The study looked at people aged 20-64 years who had depression.
Depression is a common and debilitating condition. From 1988-1994 to 2005-2008, the use of antidepressants in the US almost quadrupled, and by 2005-2008, antidepressants were the third most frequently prescribed drug in the country.
Globally, cardiovascular diseases are a major cause of death and disability.
People with depression tend to be more susceptible to cardiovascular problems. There has been speculation that antidepressants, and selective serotonin reuptake inhibitors (SSRIs) in particular, contribute to this, as they may affect coagulation. However, this has not been confirmed.
In 2011, the US Food and Drug Administration (FDA) and the European Medicines Association warned that doses of Citalopram, one of the most common antidepressants, should not exceed 40 mg per day, after studies indicated the presence of heart rhythm disorders in participants taking a range of doses.
Study involved 238,963 participants
Researchers from the University of Nottingham in the UK investigated the relationship between different antidepressant drugs and rates of three cardiovascular issues in people with depression.
They analyzed data for 238,963 patients aged 20-64 years, with a first diagnosis of depression between 2000-2011.
The scientists looked at tricyclic antidepressants, SSRIs and other types of antidepressant, as well as the dosage and duration of use.
They also adjusted for age, gender, alcohol and tobacco use, other conditions and use of other drugs.
Fluoxetine appears to decrease risk
In a 5-year period, 772 patients had a myocardial infarction, 1,106 had a stroke or transient ischemic attack, and 1,452 experienced arrhythmia.
However, there was no evidence that SSRIs increase the risk of arrhythmia, heart attacks and stroke or transient ischemic attacks. In fact, in the first year of follow-up, SSRIs were associated with a significantly lower risk of myocardial infarction, compared with no use of antidepressants.
However, during the first 4 weeks of use, tricyclic and related antidepressants appeared to double the risk of arrhythmia.
Author Carol Coupland, who is a professor of Medical Statistics in Primary Care at Nottingham University, says:
"We found some indication that selective serotonin reuptake inhibitors were associated with a reduced risk of heart attacks, particularly with the use of fluoxetine. Absolute risks of heart attacks were six per 10,000 for selective serotonin reuptake inhibitors over 1 year, and four per 10,000 for fluoxetine compared with 10 per 10,000 for non-use."
Citalopram was the most commonly prescribed drug in the study. Findings did not suggest an increased risk of arrhythmia, even at higher doses.
However, since only 18% of the Citalopram prescriptions in the study were for high doses, the authors note that higher doses could pose a risk, and they recommend avoiding them, especially for patients who are already more likely to develop cardiovascular problems.
The researchers note that the results do not prove a causative link, but they describe them as "reassuring in the light of recent safety concerns."
Limitations include the fact that data were not available for all confounders, for example, information about diet and exercise.
Earlier this year, Medical News Today reported on research that suggested taking antidepressants during pregnancy does not increase the risk of congenital heart defects.