Application value of myocardial work technology by non-invasive echocardiography in evaluating left ventricular function in patients with chronic heart failure

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.

Predictive value of the echocardiographic noninvasive myocardial work index for left ventricular reverse remodeling in patients with multivessel coronary artery disease after percutaneous coronary intervention

BACKGROUND

Coronary artery disease (CAD) can lead to left ventricular (LV) remodeling, which, in adverse cases, has been associated with heart failure and increased mortality. Here, we aimed to evaluate the predictive value of the noninvasive myocardial work index (NIMWI) for LV reverse remodeling in patients with multivessel CAD after percutaneous coronary intervention (PCI).

METHODS

A total of 88 consecutive patients with multivessel CAD treated with PCI were identified and categorized according to the presence of LV reverse remodeling 3 months after PCI [≥15% decrease in the LV end diastolic volume (LVEDV)]. With the LV pressure-strain loop (PSL) technique, NIMWIs, including the global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), were statistically compared between the reverse LV remodeling group and nonreverse LV remodeling group 1 week before PCI.

RESULTS

Significantly lower GWI, GCW, and GWE, and significantly higher GWW were observed in the reverse LV remodeling group compared with the nonreverse LV remodeling group (P<0.05). Left ventricular mass index (LVMI), GCW, and GWE were independently associated with early LV reverse remodeling. Receiver operating characteristic (ROC) curve analysis demonstrated that GCW was the most powerful predictor of early LV reverse remodeling in patients with CAD [area under the curve (AUC) =0.867]. The optimal cutoff GCW value predictive of early LV reverse remodeling was 1,438.5 mmHg% (sensitivity, 85%; specificity, 70%).

CONCLUSIONS

GCW, among the NIMWIs, may be the major predictor of LV reverse remodeling in patients with multivessel CAD after PCI. NIMWI could potentially provide a new reference index for the quantitative evaluation of LV myocardial work.

Minor ST-T changes on electrocardiograms are associated with reduced constructive myocardial work in hypertensive patients with a preserved ejection fraction

Minor ST-T changes on electrocardiograms are observed in patients with hypertensive heart disease with a preserved left ventricular ejection fraction (LVEF); however, the relationship between minor ST-T changes and global myocardial work on echocardiograms remains unclear. We evaluated the global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) in 186 hypertensive patients with preserved LVEF (>50%) using an offline analysis system (View Pal, GE). Minor ST-T changes as well as major ST-T changes (depression in ST in lead V5 > 1 mV) were also evaluated by electrocardiography. The mean age was 79.4 ± 8.2 years (men 37.6%). Patients with minor and major ST-changes had a smaller absolute GLS (-20.3 ± 3.1, -18.2 ± 3.7, and -15.2 ± 5.0%, P < 0.001) and a smaller constructive workload [GWI (2148 ± 486, 1938 ± 462, and 1685 ± 701 mmHg%, P = 0.002) and GCW (2419 ± 510, 2185 ± 466, and 1865 ± 702 mmHg%, P < 0.001)] than those with no ST-T changes. Additionally, patients with minor and major ST-T changes had increased wasted myocardial work [GWW (87 ± 61, 105 ± 56, and 127 ± 75 mmHg%, P = 0.045)], which resulted in reductions in the myocardial work efficiency [GWE (95 ± 4, 94 ± 3, and 89 ± 12%, P < 0.001)]. Even after adjustments for confounding factors, including EF, diastolic function parameters, LV hypertrophy, history of heart failure and atrial fibrillation, patients with minor ST-T changes had significantly smaller LV global constructive work in comparison to those without [GWI (2260 ± 33 vs. 2025 ± 76 mmHg%, P = 0.007) and GCW (2501 ± 45 vs. 2210 ± 105 mmHg%, P = 0.003)]. In conclusion, in hypertensive patients with preserved LVEF, minor ST-T changes on electrocardiograms were associated with reduced constructive work in the LV.