By DR. TIFFANY CHAO, ABC News Medical Unit

Severe heart attacks may not be as deadly as they used to be, according to new research.

A new French study demonstrated that in patients who are hospitalized for severe heart attacks - technically known as ST-elevation myocardial infarctions - the chances of dying within 30 days dropped from 13.7 percent in 1995 to 4.4 percent in 2010, an improvement of 68 percent.

Researchers looked at data from nationwide registries in France in 1995, 2000, 2005 and 2010 which included more than 6,700 patients who had heart attacks and were admitted to intensive care units. They analyzed the data and found that the improvement in survival was likely related to a number of factors, including changes in demographics, more timely presentation to hospitals, improvements in medications and treatments, and higher rates of stenting open up blocked arteries.

The reduced chance of dying is "consistent with many other sources in the United States and Europe," reported the lead author, Dr. Etienne Puymirat, in the article published today by the Journal of the American Medical Association (JAMA). So even though the study was conducted in France, cardiologists in the U.S. report similar experiences.

"This is certainly consistent with what we're seeing in the United States," said Dr. Randall Zusman, a cardiologist at Massachusetts General Hospital. "If they reach the hospital, they will likely leave the hospital, so it's so important that people recognize the importance to coming and being assessed as soon as possible."

The authors found that a number of improved preventive strategies and advances in treatment have helped heart attack victims' survival.

On average, patients came to the hospitals much sooner after the onset of symptoms like chest pain - perhaps because public health efforts have increased awareness that symptoms like chest pain or pressure, shortness of breath, or pain radiating down the arms, back, neck or jaw, can be symptoms of a heart attack.

Once patients arrived at the hospital, there was a 50 percent increase in therapy to fix coronary artery blockages, usually with a technique involving the insertion of a tiny metal sleeve known as a stent to prop the blood vessels open. In addition, there was more efficient use of effective medications such as beta-blockers, ACE inhibitors, statins and blood-thinning medications.

"Things like the increased use of [stenting and] the increased use of better medications at higher doses are all going to be applicable to our practices," said Dr. Carl Lavie, the medical director of cardiac rehabilitation and prevention at Ochsner Clinic Foundation and Hospital in New Orleans. "There might even be better drugs being used today. These big reductions in mortality - you'd actually expect that."

Another finding was the change in demographics of who is having a heart attack. The study found that the proportion of younger women having heart attacks more than doubled from 11.8 percent in 1995 to 25.5 percent in 2010. The authors attributed this to the prevalence of smoking and obesity.

"The big message for me is that we are geniuses as doctors and interventionalists in saving the lives of people with acute myocardial infarctions, but the patients themselves contribute to their own disease by not paying attention to risk factors," said Dr. Marianne Legato, founder and director of the Foundation for Gender-Specific Medicine in New York. "Young women who smoke put themselves at significant risk."

According to the study, "These observations suggest that future reductions in the incidence and mortality related to [heart attacks] will need specific targeting of preventive measures toward younger women and possibly younger men."

Mass General Hospital's Zusman agreed that public health efforts should be made to encourage people to seek out care when they have symptoms.

"The things we're doing - the new drugs, aggressive intervention systems - are working," he said. "But the patient can't benefit from them unless they come to the hospital."