β = 0.48), and right ventricular systolic pressure (β = 0.39) were associated with more impaired GLS (all p < 0.001), independent of obstructive CAD (β = 0.09, p = 0.44). There were 9 follow-up deaths, with baseline GLS > - 13.5% being a good predictor of all-cause mortality (AUC 0.78, 95% CI 0.64-0.92, sensitivity 88%, specificity 57%, p = 0.01). Patients with HCM and CAD experience progressive GLS impairment over long-term follow-up, with GLS > - 13.5% appearing to be a threshold for predicting all-cause mortality. Apical HCM phenotype is independently associated with worse GLS.

Differences in left ventricular myocardial function and infarct size in female patients with ST elevation myocardial infarction and spontaneous coronary artery dissection

Introduction

Differences in pathophysiology, clinical presentation, and natural course of ST-elevation myocardial infarction in female patients due to either spontaneous dissection (SCAD-STEMI) or atherothrombotic occlusion (type 1 STEMI) have been discussed. Current knowledge on differences in left ventricular myocardial function and infarct size is limited. The aim of this study was to assess baseline clinical characteristics, imaging findings, and therapeutic approach and to compare differences in echocardiographic findings at baseline and 3-month follow-up in patients with SCAD-STEMI and type 1 STEMI.

Methods

This was a prospective multicenter study of 32 female patients (18-55 years of age) presenting with either SCAD-STEMI due to left anterior descending coronary artery (LAD) dissection or type 1 STEMI due to atherothrombotic LAD occlusion.

Results

The two groups were similar in age, risk factors, comorbidities, and complications. SCAD-STEMI patients more often had Thrombolysis in Myocardial Infarction 3 flow, while type 1 STEMI patients were more often treated with percutaneous coronary intervention and dual antiplatelet therapy. Baseline mean left ventricular (LV) ejection fraction (LVEF) was similar in the two groups (48.0% vs. 48.6%, p = 0.881), but there was a significant difference at the 3-month follow-up, driven by an improvement in LVEF in SCAD-STEMI compared to type 1 STEMI patients (Δ LVEF 10.1 ± 5.3% vs. 1.8 ± 5.1%, p = 0.002). LV global longitudinal strain was slightly improved in both groups at follow-up; however, the improvement was not significantly different between groups (-4.6 ± 2.9% vs. -2.0 ± 2.8%, p = 0.055).

Conclusions

The results suggest that female patients with SCAD-STEMI are more likely to experience improvement in LV systolic function than type 1 STEMI patients.

Right Ventricular Function Indices at Rest and During Exercise in Hyperthyroid Patients: A Cross-sectional Study

Background

Since hyperthyroidism could be associated with right ventricular dysfunction, this study intended to investigate right ventricular (RV) function using strain echocardiography in hyperthyroid patients both at rest and in maximum-stress conditions.

Methods

This cross-sectional study was conducted at Rajaie Cardiovascular Medical and Research Center, Tehran, Iran, from January 2019 to January 2020. All study participants completed a maximum treadmill exercise test, as well as a complete two-dimensional echocardiogram at rest and the peak of stress test. The data were analyzed using SPSS statistical software. The independent samples t test and Mann-Whitney U test were used for numerical, and the Chi square test was used for nominal variables. P<0.05 was considered statistically significant.

Results

The final analysis included 52 participants (26 subjects in each group). In a maximal stress situation, we found that among the RV function indices, RV global longitudinal strain (P=0.0001), systolic strain rate (P=0.0001), diastolic strain rate (P=0.0002), and tricuspid annular plane systolic excursion (P=0.019) were reduced significantly in the hyperthyroid patients compared to the control group. There was also a linear correlation between RV size and thyroid stimulating hormone (TSH) level (P=0.009, r=0.36). Moreover, we found a negative linear correlation between TSH level with maximum stress RV strain and diastolic strain rate (P<0.001).

Conclusion

The findings of the present study revealed a significant change in RV function indices among hyperthyroid patients. Therefore, it highlights the necessity of early diagnosis and treatment of hyperthyroidism, as well as RV function evaluation in these patients.

Left atrial strain predicts risk and prognosis in patients with acute coronary syndrome: A retrospective study with external validation

Objectives

To explore the association between left atrial (LA) strain and the GRACE score in patients with acute coronary syndrome (ACS) and to investigate the utility of LA function in predicting short-term adverse cardiovascular events post ACS.

Methods

This retrospective study included ACS patients who underwent coronary angiography (CAG) in two independent cohorts from October 2020 to July 2022. The patients were classified into low-intermediate risk group and high-risk group based on the GRACE score. All participants underwent a transthoracic echocardiogram, with LA strain analysis before CAG. Correlation analysis was used to determine the relationship between LA strain and the GRACE score. The predictive value of LA strain was examined utilizing the area under the curve (AUC). Participants were followed for 10.5 ± 2.9 months for the primary endpoint of major adverse cardiovascular events (MACE).

Results

A total of 229 patients were included in this study, including 196 in the primary group and 33 in the validation group. Spearman's correlation analysis showed there was a moderate negative correlation between the GRACE and left atrial reservoir strain (LASr) in both the primary (r = -0.63, P < 0.001) and validation (r = -0.73, P < 0.001) cohorts. Receiver operator characteristic (ROC) curve analysis showed that the AUC of LASr for prediction of the high-risk group was 0.86. Taking LASr 19.6% as the cut-off value, the sensitivity and specificity were 0.71 and 0.92, respectively. The cut-off value of 19.6% remains good at identifying high-risk group in the validation group (AUC = 0.87, sensitivity: 77.8%, specificity: 95.8%). Furthermore, 49 patients reached the endpoint in the primary cohort during the follow-up. On multivariable regression analysis, LASr (P = 0.03) was the independent echocardiographic predictor for the primary endpoint, rather than left atrial volume index (LAVI).

Conclusions

LASr can identify high-risk patients with ACS as defined by the GRACE score and may be superior to Max LAVI in predicting incidents of MACE in the short-term following ACS.

Pre-excitation syndrome presenting with acute myocardial infarction

A male in his mid 50s, chronic smoker and hypertensive for 10 years presented with history suggestive of typical angina, electrocardiographic evidence of pre-excitation and serial elevation of cardiac biomarkers. Serial electrocardiograms showed subtle changes (axis shift, horizontal ST-segment changes) that could be presumptive of an anterior wall myocardial infarction. Speckle tracking echocardiography revealed territorial reduction of longitudinal strain corresponding to the left anterior descending artery with coronary angiography corroborating the same and underwent successful revascularisation. Exercise stress testing showed abrupt and complete disappearance of delta wave and normalisation of PR interval which indicates that the patient has low risk of developing malignant arrhythmias and sudden cardiac death.

Left Ventricular Twist Mechanics Before and After Aortic Valve Replacement: A Feasibility Study and Exploratory Analysis

Introduction. We examined whether intraoperative assessment of left ventricular (LV) twist mechanics is feasible with transesophageal echocardiography (TEE). We then explored whether twist mechanics were altered by hemodynamic conditions or patient comorbidities. Methods. In this sub-analysis of clinical trial data, transgastric short-axis echocardiographic images of the LV base and apex were collected in patients having aortic valve replacement (AVR) at baseline and end of surgery. Transvalvular gradients and LV systolic and diastolic function were assessed using two-dimensional (2D) and Doppler echocardiography. 2D speckle-tracking echocardiography was used for off-line analysis of LV twist, twisting rate, and untwisting rate. We examined the intraoperative change in twist mechanics before and after AVR. LV twist mechanics were also explored by diabetic status, need for coronary artery bypass grafting (CABG), and use of epinephrine/norepinephrine. Results. Of 40 patients, 16 patients had acceptable TEE images for off-line LV twist analysis. Baseline median [Q1, Q3] LV twist was 12 [7, 16]°, twisting rate was 72 [41, 97]°/sec, and untwisting rate was -91 [-154, -56]°/s. Median [Q1, Q3] change in LV twist at end of surgery was -2 [-5, 3]°, twisting rate was 7 [-33, 31]°/s, and untwisting rate was 0 [-11, 43]°/s. No difference was noted between diabetic and non-diabetic patients or AVR and AVR-CABG patients. Conclusion. LV twist was augmented in patients with aortic stenosis, though twist indices were not affected by reduced afterload, diabetes, or coronary artery disease. Intraoperative assessment of twist mechanics may provide unique information on LV systolic and diastolic function, though fewer than 50% of TEE examinations successfully assessed twist. Clinical Trial Registry. This work is a sub-analysis of a clinical trial, registered on ClinicalTrials.gov on August 19, 2010 (NCT01187329), Andra Duncan, Principal Investigator.

Quantified mitral regurgitation and left atrial function in heart failure with reduced ejection fraction: interplay and outcome implications

AIMS

The clinical and prognostic importance of functional mitral regurgitation (FMR) in heart failure patients with reduced ejection fraction (HFrEF) has been highly debated. This study aims to define FMR linkage to cardiovascular (CV) outcomes and the interplay with left atrial (LA) function in a prospective cohort of consecutive HFrEF outpatients.

METHODS AND RESULTS

Overall, 286 consecutive outpatients with chronic HFrEF were prospectively enrolled. FMR was quantified by effective regurgitant orifice area (EROA). Global peak atrial longitudinal strain (PALS) was measured by speckle tracking echocardiography. The primary endpoint was a composite of congestive heart failure hospitalization or CV death. During a mean follow-up of 4.1 ± 1.5 years, the primary endpoint occurred in 99 patients (35%). The spline modelling of the risk by FMR severity showed an excess event risk starting at about the EROA value of 0.1 cm2 . There was a remarkable graded association between the EROA strata, even if tested per 0.1 cm2 increase, and the risk of CV events (hazard ratio [HR] EROA per 0.10 cm2 increase: 1.42, 95% confidence interval [CI] 1.19-1.68; p < 0.0001). EROA ≥0.30 cm2 was associated with CV events regardless of LA function (HR 2.34, 95% CI 1.29-4.19; p = 0.005). Less severe FMR (EROA ≥0.10 cm2 ) was associated with a dismal outcome only in patients with reduced LA function (PALS <14%) (5-year CV event rate 51 ± 4%); conversely, the risk of events was relative reduced when preserved global PALS and FMR coexisted (5-year CV event rate 38 ± 6%).

CONCLUSIONS

Our results refine the independent association between FMR and CV outcome among HFrEF outpatients. Within a moderate EROA range, LA function mitigates the clinical consequences of mitral regurgitation, providing measurable proof of the interplay between regurgitation and LA compliance.

Post-systolic shortening is superior to global longitudinal strain in predicting adverse events in patients with stable coronary artery disease and preserved systolic function

Background

Post-systolic shortening (PSS) is an important indicator for early identifying myocardial dysfunction. We aimed to investigate the predictive value of PSS assessed with speckle tracking automated functional imaging (AFI) on adverse events in patients with stable coronary artery disease (CAD) and preserved systolic function.

Methods

A total of 204 consecutive patients clinically diagnosed with stable CAD and left ventricular ejection fraction (LVEF) > 50% were included. Multiple parameters were analyzed with AFI technique. The composite endpoint included all-cause mortality, heart failure, myocardial infarction and stroke.

Results

During a median follow-up of 24 months (IQR 19–28 months), 30 patients (14.7%) reached the endpoint. Patients experiencing the endpoint had a lower absolute global longitudinal strain (GLS), a higher post-systolic index (PSI), and more left ventricle walls displaying PSS than patients without events. PSI (hazard ratio, 1.15; 95% CI, 1.04–1.27; p = 0.005) and per 1 increase in the number of left ventricle walls with PSS (hazard ratio 1.52, 95% CI 1.21–1.91, p < 0.000) were independent predictors of the endpoint, whereas GLS was not significantly associated with the endpoint after adjustment models. For patients with absolute value of GLS > 15.4%, a significant prognostic superiority was found in PSI compared with GLS (AUC = 0.73 [PSI] vs. 0.58 [GLS], p = 0.024).

Conclusions

PSS is an independent predictor for adverse events in stable CAD patients with preserved systolic function, and the prognostic value may be superior to GLS in patients with normal or mildly reduced GLS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01174-y.

Multimodality Imaging in Ischemic Chronic Cardiomyopathy

Ischemic chronic cardiomyopathy (ICC) is still one of the most common cardiac diseases leading to the development of myocardial ischemia, infarction, or heart failure. The application of several imaging modalities can provide information regarding coronary anatomy, coronary artery disease, myocardial ischemia and tissue characterization. In particular, coronary computed tomography angiography (CCTA) can provide information regarding coronary plaque stenosis, its composition, and the possible evaluation of myocardial ischemia using fractional flow reserve CT or CT perfusion. Cardiac magnetic resonance (CMR) can be used to evaluate cardiac function as well as the presence of ischemia. In addition, CMR can be used to characterize the myocardial tissue of hibernated or infarcted myocardium. Echocardiography is the most widely used technique to achieve information regarding function and myocardial wall motion abnormalities during myocardial ischemia. Nuclear medicine can be used to evaluate perfusion in both qualitative and quantitative assessment. In this review we aim to provide an overview regarding the different noninvasive imaging techniques for the evaluation of ICC, providing information ranging from the anatomical assessment of coronary artery arteries to the assessment of ischemic myocardium and myocardial infarction. In particular this review is going to show the different noninvasive approaches based on the specific clinical history of patients with ICC.

Multimodality imaging of the ischemic right ventricle: an overview and proposal of a diagnostic algorithm

Right ventricular (RV) involvement is frequently detected in patients presenting with acute left ventricular myocardial infarction. The ischemic right ventricle carries a dismal outcome by predisposing the heart to arrhythmic events and mechanical or hemodynamic complications. A comprehensive RV evaluation by multimodality imaging could guide clinical practice but has always been a conundrum for the imagers. Two-dimensional echocardiography is the best first-line tool due to its availability of bedside capabilities. More advanced imaging techniques provide a more comprehensive evaluation of the complex RV geometry but are mostly reserved for the post-acute setting. Three-dimensional echocardiography has improved the evaluation of RV volumes and function. The recent application of speckle-tracking echocardiography to the right ventricle appears promising, allowing the earlier detection of subtle RV dysfunction. Cardiac magnetic resonance imaging is considered the gold standard for the RV assessment. Cardiac multidetector computed tomography could be a reliable alternative. The aim of this review is to focus on the growing importance of multimodality imaging of the ischemic right ventricle and to propose a diagnostic algorithm, in order to reach a comprehensive assessment of this too frequently neglected chamber.