Patients with heart disease and depression have a significant increase in risk for subsequent acute myocardial infarctions and post-myocardial infarction mortality. Studies have shown an interactive relationship between depression and heart disease. One class of antidepressant medication, the tricyclic anti-depressants, has been shown in some studies to increase the risk for sudden cardiac death in patients with known ischemic heart disease. The newer selective serotonin reuptake inhibitors (SSRIs) have been proved safer in patients with heart disease but may be less effective than tricyclic antidepressants. Nelson and associates studied the efficacy and safety of tricyclic antidepressants versus SSRIs in the treatment of depression in patients with known ischemic heart disease.

The study was a six-week, double-blinded, parallel comparison trial of nortriptyline and paroxetine in the treatment of depression in patients with ischemic heart disease. Adult patients who met the criteria in the Diagnostic and Statistical Manual of Mental Disorders, 3rd ed. rev. (DSM-III-R) for nonpsychotic, unipolar major depression and had a 17-item Hamilton Depression Rating Scale score of 16 or more were considered for the study. The patients also had to have stable, documented ischemic heart disease with no major complications. All the patients had initial psychiatric and cardiac evaluations. There were two treatment groups. The first group received 20 mg of paroxetine per day for three weeks. This dosage was increased to 30 or 40 mg per day if the patient showed no response. The nortriptyline group was started at 25 mg at bedtime and titrated to maintain therapeutic serum levels. Adverse events were recorded by the patient and the investigators. A response to medication was considered positive if the patients improved their Hamilton scores by 50 percent.

Both groups had similar baseline data and cardiac histories. There was no difference in the improvement of the Hamilton Depression Rating Scale scores between the two treatment groups. More patients taking nortriptyline withdrew from the study because of adverse events. The majority of these adverse events were cardiac in nature.

The authors conclude that nortriptyline and paroxetine are effective in treating depression in patients with ischemic heart disease. However, nortriptyline had more adverse events, with the majority of them being cardiac in nature. Paroxetine effectively treats depression in patients with ischemic heart disease and is less likely to cause serious side effects.