The significance of depression in older patients after myocardial infarction

Depression is common in patients recovering from a myocardial infarction (MI) and is an independent risk factor for early mortality. Although most patients with MI are aged 65 and older, there is little information about post-MI depression in this age group. This study was performed to determine the significance of post-MI depression in individuals aged 65 and older.

A cohort study of hospitalized patients and a telephone interview 4 months later.

A university-affiliated teaching hospital in Baltimore, Maryland.

Patients admitted with an acute MI (N = 284), 153 (53.9%) of whom were aged 65 and older; 101 of these (66.0%) completed the 4-month follow-up interview.

Patients were interviewed 3 to 5 days post-MI to evaluate for the presence of symptoms of depression (a score of > or =10 on the Beck Depression Inventory and for the presence of mood disorder using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Revised, Third Edition. Survivors were then interviewed by telephone 4 months after discharge to assess adherence to recommendations to reduce cardiac risk by using the Medical Outcomes Study Specific Adherence Scale. Comorbidities and prescribed medications were determined by review of hospital charts and computerized medical records.

Older patients with depression were more likely to die in the first 4 months than older patients without depression (26.5% vs 7.3%, P =.002). Older patients with depression were also more likely than older patients without depression to have had a prior MI (54.3% vs 31.0%, P =.012) and were somewhat more likely to have chronic lung disease (28.6% vs 14.4%, P =.054), a non-Q wave MI (88.6% vs 72.8%, P =.054), diabetes mellitus (48.6% vs 32.5%, P =.082), and a left ventricular ejection fraction below 35% (50.0% vs 33.3%, P =.084). Compared with older patients without depression, depressed older patients were also marginally less likely at discharge to be prescribed a beta-blocker (74.3% vs 86.3%, P =.092) or a lipid-lowering agent (31.4% vs 49.6%, P =.059). Depressed patients aged 65 and older were less likely to adhere to a low-fat/low-cholesterol diet (P <.01) or a diabetic diet (P <.01), or to be taking prescribed medications (P <.05), exercising regularly (P <.01), reducing stress (P <.01), and increasing social support (P <.01).

Depression is prevalent after an acute MI in patients aged 65 and older. Older post-MI patients with depression have more comorbidities than older patients without depression and have almost four times the risk of dying within the first 4 months after discharge. Although this increased risk is likely to be related to many factors, our data suggest that sicker patients who are older and depressed may less often be prescribed medications known to reduce post-MI mortality and may also have greater difficulty following recommendations to reduce cardiac risk than their counterparts without depression. Efforts to improve adherence to post-MI treatment guidelines and to enhance patient compliance may improve prognosis in this high-risk group.