Casual vs ambulatory blood pressure readings seem to account for the difference between what is reported in Table S2 and what is shown in the main paper. I don't know which kind of reading is more clinically significant or reliable. A little worrying that its not seen in the ambulatory too.

Comparing group means might not be quite so informative in any case, because of baseline effects (e.g. you'd want to do paired tests I think to compare the diffs)