I don't think there is a physiologic reason, I suspect it is for the same reason that CV outcomes have historically been less good for women than men--heart disease has tended to be overlooked and manifests somewhat differently in women, thus they often present with more advanced disease.
I feel like this trial is a little bit of a gimmick and also wouldn't provide any evidence for a sex differential obviously.
Women may be at greater risk of procedural complications following rotational atherectomy. These include periprocedural bleeding episodes and coronary perforation leading to cardiac tamponade.
SWAV found the women in their trials using IVL did noticeably better compared to women in trials using atherectomy ....so they wanted to do one exclusively in women with larger numbers to confirm ( from memory ) . Sell off today I think related to CFO selling around 2,000 shares open market ...which he probably wouldn't have done if a BO was imminent . JMO Kiwi