Hello 
As you have said that you want to loose weight , with a known 
heart disease ( stent ) , i dont know your BMI , as i need to know your height , then i can grade you in group and can tell your obesity morbidity 
I also woulld not recommend to take coffe pills , as they havee nicotine , caffine both are symapthetomimetics , cause fast 
heart rate at all times , and your heart blood supply is already less.Other reason are fast arrhythmias which can cause SCD ( 
sudden cardiac death ) especially in patients who had 
angioplasty.
Herballife formula can be used , keeping in check with your kidney functions and liver functions monthly , as herbal product are known to cause liver and kidney failure
You can use medical drugs which are heart safe like reductil , appetite suppresants drugs etc 
Check your thyroid level , as 
hypothyroidism can cause weight increase , may be your thyroxine dose is less?( actual dose is 1.6 x body weight)
Hope this helps