Heart disease kills nearly 600,000 Americans every year, making it the nation's No. 1 cause of death, according to the Centers for Disease Control and Prevention. Progress is being made to save some of these lives, though. Here are three drugs that could make a difference.

A heart failure success story
Swiss pharmaceutical firm Novartis (NYSE:NVS) looks to actually have a heart failure success story in the making with experimental drug serelaxin. In November, the company announced final data from a late-stage study of the drug at an American Heart Association meeting.

Serelaxin reduced deaths in hospitalized acute heart failure patients by 37% compared to placebo. The drug also helped prevent heart failure symptoms from worsening. Patients taking serelaxin for 48 hours via infusion experienced 45% fewer instances of worsening heart failure symptoms than did patients taking placebo.

The only negative to the clinical study was that rehospitalizations didn't decrease. However, there could even be good news hidden in those results. Dr. John Teerlink, a leader of the research, suggested that "one of the reasons there may have been an inability to show a decrease in hospitalizations is more patients were alive to be rehospitalized."

Novartis filed for regulatory approval for serelaxin in Europe in December. The company plans to submit a New Drug Application, or NDA, in the U.S. within the next couple of months.

Lowering cholesterol levels even more
High cholesterol represents a major risk factor for heart disease. Around one out of every six Americans has cholesterol levels that are too high. There are plenty of cholesterol drugs available, though. Could another one make a real difference?

The answer to that question is a resounding "yes." While it's true that several powerful cholesterol drugs are on the market, many patients still don't obtain the desired "bad" cholesterol, or LDL, reduction. Some individuals do experience lowering of their LDL levels, but further improvement would help even more in reducing risk of heart disease.

Sanofi (NYSE:SNY) and Regeneron Pharmaceuticals (NASDAQ:REGN) have developed a new drug that could lower LDL even more effectively than popular statin drugs. In November, the two companies announced enrollment in a large late-stage clinical trial to study the effects of an antibody that could lower LDL levels by inhibiting an enzyme called PCSK9 that is involved in the production of cholesterol.

Targeting PCSK9 appears to be a promising approach for reducing cholesterol. Several other pharmaceutical companies are also developing drugs that inhibit the enzyme, including Pfizer (NYSE:PFE) and Roche. However, Sanofi and Regeneron maintain a lead at this point.

Teaching an old dog new tricks
Pfizer's Inspra gained FDA approval all the way back in 2002 to treat high blood pressure and in 2003 for improving the survival of patients who had a heart attack. How is it possible that a drug on the market for so long could still be viewed as a potential game changer for heart disease?

A month ago, Pfizer announced results from a new clinical study of Inspra. More than 1,000 patients who had a heart attack caused by complete blockage of an artery participated in this study. Researchers found that patients taking Inspra achieved nearly 43% improvement over those taking placebo in avoiding negative outcomes such as death from cardiovascular causes, rehospitalization due to heart failure, or other indicators of heart failure after around 10 months following treatment.

The key for Inspra will be whether these impressive results over a relatively short term can be sustained over longer periods. Dr. Miguel Quinones, chair of cardiology at Methodist DeBakey Heart and Vascular Center in Houston, noted that the drug could truly become a game changer if significant outcomes can be achieved after three to five years.

Good news
None of these drugs can change the game until they're actually in the game. Hurdles remain for all of them before they can be available to patients for the intended usage. The progress made so far, though, is clearly good news.

And there's more good news. There are plenty of other experimental treatments in development. Heart disease continues to kill more Americans than any other factor, but the possibilities seem bright for thousands of lives to be saved with new potential game-changing drugs on the way.
