LONDON -- A painless heart attack, when sufferers have shortness of breath and discomfort in the chest but feel no ache, can be the most deadly, Reuters quoted British doctors as saying on Tuesday.

Heart attacks without pain are common and people who have them are twice as likely to die within a month and have three times the risk of dying within a year than other patients because they may not get the best treatment.

"We have shown that this subgroup of patients represents a high-risk population that is less likely to receive treatment strategies of proven diagnostic benefit," said Professor Alistair Hall of Leeds General Infirmary in northern England.

Hall and his colleagues studied nearly 2000 patients who had been treated for a heart attack in 20 hospitals in northern England during a three-month period. Slightly more than 20 percent did not have chest pains during the attack.

When the researchers compared the treatment and survival of the two groups of patients, those who had chest pains lived longer than those who did not.

"This may result in part from a failure to use beneficial treatment strategies," Hall said in a report in the medical journal **** Heart ***.

In a separate study researchers from the Royal Free and UCL Medical School in London showed that British men are just as likely to be diagnosed with coronary heart disease (CHD) today as they were 20 years ago, despite improved knowledge about the illness and ways to prevent it.

"The proportion of middle aged men with a history of diagnosed CHD had not changed discernibly," said Fiona Lampe of the Royal Free and UCL Medical School in London, adding that the need for secondary prevention is as great as ever.

Heart disease is the major cause of death in most Western countries. Smoking, high blood pressure and a family history of disease are major risk factors.