LP(a) is the most important genetic marker for heart disease and can be measured directly via phenotype.

“the most important genetic test that you would look at from a heart disease standpoint would be LP little-a which we've spoken about at length so if you have the LP a gene which honestly somewhere between about eight and twelve percent of the population does maybe even higher that's important to know but guess what you don't need a genetic test to do that you can just measure the phenotype meaning you don't need to know if you have the LP a gene you can actually measure LP little a it's even easier to measure”