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A larger, wealthier, and longer-living population could cause heart disease to become an even more pressing crisis than it already is, and that's a frightening prospect given that heart disease already claims the lives of more than 600,000 people in the U.S. alone every year.

Amgen (NASDAQ:AMGN), Regeneron (NASDAQ:REGN) and Aegerion (NASDAQ:AEGR) are among a slate of companies marketing and developing next-generation, cholesterol-curbing treatments that may keep this common disease in check; however, only two may be worthy of putting in an investor portfolio.

1. Amgen
Amgen has a long track record of success that includes top-selling medications used to treat anemia, and this year Amgen is making a big splash with two recently approved drugs targeting heart disease.

In April, the FDA approved Amgen's Corlanor as a therapy to reduce the likelihood of hospitalization for worsening heart failure in patients with chronic heart disease. In August, the agency gave Amgen the go-ahead to begin marketing Repatha, a cholesterol-lowering drug that can be used in patients with tough-to-treat cholesterol levels.

Although Corlanor and Repatha are both expected to become billion-dollar blockbusters, the fact that Repatha works differently from widely used cholesterol medicines known as statins  makes it arguably more intriguing.

While statins lower cholesterol production in the liver, Repatha reduces the ability for the PCSK9 protein to eliminate cholesterol receptors in the liver, which allows the patient to clear more bad cholesterol from the bloodstream. Since Repatha has a different mechanism of action, it can be used either as a monotherapy or alongside statins, and that has people thinking that Repatha's efficacy could lead to its use in far more patients than its initial approval would seem to suggest.

In addition to potential growth tied to Corlanor and Repatha, investors could also eventually benefit from another cholesterol-lowering drug that Amgen recently acquired when it spent over $300 million in cash as part of a $1.5 billion deal to buy privately held Dezima Pharma. In a phase 2b clinical trial, Dezima's TA-8995 lowered bad cholesterol by 45% to 48% versus baseline.

2. Regeneron Pharmaceuticals
If there's one stock investors wish they'd owned over the past five years, it's got to be Regeneron Pharmaceuticals.

Because of growing use of Eylea, a medicine used to treat vision loss in patients with wet-stage age-related macular degeneration and diabetic macular edema, Regeneron's shares have soared 216% since 2012.

This year, Regeneron investors could get an additional bump following the FDA's approval of Praluent, a PCSK9 drug that won FDA approval in July and works similarly to Amgen's Repatha.

Although Praluent and Repatha work in the same manner and they delivered comparable efficacy in trials, industry estimates suggest that as many as 10 million patients could qualify for PCSK9 therapy, and given that the price tag on these drugs is north of $14,000 per year, the market should be able to support both of these companies. 

However, because Amgen is a much larger company than Regeneron, Repatha isn't as likely to move its needle as much as Praluent could move the needle for Regeneron and that might make Regeneron's shares a better buy for risk-tolerant investors.

3. Aegerion Pharma
Overwhelmingly good news for Amgen and Regeneron could be bad news for Aegerion Pharma.

Aegerion Pharma's Juxtapid has had a lock on treating tough-to-treat cholesterol since it won approval in 2012, but now that Repatha and Praluent have proved that they can reduce cholesterol in the same patients, it's uncertain how many doctors will favor Juxtapid over these two other options.

Compounding Aegerion's risk is that Amgen and Regeneron's drugs are priced at a significant discount to Juxtapid's sky-high $300,000 plus per year cost.

Because the price difference between Juxtapid and these PCSK9 drugs is significant, the fact that Juxtapid is taken orally, rather than injected like Repatha and  Praluent, may not be enough of a benefit for Aegerion to maintain its market share, and that makes this too risky of a stock for me to want to own.

Looking forward
Cholesterol-busting drugs can provide a benefit to patients, but it's uncertain how big of a benefit these drugs may offer patients.

Although statins are proven in clinical trials to reduce the risk of cardiovascular events, that's not the case for these three drugs. Amgen and Regeneron are both conducting cardiovascular outcomes studies; however, and if those studies pan out, then Repatha and Praluent could make an even bigger positive impact on heart disease than is currently projected, which could make both of these companies even more attractive to own for the long haul.

Todd Campbell has no position in any stocks mentioned. Todd Campbell owns E.B. Capital Markets, LLC. E.B. Capital's clients may have positions in the companies mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.