Small particle cholesterol plugging up my arteries

Hi, my husband has the same issue. He had a massive heart attack in 1997 and had stents put in his left anterior descending artery. He was told his cholesterol is too dense and that it should be light and fluffy. He was told it is hereditary. He has been on nearly every statin drug but has major side effects. He has been on other cholesterol lowering drugs like Welchol also. None of them worked to lower his cholesterol to the level his doctors wanted. The cardiologist said exercise and diet is the best way to change the composition of the cholesterol. At the time of his heart attack his refraction rate was 15%. Through diet and exercise it is now at 45%. He has not had another heart attack since 1997. He has developed a fib and an episode with the a fib moved him to vfib. A defibrillator was put in his chest to regulate his heart rate. The first defibrillator activated twice and lowered his heart rate. The second time it stopped him from having another massive heart attack. This past December we were notified that the battery in the defibrillator was going bad and he had 28 days left on the battery. We had a rushed surgery to replace the defibrillator before it stopped working. After the surgery we learned that there was nothing wrong with the original unit but because it had thrown a bad code it was best to replace it.The manufacturer replaced the unit for free because the original one was supposed to last another 7 years.