Adults with severe obesity (BMI >35) and a prior heart attack who undergo weight-reduction surgery may lower their risk of a second heart attack, major cardiovascular event, heart failure and death. The effect weight-reduction surgery had on the patients' weight, blood pressure, cholesterol and A1C (a Type 2 diabetes marker) seems to play a role in decreasing the risk of heart attack and death.

Source: Weight-reduction surgery for severely obese adults may prevent second heart attack, death