Link between heart disease and PTSD
PTSD (post-traumatic stress disorder) has been linked to cardiovascular disease but the reason why was unclear.
Dr. Viola Vaccarino, professor of epidemiology, has been trying to unlock this mystery by studying war veteran twins over a long period of time. “Studying twins allowed us to separate factors that are often associated with both PTSD and heart disease but do not causally link the two disorders, including genetic, environmental, and behavioral factors that run in families and are shared among twins,” says Vaccarino.
Vaccarino and her team looked at examinations of 275 twin participants that were 12 years apart. Both exams included a clinical assessment of PTSD and heart imaging scans of myocardial perfusion with Positron emission tomography, which show how well blood flows through the heart muscle.
This technique allowed the researchers to assess myocardial flow reserve, which is a measure of the health of the small coronary vessels that bring blood within the heart muscle, known as the coronary microcirculation. Unlike obstructive coronary artery disease that affects large coronary vessels, dysfunction of the coronary microcirculation is caused by excessive tightening or malfunction of these small blood vessels rather than blockage by atherosclerotic plaque.
Among the study’s key findings are:
- PTSD is associated with dysfunction of the coronary microcirculation rather than accumulation of coronary atherosclerotic plaques. This was also noted over time, showing deterioration of the heart’s microcirculation and reduced blood flow between the two visits.
- The connection between PTSD and ischemic heart disease was particularly noted amongst twins with longstanding PTSD, which suggests that the long duration of the condition plays a role.
- The connection was noted even when comparing twin brothers who differed in PTSD diagnoses. This ruled out influences from environmental, behavioral, or genetic factors that are shared by brothers and that may be precursors of both PTSD and heart disease.
These data fill a significant gap in evidence concerning the long-term consequences of PTSD on the heart. Understanding the connection between the two should help in long-term efforts for risk prediction, prevention, and treatment to reduce the burden of ischemic heart disease among individuals with PTSD.
