الفهرس 
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Abstract
End stage renal disease (ESRD) represents a major public health problem. According to United State Renal Data System (USRDS) Registry, its incidence and prevalence is increasing over the last years.
ESRD patients are at increased risk for cardiovascular mortality and all-cause mortality. This risk increases with deterioration of GFR and at the start of dialysis.
Cardiovascular mortality is 3.5 times higher in renal patients than in the general population. Heart failure represents 15%, myocardial infarction 10%, uremic pericarditis 3% of dialysis associated mortality. Sudden cardiac death accounts for 60% of cardiovascular mortality.
Left ventricular hypertrophy (LVH) is a common finding in ESRD patients; it is a component of uremic cardiomyopathy and an independent risk factor for sudden cardiac death, heart failure and cardiac arrhythmias in the general population and HD patients.
Left ventricular hypertrophy, left ventricular systolic dysfunction and also significant diastolic dysfunction all are independent predictors of cardiovascular outcome and adverse cardiovascular events in dialysis patients. Moreover, regression of LVH with a reduction of LVM has been associated with favorable outcomes such as lowered likelihood of developing heart failure, improvement of systolic function, reduction of the risk of ventricular arrhythmia, atrial fibrillation, and lower all-cause mortality.
The aim of this study was to assess the role of CMR and echocardiography in evaluation of left ventricular geometry, and function and assessment of myocardial hemosiderosis in ESRD patients on maintenance hemodialysis.
The study included 45 subjects, who were divided into 2 groups: 30 ESRD patients on maintenance haemodialysis and 15 healthy subjects as a control.
After obtaining an informed consent, the patients were subjected to history taking, clinical examination, laboratory investigations including routine laboratory investigations:- (CBC, lipid profile, renal functions, hsCRP and NT pro BNP). In addition, all patients were assessed using echo and CMR.
The study showed increased serum creatinine, urea, uric acid, phosphorus, Ca × Po4 product, s. iron, s. ferritin, transferrin saturation, TG, cholesterol, LDL, hsCRP and NT pro BNP level in the HD group in comparison to the control group, while it showed decreased hemoglobin, calcium, albumin, TIBC and HDL in the HD group in comparison to the control group.
Echocardiography has shown that LA diameter, LVEDD, LVESD, LVM, LVMI were all significantly greater in group I than in group ΙΙ.
Left ventricular dilatation was found in 11 cases (36.7%) in group I and none (0%) in group ΙΙ. Valvular heart disease was found in 11 cases (36.7%) in group I and none (0%) in group ΙΙ, and pericardial effusion was present in 1 case (3.3%) in group Ι and none (0%) in group ΙΙ.
The mean systolic function by EF by both ECHO and CMR was lower in group I in comparison to group ΙΙ; the difference was not statistically significant by ECHO measurement, while it was statistically significant by CMR. Systolic dysfunction by ECHO was found in 3 cases (10%) of group I and none (0 %) in group ΙΙ, while diastolic dysfunction was found in 21 cases (70%) of group I and 2 cases (13.3 %) in group ΙΙ. The difference was statistically significant with a p value < 0.001. Systolic dysfunction by CMR was found in 11 cases (36.7) in group I in comparison to none (0%) in group ΙΙ.
LVM, LVMI and mass to cavity ratio (mass / LV EDV) were all significantly greater in group I in comparison to group ΙΙ.
Left ventricular geometry was normal in 7 cases (23.3 %) in group I and 6 cases (40 %) in group ΙΙ, concentric remodeling was present in 3 cases (10%) in group Ι and 5 cases (33.3) in group ΙΙ. In group Ι, 66.6% of patients met ECHO criteria for LVH (23.3 % eccentric LVH, 43.3% concentric LVH), while in group ΙΙ, LVH was designated by ECHO in 26.6% of patients (13.3% eccentric LVH, 13.3% concentric LVH). On the other hand, by CMR, LVH criteria were met by 36.7% in group Ι (6.7% concentric LVH, 30% eccentric LVH) and none (0%) in group ΙΙ. The Cohen’s kappa for LVH detection in group Ι reflected moderate agreement, while Cohen’s kappa for LVH geometry classification as concentric and eccentric reflected fair agreement.
LVH by ECHO as indicated by LVMI > 95 gm/m2 in females and > 115 gm/m2 in males, was mild in 8 cases (26.7 %) in group I and 4 cases (26.7 %) in group ΙΙ, moderate in 1 case (3.3 %) in group I and none (0%) in group ΙΙ, and severe in 11 cases (36.7%) in group I and none (0 %) in group ΙΙ.
There was a statistically insignificant negative correlation between NT pro BNP serum level and EF by ECHO, while there was a statistically significant negative correlation between NT pro BNP serum level and fractional shortening.
There was a statistically significant positive correlation between NT pro BNP serum level and LA diameter, LVEDD, LVESD, LVM, LVMI by echocardiography, LVM, LVMI, mass to cavity ratio (mass/LVEDV) by CMR, while there was a statistically significant negative correlation between NT pro BNP serum level and EF by CMR. The mean serum level of NT pro BNP was significantly higher in patients with diastolic dysfunction in comparison to those without diastolic dysfunction.
There was a statistically significant positive correlation between ECHO and CMR as regard EF, LVM and LVMI.
Bland-Altman analysis demonstrated wider agreement limits in EF, LVM and LVMI measurements by ECHO and CMR in group Ι than in group Π, the Cohen’s kappa for the EF in group Ι reflected fair agreement, the Cohen’s kappa for LVM in group Ι reflected poor agreement, while the Cohen’s kappa for LVMI in group Ι reflected fair agreement.
Cardiac iron deposition was present only in one case (3.3%) in group I and none (0%) in group ΙΙ. While hepatic iron deposition was present only in group I in 21 cases (70%) out of 30 cases. According to the severity of deposition, there was only one case (3.3%) with minimal hepatic iron deposition, 4 cases (13.3%) with mild hepatic iron deposition, 5 cases (16.7%) with mild to moderate hepatic iron deposition and 11 cases (36.7%) with moderate hepatic iron deposition.
The mean serum iron, ferritin and transferrin saturation were all significantly higher in patients with hepatic iron deposition in comparison to those without hepatic iron deposition, while the mean serum TIBC was significantly lower in patients with hepatic iron deposition in comparison to those without hepatic iron deposition.
The mean liver iron concentration was significantly higher in group I in comparison to group ΙΙ. There was a statistically significant positive correlation between LIC and serum iron level, serum transferrin saturation, serum ferritin, CRP, while there was statistically significant negative correlation between LIC and TIBC.
The mean LVM, LVMI, LVEDD, LVESD by echocardiography, and LVM, LVMI by CMR, serum hsCRP, and the mean serum NT pro BNP were all higher in patients with hepatic iron deposition in comparison to those without hepatic iron deposition but the difference was not significant, while the mean mass to cavity ratio (mass/ LVEDV) was significantly higher in patients with hepatic iron deposition in comparison to those without hepatic iron deposition.
The mean EF by ECHO was lower in patients with hepatic iron deposition in comparison to those without hepatic iron deposition but the difference was not significant, while the mean EF by CMR was higher in patients with hepatic iron deposition in comparison to those without hepatic iron deposition and the difference was not significant.
In conclusion, patient on hemodialysis are plagued with multiple cardiovascular diseases including LVH. Although commonly diagnosed using echocardiography, the present study showed that echo overestimated LVM, LVMI and the presence of LVH. Therefore, CMR is a superior method to evaluate for the presence of LVH. MRI also gives the opportunity to detect tissue iron deposition, which we found to be common in the studied patients. Further study to the impact of iron tissue deposition on the cardiovascular as well as the overall health of dialysis patients is warranted.