I was wondering if in your experience 5htp needed to also be taken with a decarboxylase inhibitor?

If taking very high doses of 5-hydroxytryptophan (5-HTP) then it would probably be a really good idea to reduce the possible risk of heart valve damage and hypertension.  In lower doses though I don't believe this is really an issue.

Have you ever heard of people having heart problems from taking 5htp in your experience in medicine?

No, I have never seen any cases nor evidence of any reports of these issues with 5-HTP.  But again this is not likely an issue unless taking high levels.  Then there is a risk of damage such as we saw in the Phen fen fiasco.

I am a chronically depressed person and have been very impressed personally from 5htp's effects but have been cautious to pursue further due to this concern of free serotonin causing cardiac fibrosis problems due to production of free serotonin in the body.

There are various other options.  These include using chamomile, which is the highest herbal source of tryptophan.  Or TMG, which is a safe methyl donor for both the production of various neurotransmitters, for better nutrient absorption, for hormone regulation, etc.  Keep in mind that depression has numerous causes, not just low serotonin.  Therefore, raising serotonin levels will not work for all cases of depression.