Incremental Prognostic Use of Left Ventricular Global Longitudinal Strain in Asymptomatic/Minimally Symptomatic Patients With Severe Bioprosthetic Aortic Stenosis Undergoing Redo Aortic Valve Replacement

Role of myocardial strain and rotation for predicting prosthetic aortic valve stenosis

Pressure overload due to aortic stenosis leads to subclinical left ventricular (LV) dysfunction and global longitudinal strain (GLS) impairment even if ejection fraction is preserved. However, little is known about LV mechanics in aortic prosthetic valve (APV) stenosis. The study aimed to determine the role of myocardial strain and rotation in predicting prosthetic valve stenosis in mechanical APV patients. 60 patients with mechanical APV and 30 healthy individuals were evaluated. APV patients were analyzed in two groups; aortic valve mean gradient < 20 mmHg (27 normal gradient patients) and ≥ 20 mmHg (33 high gradient patients). Strain, rotation, and twist values were assessed using the speckle tracking method, and brain natriuretic peptide (BNP) levels were measured. Four-chamber (p < 0.001) and two-chamber (p = 0.008) longitudinal strain (LS) were higher in the control group. GLS was lower in the high gradient group than control and normal gradient groups (p < 0.001, p = 0.022). LS of lateral wall's basal and mid segments were lower in normal and high gradient groups than the control group (p = 0.003, p = 0.008). While basal rotation was lower in the high gradient group than the control group (p = 0.048), there was no difference between the groups in terms of apical rotation, and twist. BNP levels were significantly different between the groups (p = 0.048). No correlation was found between aortic valve mean gradient and GLS, basal rotation, and BNP. In conclusions, LV GLS and basal rotation are depressed in high APV gradient patients; however, these parameters are not independent predictors of gradient increment.

Circulating Circular RNAs: Novel Biomarkers for Heart Failure

Heart failure (HF) is a serious, chronic disease, causing significant ill health and high mortality worldwide. The current clinical strategies emphasize reducing the transition from a healthy to a failing heart despite the shift in the clinical goal from healing to disease prevention. Recent research advancements on noncoding RNAs (ncRNAs) have demonstrated that circular RNAs (circRNAs) are significant therapeutic targets in HF. Previous studies have highlighted the potential applicability of circRNAs in the diagnosis and treatment of diseases. However, less is known regarding the potential benefits of circRNAs as novel diagnostic and treatment biomarkers for HF. In the present study, we summarize the current developments and achievements associated with the use of circRNAs as HF biomarkers. We also discuss future research directions regarding HF diagnosis and treatment.

Left ventricular global longitudinal strain and cardiac surgical outcomes

Global longitudinal strain (GLS) has emerged as a valuable diagnostic and prognostic tool for evaluating left ventricular (LV) function. GLS has been shown to be a more sensitive marker of LV dysfunction than LV ejection fraction alone and have prognostic impact in non-surgical cardiac populations. GLS, is validated, reproducible, and easily obtained from 2-dimensional speckle-tracking echocardiography. While there is strong evidence for using GLS in clinical decision-making in non-surgical populations, there is less summarized evidence on using GLS in the cardiac surgical population. This review combines the evidence on the implications of using baseline transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) GLS in cardiac surgical populations including ischemic and structural heart disease to determine surgical outcomes. We found that results seem promising on the prognostic utility of LV strain in cardiac surgical populations. However due to the variability of study populations and outcomes, and modalities (TTE versus TEE), further research on normal versus abnormal values for different surgical populations, as well potential treatment options that may modify and potentially decrease surgical risk for those with abnormal GLS are needed.

Global longitudinal strain in prosthesis-patient mismatch: relation to left ventricular mass regression and outcomes

AIMS

Aortic prosthesis-patient mismatch (PPM) increases left ventricular (LV) afterload and prevents LV mass regression (LVMR) after surgery. This study was designed to investigate the association between the baseline global longitudinal strain (GLS) and the postoperative LVMR, and its relation to adverse outcomes.

METHODS

A total of 316 patients with aortic stenosis undergoing isolated mechanical prosthesis implantation were screened, and data from 91 patients with aortic PPM and 165 non-PPM patients were retrospectively collected. All 256 patients underwent measurement of GLS by two-dimensional speckle-tracking echocardiography preoperatively, and were followed up for postoperative changes of LV mass index (LVMi) and other clinical outcomes.

RESULTS

During the follow-up, LVMi in PPM patients decreased significantly from 139.6 ± 20.8 to 119.6 ± 26.5 g/m (P < 0.001). These patients were divided into two groups according to the median value of the reduction rate of LVMi at final follow-up, and preoperative GLS markedly decreased in PPM patients with insignificant reduction in LVMi. Multivariate analysis identified preoperative GLS (odds ratio 3.45, 95% confidence interval 1.27-11.05, P = 0.002) and preoperative LVMi (odds ratio 2.87, 95% confidence interval 1.21-8.13, P = 0.012) as independently associated with an insignificant LVMR. Moreover, PPM patients with limited reduction in LVMi were at an increased risk of cardiac death and major adverse valve-related events.

CONCLUSION

In patients with aortic PPM early after surgery, reduced preoperative GLS could be a novel sensitive risk factor for a limited regression of LV hypertrophy, and this is associated with an increased risk of adverse events in PPM patients.

Incremental Predictive Value of Longitudinal Axis Strain and Late Gadolinium Enhancement Using Standard CMR Imaging in Patients with Aortic Stenosis

To analyse the predictive ability and incremental value of left ventricular longitudinal axis strain (LAS) and late gadolinium enhancement (LGE) using standard cardiovascular magnetic resonance (CMR) imaging for the diagnosis and prognosis of severe aortic stenosis (AS) in patients with an indication for aortic valve replacement. We conducted a prospective study on 52 patients with severe AS and 52 volunteers. The evaluation protocol included standard biochemistry tests, novel biomarkers of myocardial fibrosis, 12-lead electrocardiograms and 24-hour Holter, the 6-minute walk test and extensive echocardiographic and CMR imaging studies. Outcomes were defined as the composite of major cardiovascular events (MACEs). Among AS patients, most (n = 17, 77.2%) of those who exhibited LGE at CMR imaging had MACEs during follow-up. Kaplan–Meier curves for event-free survival showed a significantly higher rate of MACEs in patients with LGE (p < 0.01) and decreased LAS (p < 0.001). In Cox regression analysis, only reduced LAS (hazard ratio 1.33, 95% CI (1.01 to 1.74), p < 0.01) and the presence of LGE (hazard ratio 11.3, 95% CI (1.82 to 70.0), p < 0.01) were independent predictors for MACEs. The predictive value increased if both LGE and reduced LAS were added to left ventricular ejection fraction (LVEF). None of the biomarkers of increased collagen turnover exhibited any predictive value for MACEs. LAS by CMR is an independent predictor of outcomes in patients with AS and provides incremental value beyond the assessment of LVEF and the presence of LGE.