The ingredient of Viagra is sildenafil, and you can take sildenafil appropriately if you have had a stent for three years if your condition is stable, but you should take it under the guidance of your doctor. Sildenafil has the effect of dilating blood vessels and can be used to treat patients with erectile dysfunction. Adverse reactions such as weakness and pain may occur after using this drug. It should not be used concurrently with nitrates and should be used with caution in patients with heart failure. Patients who have undergone cardiac stenting can take sildenafil appropriately if their condition is stable, but they should be careful to start with a small dose, pay attention to the adverse reactions and monitor the blood pressure level during the course of taking the drug. Before taking sildenafil, patients should have their condition evaluated under the guidance of a cardiologist, and choose the right dosage under the guidance of the physician to avoid accidents.