Cardiologists advance search for routine vaccine to prevent heart attacks and strokes.

2003 AUG 6 - (NewsRx.com & NewsRx.net) -- In their quest for a vaccine that may one day routinely protect against heart attacks and strokes, cardiologists at Cedars-Sinai Medical Center and their colleagues in Sweden have isolated a key step in the mechanism that leads to vascular plaque buildup and blood clot formation.

In mice genetically predisposed to quickly develop atherosclerosis, the researchers were able to trigger a protective immune response, significantly increasing the level of immunoglobulin gamma G (IgG), an antibody known to be important in protection against atherosclerosis. Immunization resulted in reduction of atherosclerosis by about 60%, compared with controls.

Heart disease is well-established as the nation's leading cause of death, and atherosclerosis is one of the major risk factors. Over the past several years, evidence has mounted that infection and inflammation contribute to this process. Researchers hope, therefore, that by attacking the first link in a complex chain of events, they can shut down a deadly process before it begins.

"Inflammation and infection have been implicated in plaque buildup and blood clot formation, processes that trigger most heart attacks and strokes. It has been observed that influenza may increase the risk of heart attacks and death, especially in the elderly," said Prediman K. Shah, MD, director of the division of cardiology and the Atherosclerosis Research Center at Cedars-Sinai.

Shah said previous experiments have shown that the influenza virus can accelerate plaque formation and arterial inflammation in mice that are genetically susceptible to high cholesterol and plaque buildup. The virus also may neutralize the protective effects of HDL, the good cholesterol.

"Recent observational studies have provided strong evidence that the flu vaccine can reduce heart attacks, stroke and death by a significant degree, and this is now being evaluated in a randomized trial. Similarly in mice, pneumococcal vaccine has been shown to reduce plaque buildup by a mechanism that does not involve pneumococcal infection," added Shah, who holds the Shapell and Webb Family Endowed Chair in Cardiology at Cedars-Sinai.

"Our goal is to develop a vaccine that will one day be administered in childhood to interrupt the inflammatory process and save lives from heart attacks and strokes," Shah said.