I passed on chemo because both of my surgeons were very confident that all cancer had been removed.
Instead, I opted for blood tests and CT Scans every 4 months.
I suggested this plan and they agreed.

I had a 9 inch sigmoid colon resection with one of a dozen lymph nodes involved.
My colon cancer had also metastasized to my lower right lung. There I had a lung wedge resection of about 6 square inches and with all margins clear.

So now 15 months later all is good. I am happy with my decision and I do know that cancer could return. But it doesn't have to be colon or lung, it could be any cancer.
And as such, it would not necessarily be from not having chemo for many months or even years without chemo.
(There are people who had chemo for a year and cancer quickly returned thereafter).

I have never advised anyone to not have chemo.
This is a very personal decision and every situation is different.
Your situation is very unique at a young age and having a Cardiovascular history.
Yes, it is a tough decision.
I would pass until there is reason not to.
I really wish the very best for you going forward!
May you receive a blessing for a healthy life !!