Speckle-tracking echocardiography in comparison with ejection fraction for prediction of cardiovascular mortality in patients with end-stage renal disease

The incremental value of left ventricular energy loss in predicting adverse events in chronic kidney disease patients with preserved ejection fraction

BACKGROUND

Vector flow mapping (VFM) is a new echocardiographic technology that can effectively evaluate systolic and diastolic hemodynamic function. However, little is known about the prognostic value of VFM-related parameters. In this paper we aimed to investigate whether left ventricular energy loss (EL) parameters as assessed by VFM enhance prediction of adverse events in patients with chronic kidney disease with preserved ejection fraction.

METHODS

One hundred thirty-nine prospectively recruited patients (66% male, 58% on dialysis) with CKD stage 3-5 with normal left ventricular ejection fraction (LVEF) made up the study cohort. Global longitudinal strain (GLS) was calculated using 2-dimensional speckle tracking, and the LV EL during one cardiac cycle for each period was measured using VFM technology. Participants were followed for 4.17 ± 1.58 years for the primary end point of overall mortality and major adverse cardiovascular events (MACE).

RESULTS

Forty-five (32%) patients had a primary endpoint event. The EL during each period especially during the ejection stage (Ej-EL) was significantly higher in patients with adverse events than in those without, meanwhile the LV GLS were lower. The Ej-EL (HR: 1.11; 95% CI: 1.06-1.15) and LV GLS (HR: 0.87; 95% CI: 0.81-0.94) (all P < .001) were independent predictors for the primary end point. Increased Ej-EL (≥6.13, 10-3 J/m s) and impaired GLS (<15.52, %) were associated with a higher risk of overall mortality death and MACE (log rank χ2 = 26.94, 7.19; P < .001, =0.007), and DeLong tests showed that Ej-EL (AUC = 0.823) has a slight advantage in predicting adverse events compared to GLS (AUC = 0.681). Furthermore, the addition of Ej-EL to a model with conventional parameters did more to improve the model's discrimination compared to GLS.

CONCLUSIONS

Increased Ej-EL as determined by VFM is associated with a higher risk of overall death and MACE in CKD patients with preserved EF.

Chronic kidney disease is related to impaired left ventricular strain as assessed by cardiac magnetic resonance imaging in patients with ischemic cardiomyopathy

INTRODUCTION

Chronic kidney disease (CKD) is an important cardiovascular risk factor. However, the relationship between CKD and myocardial strain as a parameter of myocardial function is still incompletely understood, particularly in patients with ischemic cardiomyopathy (ICM). Cardiac magnetic resonance imaging (CMR) feature tracking allows to analyze myocardial strain with high reproducibility. Therefore, the aim of the present study was to assess the relationship between CKD and myocardial strain as described by CMR in patients with ICM.

METHODS

We retrospectively performed CMR-based myocardial strain analysis in 89 patients with ICM and different stages of CKD, classified according to the KDIGO stages. In all patients, global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) analysis of left ventricular myocardium were performed. Furthermore, segmental longitudinal (SLS), circumferential (SCS) and radial strain (SRS) according to the AHA 16/17-segment model was determined.

RESULTS

Creatinine levels (GLS: r = 0.46, p < 0.001; GCS: r = 0.34, p = 0.001; GRS: r = - 0.4, p < 0.001), urea levels (GLS: r = 0.34, p = 0.001; GCS: r = 0.30, p = 0.005; GRS: r = - 0.31, p = 0.003) as well as estimated glomerular filtration rate (GLS: r = -0.40, p < 0.001; GCS: r = - 0.27, p = 0.012; GRS r = 0.34, p < 0.001) were significantly associated with global strains as determined by CMR. To further investigate the relationship between CKD and myocardial dysfunction, segmental strain analysis was performed: SLS was progressively impaired with increasing severity of CKD (KDIGO-1: - 11.93 ± 0.34; KDIGO-5: - 7.99 ± 0.38; p < 0.001 for KDIGO-5 vs. KDIGO-1; similar data for SCS and SRS). Interestingly, myocardial strain was impaired with CKD in both segments with and without scarring. Furthermore, in a multivariable analysis, eGFR was independently associated with GLS following adjustment for LV-EF, scar burden, diabetes, hypertension, age, gender, LV mass or LV mass index.

CONCLUSION

CKD is related to impaired LV strain as assessed by CMR in patients with ICM. In our cohort, this relationship is independent of LV-EF, the extent of myocardial scarring, diabetes, hypertension, age, gender, LV mass or LV mass index.

Assessment of the Prognostic Value of MRI Left Ventricular Global Function Index (LVGFI) in Patients With End-Stage Renal Disease Under Maintenance Dialysis

BACKGROUND

Left ventricular global function index (LVGFI) integrates LV volumetric and functional parameters. In patients with end-stage renal disease (ESRD), cardiac injury manifests as LV hypertrophy and dysfunction. However, the prognostic value of LVGFI in this population remains unclear.

PURPOSE

To investigate the association of LVGFI with major adverse cardiac events (MACE) in patients with ESRD.

STUDY TYPE

Prospective.

POPULATION

One hundred fifty-eight ESRD patients (mean age: 54.1 ± 14.4 years; 105 male) on maintenance dialysis.

FILED STRENGTH/SEQUENCE

3.0 T, balanced steady-state free precession (bSSFP) cine and modified Look-Locker inversion recovery (MOLLI) sequences.

ASSESSMENT

LV volumetric and functional parameters were determined from bSSFP images. LVGFI was calculated as the ratio of stroke volume to global volume and native T1 was determined from MOLLI T1 maps. MACE was recorded on follow up. Models were developed to predict MACE from conventional risk factors combined with LVGFI, GLS, native T1, and LV mass index (LVMI), respectively. Subgroup analyses were further performed in participants with LVEF above median.

STATISTICAL TESTS

Cox proportional hazard regression and log-rank test were used to investigate the association between LVGFI and MACE. The predictive models were evaluated and compared using Harrell's C-statistics and DeLong tests. A P value <0.05 was considered statistically significant.

RESULTS

Thirty-four MACE occurred during the median follow-up period of 26 months. The hazard of MACE increased by 114% for each 10% decrease in LVGFI in univariable analysis. The predictive model consisting of LVGFI (C-statistic: 0.724) had significantly better predictive performance than the others (all P < 0.001). These results were consistent in patients (N = 79) with LVEF > median (63.54%).

DATA CONCLUSION

LVGFI is a novel marker for MACE risk stratification in patients with ESRD and was better able to predict MACE than native T1 mapping and GLS.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Left ventricular strain and myocardial work in short-term peritoneal dialysis patients

BACKGROUND

Initiation of dialysis encompasses new cardiovascular challenges on patients with end-stage renal disease (ESRD). This study used two-dimensional speckle-tracking echocardiography (2D-STE) to investigate the change of left ventricular (LV) myocardial function undergoing peritoneal dialysis (PD) within 1-3 months.

METHODS

A total of 56 patients with ESRD and 27 healthy controls were enrolled in this prospective study. Mean duration of PD was 44.41 ± 16.44 days. We evaluated LV myocardial function of patients with ESRD in baseline and within 1-3 months after PD by 2D-STE with global longitudinal strains (GLS) and myocardial work (MW). Based on the level of serum phosphate before PD, patients were divided into two groups: the group with normal serum phosphate or hyperphosphatemia.

RESULTS

Compared with healthy controls, patients with ESRD had impaired GLS (p < .001) and increased global work index (GWI) (p = .034), global constructive work (GCW) (p < .001), global wasted work (GWW) (p < .001), and lower global work efficiency (GWE) (p = .002). After PD therapy, GWI (p = .001), GCW (p < .001), and GWW (p = .023) decreased and closed to healthy subjects (p > .05) and no significant improvement was observed in GLS (p = .387). GLS of basal segments worsened in the hyperphosphatemia group (p = .005) and GWW reduced remarkably in the group with normal serum phosphate after PD treatment (p = .008). The change of left ventricular internal diameter in diastole (LVIDd) was the only parameter influenced GWI in post-dialysis patients (β = 0.324, p = .013).

CONCLUSIONS

Short-term PD treatment improved LV MW in ESRD patients. They benefited more when receiving treatment before the increase of serum phosphorus.

Influence of Physical Training after a Myocardial Infarction on Left Ventricular Contraction Mechanics

BACKGROUND

Exercise plays a positive role in the course of the ischemic heart disease, enhancing functional capacity and preventing ventricular remodeling.

OBJECTIVE

To investigate the impact of exercise on left ventricular (LV) contraction mechanics after an uncomplicated acute myocardial infarction (AMI).

METHODS

A total of 53 patients was included, 27 of whom were randomized to a supervised training program (TRAINING group), and 26 to a CONTROL group, who received usual recommendations on physical exercise after AMI. All patients underwent cardiopulmonary stress testing and a speckle tracking echocardiography to measure several parameters of LV contraction mechanics at one month and five months after AMI. A p value < 0.05 was considered statistically significant for the comparisons of the variables.

RESULTS

No significant difference were found in the analysis of LV longitudinal, radial and circumferential strain parameters between groups after the training period. After the training program, analysis of torsional mechanics demonstrated a reduction in the LV basal rotation in the TRAINING group in comparison to the CONTROL group (5.9±2.3 vs. 7.5±2.9o; p=0.03), and in the basal rotational velocity (53.6±18.4 vs.68.8±22.1 º/s; p=0.01), twist velocity (127.4±32.2 vs. 149.9±35.9 º/s; p=0.02) and torsion (2.4±0.4 vs. 2.8±0.8 º/cm; p=0.02).

CONCLUSIONS

Physical activity did not cause a significant improvement in LV longitudinal, radial and circumferential deformation parameters. However, the exercise had a significant impact on the LV torsional mechanics, consisting of a reduction in basal rotation, twist velocity, torsion and torsional velocity which can be interpreted as a ventricular "torsion reserve" in this population.

Echocardiogram screening in pediatric dialysis and transplantation

Transthoracic echocardiography is commonly used to identify structural and functional cardiac abnormalities that can be prevalent in childhood chronic kidney failure (KF). Left ventricular mass (LVM) increase is most frequently reported and may persist post-kidney transplant especially with hypertension and obesity. While systolic dysfunction is infrequently seen in childhood chronic KF, systolic strain identified by speckle tracking echocardiography has been frequently identified in dialysis and it can also persist post-transplant. Echocardiogram association with long-term outcomes has not been studied in childhood KF but there are many adult studies demonstrating associations between increased LVM, systolic dysfunction, strain, diastolic dysfunction, and cardiovascular events and mortality. There has been limited study of interventions to improve echocardiogram status. In childhood, improved blood pressure has been associated with better LVM, and conversion from hemodialysis to hemodiafiltration has been associated with better diastolic and systolic function. Whether long-term cardiac outcomes are also improved with these interventions is unclear. Echocardiography is a well-established technique, and regular use in childhood chronic KF seems justified. A case can be made to extend screening to include speckle tracking echocardiography and intradialytic studies in high-risk populations. Further longitudinal studies including these newer echocardiogram modalities, interventions, and long-term outcomes would help clarify recommendations for optimal use as a screening tool.