Stephanie Headley was diagnosed in 2002 with systematic scleroderma, a terminal disorder that causes the skin and inner organs to harden and eventually fail.
Headley, who in 2009 was given five years to live, had been pinning her hopes on an expensive treatment involving stem cell therapy in the United States.
Her story first made headlines in July after she received a $128,000 bank draft from an anonymous donor to pay for the procedure, which isn't covered under the Ontario Health Insurance Plan (OHIP).
Heart wasn't strong enough
Headley left for Chicago in October and had planned to begin the treatment in January.
But on Thursday, she confirmed that preliminary tests had discovered her heart wasn't strong enough for the therapy.
Headley says she now plans to use the money on other treatments at home that could prolong her life, and to raise awareness about her disease and stem cell therapy.