There was a single-centre open label proof of concept study in Greece in 2015 to study this in humans. It seems that clopidogrel worsened markers of endothelial function. There was no effect on serotonin levels but instead caused new digital ulcers in 3 patients (out of 12), which led to the termination of the study.

Results were published in BMC Musculoskelet Disord. 2016 May 17;17:213

Hope this helps.

Thank you Kyrillos. Surprising, because you would expect it to help

Bw

Robert