Effect of Preload Reduction by Hemodialysis on Conventional and Novel Echocardiographic Parameters of Left Ventricular Structure and Function

Visualizing diastolic failure: Non-invasive imaging-biomarkers in patients with heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction is an increasing challenge for modern day medicine and has been drawing more attention recently. Invasive right heart catheterization represents the mainstay for the diagnosis of diastolic dysfunction, however due to its attributable risk of an invasive procedure, other non-invasive clinical pathways are trying to approach this pathology in clinical practice. Diastolic failure is complex, and imaging is based on various parameters. In addition to transthoracic echocardiography, numerous novel imaging approaches, such as cardiac magnetic resonance imaging, computed tomography, positron emission (computed) tomography or single photon emission tomography techniques are being used to supplement deeper insights into causal pathology and might open targets for dedicated therapy options. This article provides insights into these sophisticated imaging techniques, their incremental value for the diagnosis of this poorly understood disease and recent promising results for an enhanced prognostication of outcome and therapy monitoring.

New perspective on fatigue in hemodialysis patients with preserved ejection fraction: diastolic dysfunction : Fatigue and diastolic dysfunction

The relationship between diastolic dysfunction and fatigue in hemodialysis patients with preserved ejection fraction is unknown. In this context, the objective of this study is to assess fatigue using the relevant scales and to demonstrate its relationship with diastolic dysfunction. The patients who underwent hemodialysis were evaluated prospectively. Patients' fatigue was assessed using the Visual Analogue Scale to Evaluate Fatigue Severity (VAS-F). The echocardiographic works were performed as recommended in the American Society of Echocardiography guidelines. A total of 94 patients [mean age 64.7 ± 13.5 years, 54 males (57.4%)] were included in the study. The median VAS-F score of these patients was 68.5 (33.25-91.25), and they were divided into two groups according to this value. Peak myocardial velocities during early diastole (e') and tricuspid annular plane systolic excursion (TAPSE) values were found to be significantly lower in the group with high VAS-F scores, whereas the early diastolic flow velocities (E)/e' ratio and pulmonary artery peak systolic pressures (PAP) were found to be significantly higher (p < 0.05, for all). E/e' ratio (r 0.311, p 0.002) and PAP (r 0.281, p 0.006) values were found to be positively correlated with the VAS-F score, as opposed to the TAPSE (r - 0.257, p 0.012) and e' (r - 0.303, p 0.003) values, which were found to be negatively correlated with the VAS-F score. High fatigue scores in hemodialysis patients may be associated with diastolic dysfunction. In addition, in our study, we determined the correlation of VAS-F score with E/e' ratio, PAP and TAPSE.

Reduction of arteriovenous access blood flow leads to biventricular unloading in haemodialysis patients

AIMS

Patients on chronic haemodialysis have a wide range of changes in cardiac function and structure, including left ventricular hypertrophy, dilation and diastolic dysfunction or pulmonary hypertension. All these changes were linked to increased mortality in previous studies. High-flow arteriovenous fistulas (AVF) are supposed to be a factor contributing to their development. This study investigated the early effect of surgical AVF blood flow (Qa) reduction on these changes in patients with or without heart failure changes.

METHODS AND RESULTS

Forty-two patients in chronic haemodialysis programme with high-flow AVF (Qa over 1500 mL/min), indicated for surgery for ≥1 of the following indications: 1.manifest heart failure; 2.hand ischemia; 3.advanced structural heart changes detected by echocardiography. The patients underwent echocardiography on selection visit, before blood flow reducing surgery and six weeks thereafter. The Qa reduction led to decrease of left ventricular mass (p = 0.02), end-diastolic volume (p = 0.008), end-diastolic diameter (p = 0.003) and left atrial volume (p = 0.0006). Diastolic function improved. Similarly, right ventricular diameter and right atrial volume decreased (p = 0.000001 and 0.00009, respectively) together with the decrease of estimated pulmonary artery systolic pressure. 81% of patients suffered from pulmonary hypertension prior to surgery, only 36% thereafter.

CONCLUSION

The surgical restriction of the hyperkinetic circulation leads to several improvements of heart structure and function, which was linked to higher mortality in other studies. The beneficial effect of Qa reduction is present even in patients without symptoms of heart failure. The contribution of AVF must be considered with structural or functional heart changes.

Prevalence and factors associated with pulmonary arterial hypertension on maintenance hemodialysis patients in Kinshasa, Democratic Republic of Congo: a cross-sectional study

Background

Although cardiovascular diseases in particular Pulmonary Arterial Hypertension (PAH) is associated with, high morbid-mortality in chronic hemodialysis, but its magnitude remains paradoxically unknown in sub-Saharan Africa. The aim of this study was to evaluate the prevalence of PAH and associated factors in chronic hemodialysis in Sub-Saharan African population.

Method

In a cross-sectional study, patients treated with HD for at least 6 months in 4 hemodialysis centers were examined. PAH was defined as estimated systolic pulmonary arterial pressure (sPAP) ≥ 35 mmHg using transthoracic Doppler echocardiography performed 24 h after the HD session.

Results

Eighty-five HD patients were included; their average age was 52.6 ± 15.9 years. Fifty-seven patients (67.1%) were male. Mean duration of HD was 13.3 ± 11 months. With reference to vascular access, 12 (14.1%), 29 (34.1%) and 44 (51.8%) patients had AVF, tunneled cuff and temporary catheter, respectively. The underlying cause of ESRD was diabetes in 30 patients (35.3%). The prevalence of PAH was 29.4%. Patients with PAH had more hyponatremia (11 (44%) vs 10 (16.7%), p = 0.010). In multivariate analysis, unsecured healthcare funding (aOR 4, 95% CI [1.18–6.018]), arrhythmia (aOR 3, 95% CI [1.29–7.34]), vascular access change (aOR 4, 95% CI [1.18–7.51]) and diastolic dysfunction (aOR 5, 95% CI [1.35–9.57] were independently associated with PAH.

Conclusion

One third of hemodialysis patients exhibit PAH, which is independently associated with low socioeconomic status (unsecured funding, vascular access change) and cardiovascular complications (arrhythmia, diastolic dysfunction).

Left Ventricular Mass Assessment by 1- and 2-Dimensional Echocardiographic Methods in Hemodialysis Patients: Changes in Left Ventricular Volume Using Echocardiography Before and After a Hemodialysis Session

Rationale & Objective

Left ventricular (LV) mass (LVM) is a predictor of cardiovascular morbidity and mortality and commonly calculated using 1-dimensional (1D) echocardiographic methods. These methods are vulnerable to small measurement errors and LVM may wrongly change according to changes in LV volume (LVV). Less commonly used 2-dimensional (2D) methods can accommodate to the changes in LVV and may be a better alternative among patients receiving hemodialysis (HD) with large fluid fluctuations.

Study Design

Observational study.

Setting & Participants

Patients with end-stage kidney disease receiving HD.

Exposure

One HD session.

Analytical Approach

Transthoracic echocardiography was performed right before and after HD. LVM was calculated using 1D (Devereux, Penn, and Teichholz) and 2D methods (truncated ellipsoid and area-length).

Outcomes

Significant differences in LVM after HD.

Results

We compared dimensions, LVV and LVM, in 53 patients (mean age, 63 ± 15 years; 66% men). For each 1-L increase in ultrafiltration volume (UFV), LV internal diameter decreased 1.1 mm (95% CI, 0.5-1.7 mm; P = 0.001). Patients were divided into 2 groups by the median UFV of 1.6 L. Patients with UFV > 1.6 L had significant smaller LVV and LV internal diameter after HD. LVM calculated using 1D methods decreased according to changes in LVV. Conversely, LVM calculated using 2D methods was not significantly different after HD. No significant change in differences between diastolic - systolic myocardial thickness or LVM as assessed using 1D and 2D methods was observed before and after HD, indicating that LVM remained constant despite HD.

Limitations

We did not use contrast enhancement, 3-dimensional methods, or cardiac magnetic resonance.

Conclusions

LVM calculated using 2D methods, truncated ellipsoid and area-length, is less affected by fluctuations in fluid and LVV, in contrast to 1D methods. Complementary LVM calculation using 2D methods is encouraged, especially in patients with large fluid fluctuations in which increased LVM using a 1D method has been detected.

The occurrence of atrial fibrillation in dialysis patients and its association with left atrium volume before and after dialysis

PURPOSE

Atrial fibrillation is a serious problem, especially in patients on dialysis. The prevalence of AF in this group of patients is higher than in general population and associated with increased mortality. The aim of this study was to assess the risk of the occurrence of atrial fibrillation related to intradialysis hypotension and left atrium volume enlargement associated with dialysis. The influence of dialysis session on: E/E', V LA, E/A, E', V RA and the width of inferior vena cava of RV was analyzed.

METHODS

This study included 40 patients on hemodialysis. Echocardiographic examination was performed to assess heart condition and function, the presence of LVH and systolic and diastolic function disturbances, LV mass, LA size, LAV, RAV, E/A, E', E/E, ejection fraction in all patients before and after dialysis. Moreover, all patients had ECG Holter continuously recording heart's rhythm before and after dialysis to assess the occurrence of atrial fibrillation related to dialysis session.

RESULTS

The analysis of differences in echocardiographic parameters before and after dialysis demonstrated significantly greater left atrium volume, right atrium volume, width of inferior vena cava and e' parameter before dialysis in comparison with post-dialysis state. Significantly higher incidence of AF after dialysis was seen. Volume of left atrium exceeding 32 mm (cutoff value) was observed significantly more often in patients before dialysis. No association was observed between left ventricle mass and left atrium volume.

CONCLUSIONS

The dialysis procedure may be a trigger for atrial fibrillation and thus AF preventive measures should be introduced in dialysis patients.

Predictive value of echocardiography and its relation to Kt/V and anthropometric parameters in hemodialysis patients

BACKGROUND

In order to evaluate the predictive value of echocardiograph parameters for mortality of hemodialysis patients and their relation to Kt/V and anthropometry, a prospective, single center study was analyzed post-hoc.

METHODS

This analysis encompassed 106 patients on maintenance hemodialysis monitored for 108 months from 1996 to 2004. spKt/V was calculated using the Daugirdas formula. Anthropometric measurements included mid-arm muscle measurements (MAMC) and percentage of body fat (%fat). Echocardiography included the estimations of left ventricular wall thickness, dimensions and volumes (EDV, ESV), systolic LV function (ejection fraction - EFLV, fractional shortening - VCF, stroke volume - SV) and diastolic LV function (E/A, VTI-A wave of transmitral flow velocity), left atrial diameter, as well as assessment of clinical and biochemical parameters. The Cox proportional hazard model was used to estimate predictive values of echocardiograph parameters.

RESULTS

Kt/V correlated significantly with left ventricular systolic and diastolic volumes and function, septal and posterior wall thickness and left atrium dimension. MAMC and %fat also correlated with many echocardiograph parameters. Multivariate Cox regression selected age [HR 1.07; CI (1.03-1.12); p < 0.01], albumin [HR 0.88; CI (0.79-0.97); p < 0.05] and left atrium dimension - binary [values > 4 cm were marked as "1" and others "0" - HR 3.76; CI (1.56-9.03); p < 0.01] as independent predictors of death.

CONCLUSION

Left atrium dimension was the most important predictor of mortality among the echocardiograph parameters. Many of these parameters were related to Kt/V and anthropometric measurements and could be the combined consequence of hypervolemia and hypertension.

The effect of hemodialysis on cardiac enzyme levels and echocardiographic parameters

BACKGROUND

Cardiac troponins are specific and sensitive markers of myocardial damage. Troponin levels may increase without an obvious active cardiac disease in hemodialysis patients. In this study, we aimed to investigate the effect of a single hemodialysis session on echocardiographic parameters and cardiac enzyme levels, including cTn-I, creatine phosphokinase (CPK), and creatine kinase-MB (CK-MB).

PATIENTS AND METHODS

Forty patients under chronic hemodialysis treatment enrolled in this prospective study. All the patients had a physical examination and underwent echocardiography before and after hemodialysis. cTn-I, CPK and CK-MB levels were also determined before and after hemodialysis in all patients.

RESULTS

Post-dialysis cTn-I levels were significantly higher compared to pre-dialysis levels (p = 0.03). cTn-I levels increased in 26 patients, did not change in 1 patient and decreased in 13 patients after hemodialysis when compared to the values determined before hemodialysis. There was no significant increase in CPK and CK-MB levels after dialysis. Statistically significant changes were detected in the end-systolic diameter of the left ventricle, end-diastolic diameter of left ventricle, ejection fraction, diameter of the left atrium, diameter of the right atrium, pulmonary artery pressure and end-diastolic diameter of the right ventricle. However, there was no significant relation between these echocardiographic changes and ultrafiltration volume, blood flow rate, age, and gender.

CONCLUSIONS

Hemodialysis leads to an increase in cTnI levels. However, the effect of increased cTnI levels on survival rates in hemodialysis patients with underlying coronary artery disease has not yet been determined. Prospective multi-center studies with large sample size are required to clarify this issue.

Non invasive evaluation of cardiac hemodynamics in end stage renal disease (ESRD)

OBJECTIVE

Volume overload is typical of haemodialysis patients; correct volume status evaluation is crucial in achieving blood pressure homeostasis, hypertension management and good treatment planning. This study evaluates the effect of acute volume depletion on ultrasonographic parameters and suggests two of them as able to predict patients volume overload.

PATIENTS AND INTERVENTION

27 patients with end stage renal disease treated with haemodialysis underwent a complete echocardiographic exam before, after 90 min and at the end of the dialysis.

MAIN OUTCOME AND RESULTS

Blood pressure levels significantly drop during the first 90 min of dialysis (139 ± 20 vs 126 ± 18; p < 0.0001), reaching a steady state with significantly lower values compared to baseline (130 ± 28; p = 0.02). LV and left atrial volume significantly decreased (baseline vs end dialysis 98 ± 32 vs 82 ± 31 p = 0.003 and 28 ± 10 vs. 21 ± 9 cc/m(2) p < 0.001). A significant reduction of systolic function (EF 61.6 % ± 9 vs 58.7 % ± 9 p = 0.04), of diastolic flow velocities (E/A 1.13 ± 0.37 vs. 0.87 ± 0.38 p < 0.001) and mitral annulus TDI tissue velocity (i.e. E' lat 10.6 ± 3 vs. 9.4 ± 3 cm/s; p 0.0001) were observed. Stroke work (SW) and LV end-diastolic diameter (LVEDd) indexed to height 2.7(LVEDdi) were able to predict volume overload: cut off values of respectively 13.5 mm/m(2.7) for LVEDdi and 173 cJ for SW were able to predict with a specificity of 100 % the presence of a volemic overload of at least 4 %.

CONCLUSIONS

Blood pressure, cardiac morphology and function are significantly modified by acute volume depletion and such variations are strictly interrelated. SW and LVEDd/height(2.7) may identify ESRD patients carrying an higher volume load.

Preload dependence of gated cardiac SPECT-derived ventricular volumes in hemodialysis patients

BACKGROUND

In hemodialysis (HD) patients, the intravascular volume expansion of the pre-HD state leads to a high preload. We aim to examine its effect on myocardial perfusion gated SPECT (MPGS)-derived left ventricular (LV) volumes.

METHODS

The study comprised 50 end-stage renal disease (ESRD) patients on HD with normal 2-day stress/rest MPGS performed for kidney transplantation risk assessment. Patients (pts) comprised 23 men/27 women, with mean age of 59.4 ± 7.1 years. The time elapsed from the last HD session in hours was calculated on both days, and patients were classified according to whether it was higher (group A: 19 pts), lower (group B: 27 pts), or equal (group C: 4 pts) on the stress vs the rest day. End-diastolic, end-systolic volumes (EDV, ESV), and left ventricular ejection fraction (LVEF) were determined using QGS™ software. Transient ischemic dilation (TID) ratios were derived from the nongated images using QPS™ software.

RESULTS

Volumes were significantly higher at stress in group A, at rest in group B, and similar in group C. TID ratios were significantly higher in group A vs groups B and C.

CONCLUSIONS

MPGS-derived ventricular volumes are preload dependent. The high preload of the pre-HD state may mimic ischemic TID if occurring on the stress day and create confusion if coinciding with the rest day.

Assessment of left ventricular hemodynamics and function of patients with uremia by vortex formation using vector flow mapping

A novel echocardiographic method, vector flow mapping (VFM), acquires velocity vector from color Doppler velocity data. The purpose of this study was to evaluate whether VFM could provide useful information on intracardiac flow and helpful to evaluate left ventricular (LV) function. Thirty-eight patients with uremia undergoing hemodialysis and 30 healthy volunteers were enrolled. The maximum vector velocity, maximum diameter and duration of the intracardiac vortex were measured using VFM software during systole and diastole. The maximum vector velocity of the vortex and the peak velocities at the basal septum and lateral mitral annulus measured by tissue Doppler imaging (TDI) were correlated. The maximum diameter and duration of vortex formation were significantly higher in uremic patients compared with the control group during the ejection phase (40.6 ± 7.9 cm/sec vs. 28.1 ± 3.9 cm/sec; 297.1 ± 22.1 msec vs. 145.4 ± 19.3 msec, all P < 0.001). The maximal diameters of the vortex were higher in uremic patients compared with the control group during diastole (25.6 ± 3.4 mm vs. 16.4 ± 2.1 mm; 34.3 ± 3.1 mm vs. 26.8 ± 3.9 mm; 37.5 ± 2.4 mm vs. 20.9 ± 2.1 mm; all P < 0.001). The maximum vector velocities were lower in mid-diastole and late diastole (23.6 ± 2.3 cm/sec vs. 45.2 ± 3.7 cm/sec; 31.9 ± 2.9 cm/sec vs. 54.7 ± 3.2 cm/sec, all P < 0.001). There was a correlation between the maximum vector velocity of the vortex in mid-diastole and E'/A' at the septum and lateral mitral annulus (r = 0.70, r = 0.76, P < 0.001). Vortex can be utilized to provide intracardiac dynamic information using VFM and it may be a good supplement for evaluating LV function.

Cardiac assessment in chronic kidney disease

Patients with chronic kidney disease are well recognized to develop a wide range of cardiac structural and functional abnormalities. These changes may be progressive and relate directly to a grossly aggravated risk of cardiovascular events and reduced survival. Although conventional methods of cardiac assessment have been shown to be useful, they are limited by insufficient sensitivity and specificity, to fully appreciate the overall degree of myocardial distress that is common in these patients. This article aims to review the use of established and emerging cardiac imaging tools and, in particular, their application in patients with chronic kidney disease.