Defining Biventricular Abnormalities by Cardiac Magnetic Resonance in Pre-Dialysis Patients with Chronic Kidney Disease

Introduction

The aim of the study was to investigate biventricular structural and functional abnormalities in pre-dialysis patients across stages of chronic kidney disease (CKD) by cardiac magnetic resonance (CMR).

Methods

Fifty-one CKD patients with CMR exams were retrospectively analyzed. Patients were divided into three groups according to estimated glomerular filtration rate (eGFR): CKD 1 group (patients with normal eGFR≥90 mL/min/1.73 m2, n = 20), CKD 2-3 group (patients with eGFR< 90 to ≥30 mL/min/1.73 m2, n = 14), and CKD 4-5 group (patients with eGFR<30 mL/min/1.73 m2, n = 17). Twenty-one age- and sex-matched healthy controls (HC) were recruited. CMR-derived left ventricular (LV) and right ventricular (RV) structural and functional measures were compared. Association between CMR parameters and clinical measures was assessed.

Results

There was an increasing trend in RV mass index (RVMi) and LV mass index (LVMi) with the occurrence and development of CKD from HC group to CKD 4-5 group although no significant difference was observed between CKD 1 group and HC group. LV global radial strain and LV global circumferential strain dropped and native T1 value elevated significantly in CKD 4-5 group compared with the other three groups (all p < 0.05), while RV strain measures, RV ejection fraction, and LV ejection fraction showed no significant difference among 4 groups (all p > 0.05). Elevated LV end-diastolic volume index (β = 0.356, p = 0.016) and RV end-systolic volume index (β = 0.488, p = 0.001) were independently associated with RVMi. Increased systolic blood pressure (β = 0.309, p = 0.004), LV end-systolic volume index (β = 0.633, p < 0.001), and uric acid (β = 0.261, p = 0.013) were independently associated with LVMi. Meanwhile, serum phosphorus (β = 0.519, p = 0.001) was independently associated with native T1 value.

Conclusion

In pre-dialysis CKD patients, left and right ventricular remolding has occurred. RVMi and LVMi were the first changed CMR indexes in the development of CKD when eGFR began to drop. Because fluid volume overload was the independent risk factor for RVMi and LVMi increase, reasonable controlling fluid volume overload may slow down the progression of biventricular remolding and may reduce related cardiovascular disease risk.

Cardiac magnetic resonance imaging parameters show association between myocardial abnormalities and severity of chronic kidney disease

BACKGROUND

Chronic kidney disease patients have increased risk of cardiovascular abnormalities. This study investigated the relationship between cardiovascular abnormalities and the severity of chronic kidney disease using cardiac magnetic resonance imaging.

METHODS

We enrolled 84 participants with various stages of chronic kidney disease (group I: stages 1-3, n = 23; group II: stages 4-5, n = 20; group III: hemodialysis patients, n = 41) and 32 healthy subjects. The demographics and biochemical parameters of the study subjects were evaluated. All subjects underwent non-contrast cardiac magnetic resonance scans. Myocardial strain, native T1, and T2 values were calculated from the scanning results. Analysis of covariance was used to compare the imaging parameters between group I-III and the controls.

RESULTS

The left ventricular ejection fraction (49 vs. 56%, p = 0.021), global radial strain (29 vs. 37, p = 0.019) and global circumferential strain (-17.4 vs. -20.6, p < 0.001) were significantly worse in group III patients compared with the controls. Furthermore, the global longitudinal strain had a significant decline in group II and III patients compared with the controls (-13.7 and -12.9 vs. -16.2, p < 0.05). Compared with the controls, the native T1 values were significantly higher in group II and III patients (1,041 ± 7 and 1,053 ± 6 vs. 1,009 ± 6, p < 0.05), and T2 values were obviously higher in group I-III patients (49.9 ± 0.6 and 53.2 ± 0.7 and 50.1 ± 0.5 vs. 46.6 ± 0.5, p < 0.001). The advanced chronic kidney disease stage showed significant positive correlation with global radial strain (r = 0.436, p < 0.001), global circumferential strain (r = 0.386, p < 0.001), native T1 (r = 0.5, p < 0.001) and T2 (r = 0.467, p < 0.001) values. In comparison with the group II patients, hemodialysis patients showed significantly lower T2 values (53.2 ± 0.7 vs. 50.1 ± 0.5, p = 0.002), but no significant difference in T1 values (1,041 ± 7 vs. 1,053 ± 6).

CONCLUSIONS

Our study showed that myocardial strain, native T1, and T2 values progressively got worse with advancing chronic kidney disease stage. The increased T1 values and decreased T2 values of hemodialysis patients might be due to increasing myocardial fibrosis but with reduction in oedema following effective fluid management.

TRIAL REGISTRATION NUMBER

ChiCTR2100053561 (http://www.chictr.org.cn/edit.aspx?pid=139737&htm=4).

Value of native T1 mapping in the prediction of major adverse cardiovascular events in hemodialysis patients

OBJECTIVES

This study aimed to evaluate the association of myocardial characterization by native T1 mapping using cardiac MR (CMR) with the incidence of major adverse cardiovascular event (MACE) in end-stage renal dysfunction (ESRD) patients on hemodialysis.

METHODS

A total of 52 ESRD patients and 52 healthy individuals were prospectively recruited between June 2017 and June 2018. ESRD patients underwent CMR examinations post-hemodialysis for the evaluation of cardiac function and global native T1 mapping. Demographics, serum biomarkers, and coronary artery calcification were collected. MACE including all-caused death, and new onset of myocardial infarction, heart failure leading to hospitalization, fatal arrhythmia, and cardiac arrest was set as the endpoint.

RESULTS

During a median follow-up of 38.0 months, 13 patients (25.0%) reached the endpoints. Global native T1 mapping in patients on hemodialysis was significantly higher compared with that of healthy individuals (1280.3 ms ± 45.3 vs. 1238.2 ms ± 31.1, p < 0.001). In the univariate Cox regression analysis, global native T1 mapping (HR [hazard ratios]: 1.887, 95% CI [confidence interval]: 1.302-2.736, p = 0.001) was associated with the prediction of MACE. Multivariate Cox regression analysis demonstrated that global native T1 mapping (HR: 1.580, 95% CI: 1.112-2.244, p = 0.011) and age (HR: 1.088, 95% CI: 1.032-1.146, p = 0.002) were associated with the incidence of MACE after adjusting for other conventional risk factors.

CONCLUSIONS

Global native T1 mapping by CMR can potentially become a novel predictor of MACE in ESRD patients on hemodialysis, providing additional prognostic values over conventional risk factors. However, this conclusion should be validated in a larger sample size of hemodialysis patients.

KEY POINTS

• Global native T1 mapping was significantly higher in ESRD patients on hemodialysis compared with that of normal controls. • Global native T1 mapping was associated with myocardial enzymes, myocardial hypertrophy, coronary calcification, and cardiac function. • Global native T1 mapping value was independently predictive of MACE in hemodialysis patients, providing additional prognostic values over conventional risk factors.

Left Ventricular Strain Analysis by Tissue Tracking- Cardiac Magnetic Resonance for early detection of Cardiac Dysfunction in children with End-Stage Renal Disease

BACKGROUND

Cardiovascular disease is a major cause of morbidity and mortality in end-stage renal disease (ESRD). Reduction in left ventricular ejection fraction (LVEF) represents late left ventricle (LV) dysfunction. Cardiac MRI myocardial strain analysis is an alternative method for assessment of LV function.

PURPOSE

To investigate whether LV strain analysis is more sensitive than LVEF for early detection of systolic dysfunction in children with ESRD.

STUDY TYPE

Case control.

POPULATION

Thirty-two children with ESRD (median 14 years, 17 females) and 10 healthy control (median 12.5 years, 7 females).

FIELD STRENGTH AND SEQUENCES

A 1.5 T /retrospective ECG-gated steady-state free precession (SSFP).

ASSESSMENT

LVEF, and indexed LV mass (LVMi) and LV end-diastolic volume (LVEDVi) were measured. Using tissue tracking analysis, LV endocardial and epicardial contours were traced in short and long axes at end diastole to calculate global longitudinal (GLS), circumferential (GCS) and radial (GRS) strains.

STATISTICAL ANALYSIS

Cardiac MRI and strain parameters were compared between patients and control, and between subgroup with preserved LVEF and control by Student t-test/Mann Whitney test. Diagnostic accuracy was assessed by Receiver operating characteristic analysis. Strain as predictor of poor outcome (mortality, pulmonary edema, and/or heart failure) within 1-year follow up was investigated by binary logistic regression.

RESULTS

Compared to control, cardiac MRI LVEF, LVEDVi, LVMi, GLS, GCS and GRS were significantly impaired in patients. Patients with preserved LVEF had significantly higher LVEDVi, LVMi and significantly impaired GCS and GRS than control. Strain parameters were significantly correlated with LVEF, LVEDVi, and LVMi. GCS and GRS demonstrated greater diagnostic accuracy than GLS (area under curve: 0.89). LVEF, LVMi, GCS, and GRS were correlated with poor outcome.

CONCLUSION

Cardiac MRI tissue tracking could identify subclinical LV dysfunction in children with ESRD and still preserved LVEF. Furthermore, LV strain parameters (GCS and GRS) were correlated with future cardiovascular events.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Effects of upright T-wave in lead aVR on left ventricular volume and function derived from ECG-gated SPECT in patients with advanced chronic kidney disease

BACKGROUND

Numerous studies have shown the association between chronic kidney disease (CKD) and adverse cardiac events. We investigated whether or not the upright T-wave in lead aVR (TaVR) could predict left ventricular (LV) volume and function derived from ECG-gated SPECT in patients with advanced CKD.

METHODS

Two hundred and sixty-one patients with advanced CKD [estimated glomerular filtration rate (eGFR) < 45 ml/min/1.73 m2] were enrolled. Upright TaVR was defined as a wave with a positive deflection of > 0 mV. Enlarged LV end-diastolic volume (LVEDV) was defined as LVEDV index of > 76 ml/m2 in men and > 57 ml/m2 in women. Reduced LV ejection fraction (LVEF) was defined as LVEF of < 40%.

RESULTS

Forty-six patients (18%) had upright TaVR, and 215 patients (82%) had negative TaVR. Summed redistribution score (SRS) [ 6 (1-12) vs. 2 (0-5), p < 0.001] and summed difference score (SDS) [4 (1-6) vs. 2 (0-4), p = 0.004] were significantly larger in patients with upright TaVR than those with negative TaVR. Patients with upright TaVR had larger LVEDV index (75 ± 33 ml/m2 vs. 50 ± 18 ml/m2, p < 0.001) and lower LVEF (43 ± 14% vs. 58 ± 11%, p < 0.001) compared to those with negative TaVR. After adjusted for other variables including SRS and SDS, upright TaVR remained a significant predictor of enlarged LVEDV (odds ratio 5.45; 95% CI 2.16-14.22; p < 0.001) and reduced LVEF (odds ratio 4.54; 95% CI 1.70-12.23; p = 0.003).

CONCLUSIONS

Our data suggested that upright TaVR could predict LV volume and function derived from ECG-gated SPECT in patients with advanced CKD.

Heart failure in chronic kidney disease: the emerging role of myocardial fibrosis

Heart failure (HF) is one of the main causes of morbidity and mortality in patients with chronic kidney disease (CKD). Decreased glomerular filtration rate is associated with diffuse deposition of fibrotic tissue in the myocardial interstitium [i.e. myocardial interstitial fibrosis (MIF)] and loss of cardiac function. MIF results from cardiac fibroblast-mediated alterations in the turnover of fibrillary collagen that lead to the excessive synthesis and deposition of collagen fibres. The accumulation of stiff fibrotic tissue alters the mechanical properties of the myocardium, thus contributing to the development of HF. Accumulating evidence suggests that several mechanisms are operative along the different stages of CKD that may converge to alter fibroblasts and collagen turnover in the heart. Therefore, focusing on MIF might enable the identification of fibrosis-related biomarkers and targets that could potentially lead to a new strategy for the prevention and treatment of HF in patients with CKD. This article summarizes current knowledge on the mechanisms and detrimental consequences of MIF in CKD and discusses the validity and usefulness of available biomarkers to recognize the clinical-pathological variability of MIF and track its clinical evolution in CKD patients. Finally, the currently available and potential future therapeutic strategies aimed at personalizing prevention and reversal of MIF in CKD patients, especially those with HF, will be also discussed.

The Role of Multi-modality Imaging in the Diagnosis of Cardiac Amyloidosis: A Focused Update

Cardiac amyloidosis (CA) is a unique disease entity involving an infiltrative process, typically resulting in a restrictive cardiomyopathy with diastolic heart failure that ultimately progresses to systolic heart failure. The two most common subtypes are light-chain and transthyretin amyloidosis. Early diagnosis of this disease entity, especially light-chain CA subtype, is crucial, as it portends a poorer prognosis. This review focuses on the clinical utility of the various imaging modalities in the diagnosis and differentiation of CA subtypes. This review also aims to highlight the key advances in each of the imaging modalities in the diagnosis and prognostication of CA.

The assessment of coronary artery disease in patients with end-stage renal disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in patients with ESRD. Coronary artery disease (CAD) is a key disease process, present in ∼50% of the haemodialysis population ≥65 years of age. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. For this reason, the most appropriate approach to the investigation of CAD is the subject of considerable discussion, with practice patterns largely varying between different centres. Traditional imaging modalities are limited in their diagnostic accuracy and prognostic value for cardiac events and survival in patients with ESRD, demonstrated by the large number of adverse cardiac outcomes among patients with negative test results. This review focuses on the current understanding of CAD screening in the ESRD population, discussing the available evidence for the use of various imaging techniques to refine risk prediction, with an emphasis on their strengths and limitations.