The team, led by Dr Fiona Lampe from the Royal Free and University College Medical School in London, UK, examined rates of different forms of coronary heart disease (CHD) among 7735 men, aged 40–59 years in 1979–80, from 24 general practices located in various UK towns.

Over the subsequent 20 years, the researchers found that the rate of major coronary events fell substantially, by an average of 3.6% per year. However, angina diagnosis rates increased by 2.6% per year over this period, resulting in no significant drop in the rate of in CHD overall.

The fall in major coronary events occurred across all categories of events – fatal, nonfatal, first and recurrent, while first angina diagnoses increased for both uncomplicated angina and angina after a heart attack.

Death rates within 28 days of a first major coronary event dropped by 1.4% per year after taking into account the age of the participants, the researchers note.

Writing in the British Medical Journal, the researchers conclude: "The continued decline in the rate of major coronary events among British men is encouraging, and shows that favourable changes in both risk factors and treatment have affected the incidence and prognosis of myocardial infarction [heart attacks]."

"Surprisingly, these changes do not seem to have resulted in a fall in the overall incidence of diagnosed CHD, because of the increase in the rate of new angina diagnoses."

However, they suggest that the increase in angina may be due to changes in methods used to diagnose the condition, rather than a real increase in prevalence of the disorder.

Nevertheless, they add: "These results emphasise the ongoing need for treatments and services for coronary heart disease, particularly for new angina or suspected angina. They also highlight the need for continued emphasis on the primary prevention of coronary heart disease."