The research, published in the European Heart Journal, focused on patients with acute coronary syndrome (ACS). ACS is an emergency condition arising from blockage of the coronary arteries, which results in either a myocardial infarction (heart attack) or angina.
The researchers looked at 208 ACS patients admitted to St George’s Hospital, London between June 2007 and October 2008. They assessed the patients’ level of distress and fear of dying and measured levels of a cell-signalling molecule – tumour necrosis factor alpha (TNF alpha) – that is involved in inducing inflammation. The results suggest that ACS patients with intense fear have a four-fold increased risk of suffering large inflammatory responses to a heart attack.
Professor Andrew Steptoe, the first author of the study from University College London (UCL), said:
“We found that, first of all, fear of dying is quite common among patients suffering a heart attack; it was experienced by one in five patients. Although survival rates have improved tremendously over the last few decades, many patients remain quite frightened during the experience. Secondly, fear of dying is not just an emotional response, but is linked into the biological changes that go on during acute cardiac events. Large inflammatory responses are known to be damaging to the heart, and to increase the risk of longer-term cardiac problems such as having another heart attack.”
Professor Steptoe also commented on the subsequent findings, when the patients were followed up three weeks after their initial assessment:
“Fear of dying and inflammatory responses in turn predicted biological changes in the weeks following an acute cardiac event, namely reduced heart rate variability and alterations in the output of the hormone cortisol. These processes may contribute to poor outcomes in the longer term.”
The level of distress was unrelated to any previous experience of having a heart attack, but the research suggested that intense distress might be stimulated by worse or more painful symptoms during ACS.
As well as UCL, the researchers were from the University of Stirling, the University of Bern and St. George’s, University of London. Additional funding came from the Swiss National Foundation.