Describe how the following procedures work :statins , stents , bypass surgery , heart transplant .

Statins: Statins are a class of drugs often prescribed by doctors to help lower cholesterol levels in the blood. They work by blocking the substance needed by your body to make cholesterol. This can help prevent or slow down the hardening of arteries, reducing the risk of heart attacks and strokes.

Stents: A stent is a small mesh tube that's used to treat narrow or weak arteries. The process involves inserting a catheter into an artery in the groin or arm, guided to the problem area. The stent is then placed in the blocked artery and expanded to prop it open, improving blood flow.

Bypass Surgery: This is a surgical procedure that improves blood flow to the heart. Surgeons take a blood vessel from another part of your body and use it to bypass the blocked arteries in your heart. This allows more blood and oxygen to reach the heart, reducing chest pain and the risk of heart attacks.

Heart Transplant: This is a surgical procedure performed on patients with end-stage heart failure or severe coronary artery disease. The diseased heart is removed and replaced with a healthy heart from a deceased donor. After the surgery, patients are put on lifelong medications to suppress their immune system and prevent it from attacking the new heart.