Actually fibrosis shouldn't be an issue. The tryptamines in general have the fibrosis problem because of 5-HT2B activation, or as Wiki puts it "5-HT2B receptor stimulation can also lead to pathological proliferation of cardiac valves fibroblasts", but Lisuride is an antagonist at this receptor.
In fact dear old Wiki says that:
"5-HT2B antagonists have previously been proposed as treatment for migraine headaches... but development was not continued. More recent research has focused on possible application of 5-HT2B antagonists as treatments for chronic heart disease. [but] Serotonin 5-HT2B receptors inhibit liver regeneration and may have effects on immune system function."
So Lisuride probably is nasty in chronic use, but not for the heart.