A world first study has shed fresh light on why people traumatised by the loss of a loved one are more susceptible to having a heart attack.

The study conducted by clinicians from the Sydney Medical School and the Faculty of Nursing and Midwifery at the university, provides new insight into why people going through the emotional stress caused by bereavement are more at risk of heart disease.

The reasons for this risk have not been well understood to date although acute stress is increasingly linked to heart attack.

Funded by the North Shore Heart Research Foundation and National Heart Foundation, the study involved 80 bereaved adults and is the most comprehensive of its type ever undertaken in Australia or internationally.

Results from the study, called 'Cardiovascular Risk in Bereavement' (CARBER), were recently published in the respected Internal Medicine Journal and presented at the Australia and New Zealand Annual Cardiac Society Conference in Sydney.

The bereaved responded positively to participating in the study, due in large part to the efforts of the multidisciplinary research team. The team included social work, pastoral care, critical care and research nursing, psychology, psychiatry, hypertension, haematology and cardiology.

Dr Thomas Buckley, lead author of the study and Senior Lecturer from the Faculty of Nursing and Midwifery, said the main reason the link between bereavement and heart attacks has not been well understood is that until now there has not been a comprehensive study done in the first weeks following bereavement.

CARBER is the first study to look in detail at people during the first weeks immediately following their loss, said Dr Buckley, revealing that across all age groups and both sexes, emotional and mood changes were greatest during this time.

Overall the bereaved who participated in CARBER had increases in anxiety, depression and anger symptoms, together with elevated stress hormones and reduced sleep and appetite, said Dr Buckley.

They also showed increases in blood pressure and heart rate, together with immune and blood clotting changes - all changes that could contribute towards a heart attack, he said. An improvement was seen at six months, although several measures were still at a higher level than seen in a non-bereaved comparison group.

Professor Geoffrey Tofler, a cardiologist the Sydney Medical School and Royal North Shore Hospital and senior study investigator, says that at a time when the focus is naturally on the deceased person, this study shows the importance of maintaining the health of bereaved family members.

The results of CARBER provide clues for preventive measures which we plan to investigate, said Professor Tofler. With 34 per cent of deaths in Australia currently due to cardiovascular disease, making headway towards reducing heart disease remains very important. he added .

Professor Tofler said by monitoring the behavioural, mood and physiological changes of people going through the trauma of a major loss, the study authors had been able to indentify which of these changes may put a person more at risk of heart disease.

Although it would be too simplistic to suggest that the study proves why people can die of a broken heart, the insights offered by CARBER take us into new territory in trying to understand the link between acute emotional stress and heart attack, Professor Tofler said.

The research team included Associate Professor Roger Bartrop, who has previously conducted groundbreaking research into immune function in bereavement, along with Dr Anastasia Susie Mihailidou, Dr Marie-Christine Morel-Kopp, Associate Professor Christopher Ward and Emeritus Professor Christopher Tennant from the Sydney Medical School; Professor Sharon McKinley from the Faculty of Nursing, Midwifery and Health at the University of Technology, Sydney; and Ms Monica Spinaze, Ms Margaret Bramwell, Ms Dianne Roche, Ms Angela Tannard, Ms Belinda Hocking, Ms Kerrie Goldston and Mr Walter Chen.