Download comparison of echocardiographic and pulse wave parameters

COMPARISON OF ECHOCARDIOGRAPHIC AND PULSE WAVE PARAMETERS
BETWEEN HAEMODIALYSIS PATIENT OF DIFFERENT AGES
Introduction: Both haemodialysis and ageing are associated with significant adverse
cardiovascular effects. We hypothesised that the effects of dialysis would mean that younger
patients would have comparable cardiovascular structural abnormalities to their older peers,
despite the greater ageing of the heart in the latter group.
Method: A single centre prospective study of haemodialysis patients aged >18 years. Patients
underwent trans-thoracic echocardiography and pulse wave assessment (Vicorder®) after
written informed consent had been gained. Investigations were performed on a non-dialysis day
when clinically well. Patients were divided into 4 age groups (table 1) and between group
comparisons of parameters made using one-way ANOVA. Sample size calculations determined
a requirement of 40 patients per group to detect a 30% difference at power 80%, α<0.05.
Results: There were 219 patients in the study (age 62 ± 14 years, LVEF 62 ± 16%, PWV 8.8 ±
2.2m/s). Complete overall characteristics and those for each age group is found in table 1. There
were no statistically significant differences in any measured parameter. The youngest patient
group (<55 years) had numerically higher pulse wave velocity (PWV) and had been on dialysis
for the longest (median 6 years, range 0 – 31 years, p<0.01).
Table 1. Echocardiographic and pulse wave comparison of haemodialysis patients of different
age groups, with between group comparison.
219
62 ± 14
4 (0 - 31)
<55
61
44 ± 9
6 (0 - 31)
Age category
55-65
65-75
53
69
60 ± 3
70 ± 3
3 (0 - 16)
2 (0 - 15)
>75
36
79 ± 4
2 (0 - 7)
<0.01
35 ± 11
109 ± 38
62 ± 16
4.2 ± 0.8
52 ± 20
34 ± 10
107 ± 32
60 ± 16
4.1 ± 0.9
49 ± 19
38 ± 9
113 ± 42
67 ± 11
4.2 ± 0.7
55 ± 18
34 ± 14
109 ± 41
60 ± 19
4.4 ± 0.8
52 ± 21
35 ± 10
108 ± 36
62 ± 14
4.0 ± 0.8
51 ± 22
0.17
0.88
0.07
0.08
0.43
8.8 ± 2.2
25 ± 9
74 ± 13
141 ± 23
70 ± 11
100 ± 15
9.2 ± 2.4
26 ± 9
76 ± 13
144 ± 24
69 ± 11
101 ± 16
8.9 ± 2.5
25 ± 9
74 ± 12
143 ± 23
72 ± 10
101 ± 15
8.6 ± 1.8
26 ± 8
74 ± 13
141 ± 23
70 ± 13
99 ± 15
8.3 ± 1.7
23 ± 9
75 ± 13
135 ± 23
69 ± 11
97 ± 16
0.25
0.39
0.78
0.29
0.45
0.66
Overall
N
Age (years)
Time on dialysis (yrs)
Echocardiography
MWFS
LVEDV
Teichholz LVEF (%)
LAd (cm)
LVMIht
Pulse wave assessment
PWV
AIx
HR
Central SBP
Central DBP
MAP (mmHg)
p
Key: MWFS = midwall fractional shortening, LVEDV = left ventricular end diastolic volume, LVEF =
left ventricular ejection fraction, LVMIht = LV mass indexed to height, LAd = left atrial diameter, AIx =
augmentation index (adjusted for gender and heart rate), HR = resting heart rate, SBP = systolic blood
pressure, DBP = diastolic blood pressure, MAP = mean arterial pressure).
Conclusion: The overall pattern of echocardiographic and pulse wave characteristics is
consistent amongst patients of age groups. This is suggestive that the pathological
cardiovascular effects of prolonged dialysis vintage to which younger patients are more exposed
are echocardiographically similar to those found in the ageing heart. This is within the context
of a slightly underpowered study.