Does your uncle have Mitral Valve Prolapse? Is he experiencing Mitral Regurgitation where the blood leaks backwards? Does your uncle have any other diseases that you are aware of? You mentioned HDL increase..
Make sure he avoids all trans or partially trans fatty acids. Trans fats hurt out bodies, reduce HDL and increase LDL - but I don't really believe these markers are sole predictors of anything. Does he eat fish? Wild caught, clean water fish with high omega 3's should help. Nicotinic acid (niacin) helps to raise HDL, but I would prefer high niacin, natural foods instead.
Basically, HDL carry lipids from bodily tissues, while LDL carry lipids into bodily tissue. I believe that both are equally important in the homeostasis of our cellular structures. Cholesterol is essential for life.
Arterial plaque is usually oxidized cholesterol, commonly found in cooked cholesterol foods.
The mitral valve is a constantly active area of the heart, it may require some type of conventional medicine intervention.
Magnesium may help the mitral valve, mag-malate is Hv's favorite for many reasons. Don't use the cheap stuff if you decide to offer a supplement like any oxides or carbonates.