Hamburg - A patient who receives an implantable cardiac defibrillator (ICDs) after a heart attack is more than twice as likely to die within five years from sheer anxiety over their heart condition, according to a team of German scientists. Even patients who display no severe heart problems after the ICD is implanted have a higher risk of death owing to post-traumatic stress disorder (PTSD) brought on by the trauma of having suffered a heart attack, they said.
Cardiologists often overlook such fears. They tell their patients they have nothing to fear but fear itself. But the patients remain terrified that another heart attack could strike at any time - and that fear increases the chances of another heart event.
The researchers from the Technische University of Munich in Germany found that PTSD symptoms in this patient population were associated with a 2.4-fold increased mortality risk.
"We were struck by the finding that patients suffering from PTSD symptoms had a substantially higher risk of mortality, and it was particularly striking that this association was strengthened after adjustment for known risk factors. This study shows there is direct evidence that PTSD independently influences mortality risk," said principal investigator Dr Karl-Heinz Ladwig.
The study was published in the November 2008 issue of Archives of General Psychiatry.
According to Ladwig, PTSD is often overlooked in cardiac patients. Although it is generally recognized that ICD patients should undergo psychological screening and possible treatment as part of their follow-up care, this does not always translate into clinical practice.
"In part, this may have to do with the patients themselves, many of whom are resistant to this type of care and are intent on coping by themselves, but there is no doubt that they need help," said Ladwig.
The German researchers followed 211 patients with ICDs who routinely attended a cardiac outpatient clinic after a cardiac event in 1998. The study's primary outcome was mortality risk per 1,000 person-years.
Participants were surveyed an average of 27 months after implantation, and at that time 38 reported severe PTSD symptoms and 109 reported low or moderate PTSD symptoms. During an average of 5.1 years, 45 (30.6 per cent) of the patients died: 32 of 109 patients with low or moderate symptoms and 13 of 38 with high levels of symptoms.
In their adjusted analyses, which controlled for age, sex, diabetes mellitus, measures of cardiac disease, comorbid anxiety and depression, the researchers found that PTSD symptoms substantially increased mortality risk.
Despite assurances from cardiologists that they were doing fine, some patients continued to have nagging doubts about their heart. And those patients displayed higher risk of having another heart attack.
"Therefore, the perceived severity rather than the objective severity of a cardiac condition, as determined by cardiac criteria, may be associated with PTSD," the authors write.
According to Ladwig, more research is needed to assess the behavioural and biologic pathways by which PTSD contributes to excess mortality risk in patients with ICDs.
