Every surgery is associated with certain amount of risk and it increases with number and duration of comorbidities like diabetes, hypertension, heart diseases but surgery needs to be done as and when required taking all precautions. Gall bladder stone can form because of multiple reasons some are known and many unknown, few of known factors are female sex, obesity, age, high cholesterol and any systemic illness including cardiac diseases.

That would depend on time since heart surgery, present status of heart function, and other co existing medical conditions. No cause of formation of gallstones specific to heart condition. No alternative to surgery.