Myocardial work is associated with significant left ventricular myocardial fibrosis in patients with hypertrophic cardiomyopathy

Characteristic of myocardial work in mitral valve prolapse with versus without mitral annular disjunction: A propensity-matched study

BACKGROUND

Mitral annular disjunction (MAD) tends to coexist with mitral valve prolapse (MVP) and mitral regurgitation (MR), and is also highly associated with arrhythmias. Myocardial work (MW) analysis is dedicated to estimate myocardial performance by integrating strain analysis and afterload. We aimed to use MW analysis to investigate the cardiac remodeling and dysfunction in MAD, particularly the damage of some segments, and to enhance the understanding of the correlations between MW parameters and VAs within MVP patients.

METHODS

A total of 22 consecutive MVP patients with MAD (MAD+) and 44 consecutive MVP patients without MAD (MAD-) (50 ± 11yeas; 18% females) were screened by propensity score matching (PSM), and were divided into subgroups based on MR severity (MR+: Grade 2+; MR-: ≤1), GWI median (GWI ≤ 2079.5 mmHg%; GWI>2079.5 mmHg%), as well as the presence of VAs (VAs+; VAs-). MW parameters consist of global work efficiency (GWE), global work index (GWI), global constructive work (GCW) and global wasted work (GWW).

RESULTS

The MAD+ patients had larger LVEDD and LAVI, as well as lower GWE, GWI, and GCW (all P<0.05) compared to the MAD- patients, regardless of similar GLS and regurgitant volume(both P>0.05). When categorized by MR severity, GWI (P = 0.049) and GCW (P = 0.040) were diminished in the MR-MAD+ group. The regional analysis showed MAD+ patients had decreased MW index in the basal (posterior and inferior) and mid (posterior and inferior) segments. Multivariate linear regression showed MAD phenotype, but not MR severity, was independently associated with diminished GWE, GWI, and GCW (all P<0.05). When divided by GWI median, MAD phenotype [OR (95%CI): 5.189 (1.193-22.572), P = 0.028] was an independent predictor of decreased GCW. The receiver-operating characteristic curve identified bileaflet prolapse [AUC (95%CI): 0.664 (0.502-0.825), P = 0.045], and GWI for basal inferior [(AUC (95%CI): 0.679 (0.538-0.819), P = 0.020] as the predictors of the VAs.

CONCLUSION

MAD phenotype has the ability to compromise cardiac structure and function, irrespective of volume overload, as evidenced by dilated LV and impaired MW index in basal and mid segments. Excessively decreased regional MW index can identify patients with the high risk of VAs. MW analysis can be a valuable imaging marker for detecting myocardial impairment induced by MAD.

Myocardial work by pressure-strain loop is associated with molecular imaging of fibroblast activation in hypertensive hearts using 99mTc-HFAPI SPECT

99mTc-HFAPI can visualize fibroblast activation in hypertensive hearts. Myocardial work (MW) reflects the cardiac mechanical properties after accounting for the afterload in hypertensive patients. We investigated whether MW was associated with increased uptake of 99mTc-HFAPI. A total of 97 hypertensive patients and 41 healthy volunteers were prospectively recruited. Global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were analyzed. According to whether myocardial uptake of FAPI was higher than the adjacent blood pool, hypertensive patients were divided into two groups, namely: FAPI + and FAPI- group, respectively. GWI, GCW and GWE of the FAPI + group were lower than the FAPI- group. The value of GWW in the FAPI + group was higher than in the FAPI- group. Multiple regression analyses revealed GWI, GWW and GWE were independently associated with early myocardial fibrosis. According to receiver operating characteristics (ROC) analysis, the best cutoff points for FAPI + of GWI, GWW and GWE were 1968.50 mmHg% (AUC: 0.687, 95% CI: 0.581-0.793, P = 0.002), 133.00 mmHg% (AUC: 0.778, 95% CI: 0.688-0.869, P < 0.001) and 95.07% (AUC: 0.813, 95% CI: 0.730-0.896, P < 0.001), respectively. GWI, GWW and GWE were impaired in hypertensive patients with cardiac 99mTc-HFAPI uptake and were associated with fibroblast activation in hypertensive hearts.

Myocardial Work in Apical Hypertrophic Cardiomyopathy

BACKGROUND

Pressure-strain loop analysis is a novel echocardiographic technique to calculate myocardial work indices that has not been applied to patients with apical hypertrophic cardiomyopathy (ApHCM). We hypothesized that myocardial work indices differ between patients with ApHCM and those with non-ApHCM. This study aimed to (1) evaluate myocardial work indices in patients with ApHCM compared with those with non-ApHCM, (2) describe associations with relevant clinical variables, and (3) examine associations with significant late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging.

METHODS

We retrospectively identified 48 patients with ApHCM and 69 with non-ApHCM who had measurements of global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency. We evaluated available cardiac magnetic resonance imaging data on 34 patients with ApHCM and 51 with non-ApHCM. Multivariable regression models correcting for traditional cardiac risk factors were used to evaluate the associations of myocardial work indices with relevant clinical variables.

RESULTS

Median GLS (-11% vs -18%, P < .001), GWI (966 mm Hg% vs 1803 mm Hg%, P < .001), and GCW (1,050 mm Hg% vs 1,988 mm Hg%, P < .001) were significantly impaired in patients with ApHCM compared with those with non-ApHCM. Increasing N-terminal pro b-type natriuretic peptide, abnormal ultrasensitive troponin, and increasing maximal left ventricular wall thickness were significantly associated with reduced GWI and GCW in patients with ApHCM (P < .05). Global constructive work had only modest accuracy (area under the curve [AUC] = 0.70) to predict LGE in patients with ApHCM. However, in patients with non-ApHCM, GLS was the strongest predictor of LGE (AUC = 0.91), with a -17% cutoff yielding 81% sensitivity and 80% specificity.

CONCLUSION

Myocardial work indices are significantly impaired in patients with ApHCM compared to those with non-ApHCM and correlate with important clinical variables. Global longitudinal strain, GWI, and GCW are more strongly predictive of fibrosis in patients with non-ApHCM than ApHCM.

Evaluation of global and regional myocardial work in hypertrophic cardiomyopathy patients by left ventricular pressure-strain loop

OBJECTIVE

This study aimed to investigate the value of left ventricular (LV) press-strain loop (PSL) in evaluating global and regional myocardial work (MW) in hypertrophic cardiomyopathy (HCM) patients.

METHODS

A total of 30 HCM patients with interventricular septum hypertrophy (HCM group) and 35 healthy subjects (control group) were selected from First Hospital of Qinhuangdao. The general clinical data and conventional ultrasound parameters of two groups were acquired. The MW parameters were analyzed using LV PSL. The regional MW parameters in the HCM group were compared between ventricular septum and the free walls of left ventricle.

RESULTS

The epicardial adipose tissue thickness of the HCM group was significantly greater than that of the control group (P < 0.05). Global work efficiency was significantly reduced, while global wasted work was increased in patients with HCM compared with controls (all P < 0.05). The HCM group was compared in the group, to be specific, in the HCM group, the work index, the work efficiency, and the longitudinal strain on the interventricular septum were lower than those on the free wall (all P < 0.05).

CONCLUSION

PSL is more effective than LVEF in assessing left ventricular systolic function in HCM and is able to quantify regional myocardial work in the ventricular septum in HCM patients with preserved LVEF, suggesting a novel idea for clinical diagnosis and assessment.

Predicting Left Ventricular Myocardial Fibrosis in Patients with Hypertrophic Cardiomyopathy by Speckle Tracking Automated Functional Imaging

OBJECTIVE

The study was performed to explore the predictive value of multiple strain parameters for myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) by using speckle tracking automated functional imaging (AFI).

METHODS

A total of 61 patients diagnosed with HCM were finally enrolled in this study. All patients completed transthoracic echocardiography and cardiac magnetic resonance late gadolinium enhancement (LGE) within 1 month. Twenty age- and sex-matched healthy participants were included as the control group. Multiple parameters, including segmental longitudinal strain (LS), global longitudinal strain (GLS), post-systolic index and peak strain dispersion, were automatically analyzed by AFI.

RESULTS

A total of 1458 myocardial segments were analyzed according to the left ventricular 18-segment model. Among the 1098 segments from HCM patients, segments with LGE had a lower absolute value of segmental LS than those without LGE (p < 0.05). The cutoff values of segmental LS for predicting positive LGE in the basal, intermediate and apical regions were -12.5%, -11.5% and -14.5%, respectively. GLS could predict significant myocardial fibrosis (≥2 positive LGE segments) at a cutoff value of -16.5% with a sensitivity of 80.9% and specificity of 76.5%. As an independent predictor of significant myocardial fibrosis, GLS was substantially associated with the severity of myocardial fibrosis and 5 years sudden cardiac death risk score in HCM patients.

CONCLUSION

Speckle tracking AFI could efficiently identify left ventricular myocardial fibrosis in patients with HCM by multiple parameters. GLS predicted significant myocardial fibrosis at a cutoff value of -16.5%, which may indicate the adverse clinical outcomes in HCM patients.

Association between left ventricular reverse remodeling and long-term outcomes after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

There is a paucity of data regarding the effect of left ventricular (LV) reverse remodeling (r-LVR) on diastolic function and outcomes after alcohol septal ablation (ASA) in patients with hypertrophic obstructive cardiomyopathy (HOCM). The aim of this study was to identify the impact of r-LVR on the outcome and the predictors of such changes after ASA. Eighty-seven patients (57.5% men) were enrolled and underwent both echocardiography and cardiovascular magnetic resonance (CMR) imaging at baseline and 27 months after the procedure. The study population was divided into two groups by the degree of r-LVR. Compared to the greater r-LVR group, the lesser r-LVR group had a significantly larger LV mass (LVM) and lower diastolic function parameters at baseline. The greater r-LVR group had significantly greater LVM regression and improvement of diastolic function after ASA. Kaplan‒Meier analysis showed significantly worse composite events in the lesser r-LVR group after ASA (P = 0.016). After adjusting for multiple clinical variables, r-LVR was associated with an improved E/e' (β = 0.390, p < 0.001) and reduced events (hazard ratio: 0.795; 95% confidence interval (CI), 0.644-0.983; p = 0.034). Preablation LVM was associated with a decreased probability of r-LVR (β = -0.228, p = 0.021) and diastolic function improvement (β= -0.245, p = 0.006). r-LVR was associated with long-term outcome benefit in patients with HOCM. Preablation LVM prevented LV from favoring reverse remodeling and thus may be a potential parameter for risk stratification and prognosis after ASA treatment.

Myocardial Work in Echocardiography

Myocardial work is an emerging tool in echocardiography that incorporates left ventricular afterload into global longitudinal strain analysis. Myocardial work correlates with myocardial oxygen consumption, and work efficiency can also be assessed. Myocardial work has been evaluated in a variety of clinical conditions to assess the added value of myocardial work compared to left ventricular ejection fraction and global longitudinal strain. This review showcases the current use of myocardial work in adult echocardiography and its possible role in cardiac pathologies.

Detection of myocardial fibrosis: Where we stand

Myocardial fibrosis, resulting from the disturbance of extracellular matrix homeostasis in response to different insults, is a common and important pathological remodeling process that is associated with adverse clinical outcomes, including arrhythmia, heart failure, or even sudden cardiac death. Over the past decades, multiple non-invasive detection methods have been developed. Laboratory biomarkers can aid in both detection and risk stratification by reflecting cellular and even molecular changes in fibrotic processes, yet more evidence that validates their detection accuracy is still warranted. Different non-invasive imaging techniques have been demonstrated to not only detect myocardial fibrosis but also provide information on prognosis and management. Cardiovascular magnetic resonance (CMR) is considered as the gold standard imaging technique to non-invasively identify and quantify myocardial fibrosis with its natural ability for tissue characterization. This review summarizes the current understanding of the non-invasive detection methods of myocardial fibrosis, with the focus on different techniques and clinical applications of CMR.

Myocardial work: the analytical methodology and clinical utilities

The evaluation of left ventricular (LV) systolic function is an essential part of the clinical practice of cardiology. Although left ventricular ejection fraction (LVEF) is the most validated and widely used parameter, it has fundamental limitations. LV strain is more sensitive to detect subtle myocardial dysfunction when LVEF was preserved, but it is load-dependent. Invasive left ventricular pressure-volume loop (LV-PVL) is the reliable standard to evaluate cardiac function, but its wide clinical application is limited by the risk of invasive LV pressure detection. Until the advent of non-invasive LV pressure-strain loop (LV-PSL), things have changed. LV-PSL is in good agreement with regional myocardial oxygen consumption and metabolism. Compared with traditional echocardiographic parameters or LV strain, myocardial work (MW) derived from LV-PSL is a more advanced tool that combines deformation as well as hemodynamics through integration of global longitudinal strain and non-invasive LV systolic pressure. In recent years, researches on MW are going on in full swing and show many advantages of MW. This review described the method and discussed the applications, advantages, limitations, and prospects of MW in multiple cardiovascular diseases. The goal is to provide the readers new insights for evaluating LV systolic function and promote the incorporation of MW into daily practice.

Evaluation of myocardial work in patients with hypertrophic cardiomyopathy and hypertensive left ventricular hypertrophy based on non-invasive pressure-strain loops

Background

The capacity to distinguish hypertrophic cardiomyopathy (HCM) from hypertensive left ventricular hypertrophy (H-LVH) based on morphological features obtained by conventional echocardiography is limited. We investigated the global myocardial work of the left ventricle in two types of hypertrophies using the non-invasive myocardial work index (NMWI).

Methods

Conventional echocardiography was performed on 107 subjects with preserved left ventricular ejection fraction (LVEF ≥ 50%), who comprised patients with HCM (n = 40), H-LVH (n = 35), and healthy people with normal blood pressure and left ventricular structure (n = 32). Except for the conventional echocardiographic parameters, the left ventricular myocardial work parameters based on pressure-strain loops, including global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), were evaluated in three groups. Multivariate discriminant analysis and receiver operating characteristic (ROC) curve were used to evaluate the incremental value of NMWI for distinguishing HCM from H-LVH.

Results

Compared to the control group, GWI and GCW were significantly lower in HCM patients (P < 0.05), whereas GWI was significantly higher in H-LVH patients. GWW was higher and GWE was significantly decreased in both HCM and H-LVH patients than in the control group (P < 0.05). Multivariate discriminant analysis and ROC curve revealed that the inter-ventricular septum thickness (IVST)/left ventricular posterior wall thickness (LVPWT) and GCW were each able to distinguish HCM from H-LVH. The combination of IVST/LVPWT and GCW discriminated HCM and H-LVH with a higher predictive accuracy of 94.7%.

Conclusion

NMWI may provide additional information in evaluating the myocardial function in patients with HCM and H-LVH. Myocardial work combined with conventional echocardiography could improve the clinical diagnostic accuracy of distinguishing HCM and H-LVH.

Myocardial Work Brings New Insights into Left Ventricular Remodelling in Cardio-Oncology Patients

Serial transthoracic echocardiographic (TTE) assessment of 2D left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) are the gold standard screening methods for cancer therapeutics-related cardiac dysfunction (CTRCD). Non-invasive left ventricular (LV) pressure-strain loop (PSL) provides a novel method of quantifying myocardial work (MW) with potential advantages to evaluate the impact of cardiotoxic treatments on heart function. We prospectively assessed breast cancer female patients undergoing cancer therapy through serial monitoring by 2D and 3D TTE. Patients were evaluated at T0, T1 and T2 (before, 4–6 and 12–14 months after starting therapy, respectively). Through PSL analysis, MW indices were calculated. A total of 122 patients, with a mean age of 54.7 years, who received treatment with anthracyclines (77.0%) and anti-HER2 (75.4%) were included. During a mean follow-up of 14.9 ± 9.3 months, LVEF and GLS were significantly diminished, and 29.5% developed CTRCD. All MW indices were significantly reduced at T1 compared with baseline and tended to return to baseline values at T2. Global work index and global work efficiency showed a more pronounced variation in patients with CTRCD. The presence of more than one cardiovascular risk factor, obesity and baseline left atrium volume were predictors of changes in MW parameters. In conclusion, breast cancer treatment was associated with LV systolic dysfunction as assessed by MW, with its peak at 4–6 months and a partial recovery afterwards. Assessment of myocardial deformation parameters allows a more detailed characterization of cardiac remodelling and could enhance patient screening and selection for cardioprotective therapeutics.