The primary endpoint was LVM on
CMR. We followed the recommendations of Grothues et
al. (16), which advised that 30 patients would be needed to
detect a 10-g change in LVM at 90% power, on the basis of
a reproducibility figure of 3.6%. In fact, we doubled our
numbers to 60 patients and then to 66 patients to account
for 10% dropouts. We doubled our numbers because we
thought 30 patients was a bit tight and because it would be
challenging to regress LVM by 10 g in only 9 months with
no expected change in BP. Using Grothues et al. reproducibility
figure, our 60 patients study had 90% power to detect
a 5-g change in LVM. We were also aware that this figure
matched the differential change in LVMI between the treatments
in the echo substudy of the LIFE (Losartan Intervention
For Endpoint reduction in hypertension) study (7).
Data for continuous variables are presented as mean
SD for normally distributed data and median and interquartile
range for non-normally distributed data. Categorical
data are expressed as numbers (%). Comparisons between
continuous variables were analyzed using the Student t test
or Mann-Whitney U test while categorical variables were
analyzed using chi-square test. Correlation was performed
using Pearson’s or Spearman’s method.
All statistical analyses were undertaken using SPSS version
18.0 (SPSS, Chicago, Illinois). A 2-sided p value
0.05 was considered statistically significant.