"We are very excited about the meeting, there is going to be a lot of very important science presentations and some of them will transform the way we practice as we are going forward," said cardiologist Marc Shelton, chair of the American College of Cardiology's 57th annual gathering.
The results of dozens of clinical trials will be unveiled during the three-and-a half-day meeting, opening Saturday and expected to draw some 18,000 participants, Shelton told reporters.
Of particular note is a forum on the controversial ENHANCE trial comparing US pharmaceutical giant Merck's anti-cholesterol drug Vytorin with simvastatin, a predecessor from the same group that is now available in a low-cost generic version.
Although the clinical trial was concluded in 2006, Merck and Schering-Plough -- the maker of Zetia, another cholesterol-buster combined with simvastatin to create Vytorin -- waited until January 2008 to release the findings.
They show little apparent difference between Vytorin and simvastatin in patients with very high levels of cholesterol, although the former is five times as expensive as the latter.
The revelation caused sales of Vytorin and Zetia to drop by 18 percent and sent shares of the two pharmaceuticals plunging.
Following an aggressive advertising campaign launched in 2006, sales of Vytorin and Zetia had doubled in two years, bringing in five billion dollars world wide in 2007.
The results of the ENHANCE clinical trial will be discussed in a forum of eminent cardiologists Sunday, the second day of the conference.
"The goal that we have given to the panel members is to, at the end of the discussions, come up with a recommendation for how they would treat patients when they go home on Wednesday after the meeting," Shelton said.
A congressional panel has also launched a fraud investigation of the two companies.
Statins such as simvastatin, Pfizer's lipitor, and AstraZeneca's crestor act by blocking an enzyme in the liver, while Zetia absorbs cholesterol in the digestive tract.
The latter approach has not been proved to lower the risk of heart attack by reducing arterial plaque.
Several other important studies will be presented in Chicago this weekend, Shelton said.
A vast international clinical trial dubbed ONTARGET should provide epidemiological data on the best treatment for high blood pressure, after testing anti-hypertension medicines Telmisartan and Ramipril separately and in combination.
Other clinical trials involve hypertension treatment in patients over age 80 with obesity or high-risk diabetes.
Cardiovascular disease is the chief cause of death in the United States, claiming more than 900,000 lives each year.
It was responsible for 17.5 million deaths in the world in 2005, 30 percent of the total mortality, according to the World Health Organization.