Did an MI depress them or were they always that way?

Heart attack patients often get depressed.
Sertraline helps them but only if they were depressed before

By Owen Dyer

A positive attitude can go a long way when recovering from a heart attack. The flip side of the coin is that depression can be fatal to heart attack patients.

About 20% of people who have recently suffered a heart attack meet the criteria for major depression, and these patients report dramatically worse quality of life and functionality even when treadmill scores suggest they are physically no worse off than other heart attack patients.

Worse, multiple studies have shown that depression in acute coronary syndrome and after heart attack roughly triples mortality in the months and years after the acute event, with the degree of risk being correlated with the severity of depression. Yet no one has previously investigated the effect of antidepressant therapy on depressed cardiac patients.

The Sertraline Antidepressant Heart Attack Randomised Trial (SADHART) study sought to test the efficacy of the common antidepressant sertraline (the generic name for Zoloft) in patients recently admitted to hospital for either myocardial infarction or unstable angina pectoris who met standard diagnostic criteria for major depression. The study involved 369 patients and was conducted in 40 outpatient cardiology centres and psychiatry clinics in seven countries, including Canada.

The first analysis of this trial was published in the Journal of the American Medical Association in August 2002. More out of hope than expectation, the investigators looked for improvement in left ventricular ejection fraction among depressed patients given sertraline. They found none. Among the secondary outcomes, however, there was evidence that depressed cardiac patients given sertraline had a somewhat lower rate of adverse cardiac events over the six-month study period. Moreover, they scored significantly better on the Clinical Global Impression Improvement Scale (CGI-1), a standard psychiatric test.

Quality of life
A second SADHART analysis has now been published in the American Journal of Cardiology, which concentrates purely on psychiatric well-being and quality-of-life indicators. All of the patients studied met Diagnostic and Statistical Manual for Mental Disorders (DSM-IV) criteria for major depressive disorder and had a Beck Depression Inventory score greater than 10. These psychiatric criteria are somewhat less stringent than those typically found in antidepressant trials, which normally recruit severely depressed patients. Most of the patients in this study suffered from mild to moderate depression. About one-third had a previous history of recurrent depression and more severe depression scores. This subgroup was analysed separately as well as being included in the overall analysis.

Despite their moderate depression scores, most patients in the study reported severe impairment in quality of life. In fact, this research corroborated recent studies that suggested that depression in cardiac patients is a clearer prognostic indicator of poor quality of life than physical indices of cardiovascular function.

The patients were tested on three depression scales: the patient-rated Beck Depression Inventory, the Hamilton Rating Scale for Depression (HAM-D), and the CGI-I. They were also measured using the short form of the patient-rated Quality of Life Enjoyment and Satisfaction scale (Q-LES-Q), and the Medical Outcomes Study Short-Form 36 item (SF-36), which rates functional status.

Most patients' depression scores improved quite dramatically over the 24-week period analysed. The placebo group, however, showed almost as much improvement as those on sertraline. For the overall group, only the investigator-rated CGI-I scale showed a significant extra benefit in the sertraline group. Among the recurrent depression subgroup, however, the antidepressant showed significant benefit on all three depression scales.

Regarding patient functionality, the SF-36 scale suggested that sertraline brought significant improvement in mental and physical scores among both the recurrently depressed patients and the overall group. But the improvement was much more significant for the recurrent depression subgroup. On the Q-LES-Q quality-of-life index, sertraline brought significant benefit to the recurrently depressed patients but not to the overall group. Based on these results, the authors recommended sertraline for depressed cardiac patients who have previously suffered depression when they are physically healthy, but not for those whose depression is clearly due to their heart attack. Could it be that people who are depressed because of illness are less amenable to pharmacological intervention?