Testosterone supplementation has been shown to increase muscle mass and strength in healthy older men. However, a new study, reported in the New England Journal of Medicine 1), showed that in older men (>74 yo), testosterone treatment was associated with an significantly higher rate of cardiovascular adverse events.
High levels of high density lipoprotein (HDL) (“good”) cholesterol in males decrease during adolescence and after treatment with testosterone derivatives. That in turn increases the risk of cholesterol related complications, specifically atherosclerosis & coronary artery disease (CAD).
In that sense, a testosterone shot increases your risks for coronary artery disease (CAD). Whether that causes an increased risk of stent failure by itself is debatable. Stents or coronary bypass surgery do not treat the cause of atherosclerosis. If successful, these procedures restore the blood flow back to normal, but the disease that causes the atherosclerosis remains the untreated. The only therapy available at present is with diet & exercise, weight loss, cessation of smoking and cholesterol treatments.
The nature of stents is this: they over-stretch and destroy the artery locally. Because of that, there is response to repair itself (like a scar)that will create a new type of of blockage. The latest stents (drug eluting stents) try to prevent this by leaching cancer chemo therapy drugs into the wall of the artery. Even so, the recurrence rate is in the order of 10%/year. Stents have not proven to prolong life in patients with CAD. In a recent large study of patients with stable angina, the rates of acute MI, stroke, death, and hospitalizations were slightly higher with stents than with medical therapy alone.
Bypass surgery is a bigger procedure, but has a much higher success rate, and is superior to stenting in almost every type of multi-vessel or left main Coronary Artery Disease (CAD), as well as in patients with diminished heart function and diabetics.
Your risk for heart disease & stroke:
The net result of your question is as far as cardiovascular risk is concerned, Testosterone treatment is probably not worth it.
Hope this helps,