Heart disease is likely caused in the after-eating, postprandial period. That's why the practice of grazing, eating many small meals throughout the day, can potentially increase heart disease risk. Eating often can lead to the phenomenon I call triglyceride and chylomicron "stacking," or the piling up of postprandial breakdown products in the blood stream.
Different fatty acid fractions generate different postprandial patterns. But so do different sugars. Fructose, in particular, is an especially potent agent that magnifies the postprandial patterns. (See Goodbye, fructose.)
Take a look at the graphs from the exhaustive University of California study by Stanhope et al, 2009:
From Stanhope KL et al, J Clin Invest 2009. Click on image to make larger.
The left graphs show the triglyceride effects of adding glucose-sweetened drinks (not sucrose) to the study participants' diets. The right graphs show the triglyceride effects of adding fructose-sweetened drinks.
Note that fructose causes enormous "stacking" of triglycerides, meaning that postprandial chylomicrons and VLDL particles are accumulating. (This study also showed a 4-fold greater increase in abdominal fat and 45% increase in small LDL particles with fructose.)
It means that low-fat salad dressings, sodas, ketchup, spaghetti sauce, and all the other foods made with high-fructose corn syrup not only make you fat, but also magnifies the severity of postprandial lipoprotein stacking, a phenomenon that leads to more atherosclerotic plaque.