Heart disease, which has been declining for 30 years, appears to be back on the rise mainly among the young, experts have said.

The long-term trend is flattening or going into reverse among those now in their late thirties to early fifties with potentially disastrous consequences, according to several studies in Britain and the US.

Obesity and diabetes are pushing up rates of the disease, suggesting that complacency over progress in cutting heart deaths has been premature.

The trend “may represent the leading edge of a growing storm”, said Simon Capewell, Professor of Clinical Epidemiology at the University of Liverpool and an expert on heart disease statistics.

Last week the Department of Health issued a report congratulating itself on having met, five years early, the target to cut heart deaths in people under 75 by 40 per cent.

However, evidence is now emerging that this trend, which began long before current drugs and treatments were available, may be reversing. In the US, the UK and Australia, the evidence is that while death rates continue to fall among the old, they are levelling off or rising among men and women aged 35 to 54 who have ignored warnings about junk food, smoking and excessive drinking. In 2002, said Professor Capewell, heart disease mortality in the UK increased among men aged 35-44 for the first time in more than two decades, despite the improvements in care. “The party is over and complacency runs a high risk” he said. “The flattening trends in mortality rates among young adults suggest that the cardiovascular disease epidemic is not being controlled.”

The most recent data, published this month in Archives of Internal Medicine by a team from the University of British Columbia and the Mayo Clinic, come from postmortem examinations of more than 425 people who lived in one county in the US state of Minnesota, and who died of unnatural causes – accidents, homicides, or suicides – between 1981 and 2004. None of the deaths was from heart disease, but the postmortems assessed the state of the bodies’ coronary arteries. Over the whole period, 83 per cent had some evidence of coronary artery disease, and 8.2 per cent had high-grade disease.

The proportion with high-grade disease, likely to lead to heart disease and death had they lived, had declined over time. But this decline “ended after 1995 and possibly reversed after 2000”.

The implications of increasing rates of heart disease are alarming, according to an editorial in the same issue of the journal. It calls for younger people to be monitored for early signs of heart disease with much greater vigilance.

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