According to a Finnish investigation published in the European Heart Journal, individuals who take anti-depressant medications together with anti-psychotic drugs have a significantly higher risk of dying during an acute coronary event of a fatal arrhythmia compared to individuals who do not take these drugs. The study demonstrated that the combination of these drugs was linked with an even more significant risk of sudden cardiac death (SCD) during a coronary event.
Heikki Huikuri, lead researcher of the study from the Institute of Clinical Medicine, University of Oulu (Oulu, Finland), explained:
"We've known for some time that mental disorders increase the risk of cardiovascular mortality, but it hasn't been clearly established if psychiatric disorders, such as depression or schizophrenia, predispose to the occurrence of cardiovascular events or if they increase the patient's vulnerability to suffer fatal outcomes during the event.
For the first time, this study has shown us that it is the increased vulnerability during the even that is the determining factor. It points to an urgent need to improve screening for cardiovascular risk factors in psychiatric patients."
"The study shows, that where possible, the combination of anti-psychotic and anti-depressant medications should be avoided, and that off-label use of psychotropic drugs in the treatment of pain and sleep disorders should be restricted."
The investigation was part of the larger Finnish Genetic Study of Arrhythmic Events (FinGesture), a prospective case-control investigation created in order to compare genetic and other risk profiles of individuals who died from SCD with those who survived acute coronary events.
FinGesture gathered data on 2,732 consecutive individuals who experienced out of hospital SCD from an area in Northern Finland between the years 1998 and 2009. Each case had an autopsy confirmation of SCD during an acute coronary event. The control group consisted of 1,256 individuals who survived acute myocardial infarction (heart attack) who were treated at the University Hospital of Oulu. Data regarding the victim's latest medication was gathered from medico legal autopsy reports as well as questionnaires their relatives answered.
According to the results:
- 9.7% of individuals in the SCD group had taken antipsychotics compared to 2.4% of participants in the control group (OR 4.4. 95% CI 2.9-6.6; P
- 8.6% of individuals in the SCD group had taken this class of medication in comparison to 5.5% of patients in the control group (OR 1.6, 95% CI 1.2-2.2; P=0.003).
After the researchers adjusted for the use of cardiovascular medications, such as aspirin, angiotensin converting enzyme (ACE) inhibitors and beta blocking medication, the examination revealed that differences between the two groups in the use of psychotropic drugs remained considerable.
In the investigation, individuals who died of SCD took both anti-psychotics and tricyclic anti-depressants more frequently, however, the team discovered that excess use of newer anti-depressants and selective serotonin reuptake inhibitors (SSRIs) was not found to be considerable.
"This clearly shows us that the mental disorder itself was not the reason for the association, but rather that it was the drugs used to treat these patients that made sudden cardiac death more probable."
It has been revealed that a few anti-psychotic medications cause prolongation of the QT interval in the electrocardiogram, which can result in torsades de pointes, malignant polymorphic ventricular arrhythmias and eventually SCD. At the cellular level, medications have been connected with inhibition of potassium channels, which is associated with prolongation of the QT interval.
Josep Brugada, from Hospital Clinic of Barcelona, Spain, who was the author of the editorial accompanying the report, said:
"There's a real need to ensure that drug safety studies for new antipsychotic and antidepressant medications are undertaken in conditions of ischemia to reflect the situation found in a myocardial infarction."
In the article, Brugada explains that he believes that individuals who use psychotropic medications represent a high risk population for coronary events due to two factors combined. First, individuals who take psychotropic medications are at an increased risk of experiencing proarrhythmic effects from the drugs taken, and second, they have an increased presence of classical cardiovascular risk factors.
According to Brugada, investigations have demonstrated that these individuals have a higher prevalence of dyslipidaemia and diabetes compared to the general population. In addition they are more likely to lead sedentary lifestyles and have hypertension (high blood pressure).
"I am convinced that it's the combination of these two factors which places this population at greater risk of cardiovascular death than the general population."
Findings such as these highlight the need for psychiatrics and cardiologists to set up reliable links between the two specialties. Brugada said:
"Psychiatrists need to screen their patients routinely for cardiovascular risk factors and, if found to be high, refer to cardiologists. Equally, cardiologists should be alert for psychiatric problems and refer to psychiatrists.
For patients with heart disease, guidelines need to be developed to establish which types of anti-psychotic drugs and anti-depressants should be used in different circumstances."
Written by Grace Rattue