Individuals who receive implantable cardiac defibrillators after a sudden heart event appear more likely to die within five years if they experience symptoms of post-traumatic stress disorder, regardless of the severity of their disease, according to a report in the November issue of Archives of General Psychiatry.
Surviving a life-threatening heart condition, such as heart attack or cardiac arrest, causes significant distress, according to background information in the article. Resulting symptoms—including intense fear, painful intrusive memories and hyperarousal (a state of physical and psychological tension resulting from the flight-or-fight response)—may qualify an individual for a diagnosis of post-traumatic stress disorder (PTSD). Between 8 percent and 20 percent of patients with acute coronary syndromes and 27 percent to 38 percent of those who survive a cardiac arrest develop PTSD.
Karl-Heinz Ladwig, Ph.D., M.D., of Technische Universitaet Muenchen, Munich, and Helmholtz Zentrum National Research Center for Environmental Health, Neuherberg, Germany, and colleagues studied 211 patients who had received implantable cardiac defibrillators (devices that administer shocks to help restore normal heartbeat) following a heart event in 1998. Participants were surveyed an average of 27 months after implantation and 38 reported severe PTSD symptoms. All patients were then tracked through medical records, telephone interviews, reports from family members and death certificates through March 2005.
During the average follow-up period of five years, 45 of the patients (30.6 percent) died. This included 32 of the 109 patients with low or moderate PTSD symptoms and 13 of 38 patients with high levels of such symptoms. "Our findings provide direct evidence for an independent influence of PTSD symptoms on fatal outcome in these patients," the authors write. "Experiencing PTSD symptoms conferred a 2.4-fold long-term age- and sex-adjusted mortality [death] risk for patients with implantable cardiac defibrillators."
Patients with PTSD in the study reported more cardiac symptoms, such as chest pain, than those without PTSD. However, clinical characteristics that typically account for survival differences in such patients—for example, the frequency at which their defibrillator administers shocks—did not differ between the two groups. "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.
"Further investigations are required to assess the behavioral and biologic pathways by which posttraumatic maladaptation contributes to the excess mortality risk in patients with implantable cardiac defibrillators," they continue. One possible explanation is that medical recommendations for cardiac care—including drug prescriptions—may act as "traumatic reminders" for patients with PTSD and may therefore be ignored or avoided.
"The findings underline the urgent need for routinely applied comprehensive and interdisciplinary psychosocial aftercare for patients with implantable cardiac defibrillators," the authors conclude. "Although the serious mortality risk of PTSD in patients with implantable cardiac defibrillators needs to be further investigated before firm recommendations can be made, screening for PTSD symptoms in patients with implantable cardiac defibrillators is likely to be clinically beneficial, and treatment in selected patients should be attempted."