One in eight people who suffer a heart attack or other life-threatening cardiac event go on to suffer post-traumatic stress disorder (PTSD), according to an analysis of multiple studies.  Furthermore, those patients who develop PTSD appear to have twice the risk of suffering another heart attack or dying within one to three years, compared to patients who didn’t develop PTSD.

PTSD is an anxiety disorder that typically follows exposure to a traumatic event such as combat, disaster or assault.  Symptoms include nightmares, avoidance of reminders of the event and elevated heart and blood pressure.

“The underlying similarity between heart attacks, combat experiences, even witnessing other people going through violence is that the individual perceives his or her own life is in danger,” Edmondson explained.  “The person experiences the threat of mortality and feels out of control.”

The analysis, which was published in the journal PLoS One, looked at 24 separate studies involving more than 2,300 people worldwide and found approximately 12 percent of people develop clinically significant symptoms of PTSD, while 4 percent meet full diagnostic criteria for the disorder.

Given that approximately 1.4 million people in the U.S. suffer an acute cardiac event per year, this would indicate 168,000 patients will develop clinically significant PTSD symptoms as a result – and most will go unrecognized, according to the study’s lead author Dr. Donald Edmondson, assistant professor of behavioral medicine at Columbia University Medical Center.

“There have been studies that have looked at this before, but most of those used very small samples [of people],” Edmondson explained.  “When we ask what the prevalence is in 2,300 patients, that’s when people sit up and take notice.  There’s an issue here – this is something we need to pay attention to.”

In addition, Edmondson said, three of the studies in the analysis, comprised of 600 patients total, revealed that heart attack patients with PTSD had double the risk of suffering another heart attack or dying within a few years.

“It’s not just a quality of life issue, but a quantity of life issue – that’s also something that makes the medical community take notice,” he said.

Patient mortality

While there are no proven explanations as to why PTSD may increase likelihood of death among heart patients, Edmondson said researchers do have a couple hypotheses.  One is based on the physiological response associated with PTSD, which increases activity of the automatic nervous system and leads to inflammation in the body.

“Inflammation in the system is central to heart disease,” Edmondson explained.  “It leads to clogging of the arteries.”

Another hypothesis focuses on the behavioral responses of patients with PTSD.  Studies done in patients who have suffered strokes and other life-threatening medical issues show that PTSD may be associated with poor adherence to taking secondary prevention medications.

“What may be happening is the patients are avoiding reminders of traumatic events,” Edmondson said.  “While the medications in reality are there to help, psychologically they may function as a reminder of the initial heart attack, so patients avoid that by skipping the medications or forgetting to take them.”

According to Edmondson, there are two main factors that predict which patients will go on to develop PTSD.  The first is ‘paratraumatic cognition,’ or the subjective experience of the patient during the heart attack.

“In heart attack patients, the objective severity of the heart attack, whether it’s a really terrible one versus one that has a great survival rate, does not predict later PTSD symptoms,” Edmondson sad.  “It’s really about the subjective experience of the patient.”

For example, he explained, a patient with a lot of chest pain during a heart attack may be more likely to develop PTSD than a patient with less chest pain, because the patient with less chest pain has less perception of a lack of control.

The second factor that appears to influence the likelihood of developing PTSD is the age of the patient.  Younger heart attack patients are much more likely to develop the anxiety disorder than older patients, Edmondson said.

“People who are younger perceive heart attacks as being more ‘off time’ because their friends haven’t had them,” he said.  “A 45-year-old who has a heart attack is confronted with his or her mortality in a way that most are not, and it can be really psychologically disruptive.”

Treating PTSD in heart patients

For heart patients with PTSD, an empirical study done in the past year has shown that one of the most popular PTSD treatments – talk therapy – appears to be safe and effective.

“I have three classes of takeaways,” Edmondson said, “For the patient, if you’re having intrusive recollections of trauma or having nightmares or you feel keyed up, you’re not strange.  This is not some weird thing – it’s something we understand, it’s treatable.

“For family members, social support is the big key.  Just because it’s over for family members, and the patient is out of physical danger, it doesn’t mean it’s over psychologically.  Be on the lookout for things like sleep disturbance.”

And finally, for cardiologists, Edmondson said awareness was crucial.  “Cardiologists have been on the cutting edge of behavioral medicine for a long time,” he said.  “We learned years ago people get depressed after heart attacks and now, every cardiologist will list off depression as a risk factor after heart attacks. So they’re open to this information; they just haven’t had it before.”

“We got burnt in the academic community on screening everyone for things like prostate cancer or breast cancer, so I don’t recommend screening everyone because it’s possible that you can overtreat sometimes, but awareness is more warranted.”