When is open heart surgery needed vs less invasive options?

Many factors: If the ohs is for coronary artery blockage, surgery is indicated for life threatening disease (involving the left main artery) or multiple blockages (involving 3 or more arteries) that for technical reasons can't be adequately dilated and stented. If the ohs is for a valve, it depends on which valve, what's wrong with the valve, and the severity of symptoms.

Age and severity: Coronary artery disease is now often treated with stents placed during a cardiac cath, instead of open heart surgery. What is unclear is whether stents last as long as bypass, or if they are as good for multiple vessle disease. Younger patients, mand patients with more severe multiple vessel disease may do better with an open heart bypass.