Cardiovascular and antidepressant effects of imipramine in the treatment of secondary depression in patients with ischemic heart disease

Direct and indirect effects of psychopharmacological treatment on the cardiovascular system

Background Severe mental disorders, i.e. psychotic disorders, unipolar and bipolar disorders are associated with increased morbidity and mortality from cardiovascular and metabolic disorders. The underlying cause of this association is complex and comprises disorder specific alterations such as dysfunctions of immunological and hormonal systems, body-composition changes and health associated behaviors (smoking, sedentary lifestyle, alcohol intake and treatment compliance). Furthermore, some psychopharmacological drugs may exert unwanted side effects that impact the cardiovascular system. Methods This paper reviews studies concerning commonly used antidepressant and antipsychotics drugs with a particular focus on direct and indirect cardiovascular side effects. Results Newer antidepressant drugs have a favorable cardiovascular safety profile compared to tricyclic antidepressants. However, QTc prolongation, increased blood pressure and potentially higher risks of bleeding have been observed in some newer antidepressants. Some second generation (atypical) antipsychotics have raised concern because of indirect cardiovascular, metabolic side effects such as weight gain and disturbances in lipid and glucose metabolism. Conclusions Psychiatrists need to be aware of potential direct and indirect cardiovascular side effects and to include them in the risk/benefit assessment when choosing a specific individualized treatment.

Treatment of affective disorders in cardiac disease

Patients with cardiovascular disease (CVD) commonly have syndromal major depression, and depression has been associated with an increased risk of morbidity and mortality. Prevalence of depression is between 17% and 47% in CVD patients. Pharmacologic and psychotherapeutic interventions have long been studied, and in general are safe and somewhat efficacious in decreasing depressive symptoms in patients with CVD. The impact on cardiac outcomes remains unclear. The evidence from randomized controlled clinical trials indicates that antidepressants, especially selective serotonin uptake inhibitors, are overwhelmingly safe, and likely to be effective in the treatment of depression in patients with CVD. This review describes the prevalence of depression in patients with CVD, the physiological links between depression and CVD, the treatment options for affective disorders, and the clinical trials that demonstrate efficacy and safety of antidepressant medications and psychotherapy in this patient population. Great progress has been made in understanding potential mediators between major depressive disorder and CVD—both health behaviors and shared biological risks such as inflammation.

Treatment of depression in cardiovascular disease

BACKGROUND AND OBJECTIVES

Depression in patients with Cardiovascular Disease (CVD) is extremely common, with a prevalence of 17-47%, and is associated with increased risk of morbidity and mortality. Treatment of depression has been hypothesized to reduce cardiac mortality. Pharmacologic and psychotherapeutic interventions have been studied and appear to be safe and in some studies effective in reducing depressive symptoms in patients with cardiac disease. The impact on cardiac outcomes remains unclear. This review briefly focuses on the prevalence of depression in patients with CVD, the physiological links between depression and CVD, and largely is concerned with the clinical trials that seek to demonstrate efficacy and safety of antidepressant medications and psychotherapy in this patient population.

METHODS

PubMed and PsycINFO databases were searched through July 2012. Publications were included if they were in English, a review article, or a clinical trial in the CVD population with comorbid depression. The search was completed with key words of antidepressants, CVD, coronary artery syndrome, SSRIs, depression, treatment of depression, post-MI (where MI is myocardial infarction), major depression, and cardiac disease. Trials were included if the patients were above the age of 18, both male and female genders, and had cardiac comorbidity. No trials were excluded.

RESULTS

A total of 61 articles and/or book chapters were included. The majority were from North America and Europe. There were 7 clinical trials of tricyclic antidepressants (TCAs), one of TCAs and bupropion, and 10 trials of selective serotonin reuptake inhibitors (SSRIs). We also evaluated five trials involving psychotherapeutic techniques and/or collaborative care.

CONCLUSIONS

There is considerable evidence from randomized controlled clinical trials that antidepressants, especially SSRIs, are safe in the treatment of major depression in patients with CVD. Although efficacy has been demonstrated in some, but not all, trials for both antidepressants and certain psychotherapies, large, well-powered trials are urgently needed. There are virtually no data available on predictors of antidepressant response in depressed patients with CVD. Whether successful treatment of depression is associated with a reduction in cardiac morbidity and mortality remains unknown.

Impact and clinical management of depression in patients with coronary artery disease

The rates of major adverse coronary events, including recurrent ischemic events and death, in patients with coronary artery disease (CAD) have been shown to be significantly increased in patients with depression. In addition, health care costs are higher and health-related quality of life is lower in depressed patients with CAD. Several pathophysiologic mechanisms have been proposed for the association of increased events seen in this population. Studies have focused on antidepressants (specifically, selective serotonin reuptake inhibitors and mirtazapine), psychotherapy (cognitive behavioral therapy and interpersonal psychotherapy), and a wide range of other nonpharmacologic interventions. Pharmacologic and nonpharmacologic treatments are known to improve depressive symptoms in patients with CAD, but their effects on outcomes such as mortality and hospital admissions remain controversial. If treatment of depression is warranted, strategies should include sertraline or citalopram, with or without cognitive behavioral therapy, based on the known efficacy and safety of the drugs in this population. Nonpharmacologic therapy such as aerobic exercise has been shown to improve not only depression but also cardiovascular health. When selecting an appropriate antidepressant, clinicians should consider their patients' comorbid conditions and the potential for drug interactions, and treatment should be frequently monitored. Screening for depression in patients with cardiac disease should be instituted on a routine basis by using either case-finding or symptom-triggered approaches. Based on the high prevalence of depression and its known adverse effects in patients with CAD, future research is needed to help determine the role of antidepressants and nonpharmacologic strategies in improving outcomes in patients with both comorbidities.

Safety of antidepressant drugs in the patient with cardiac disease: a review of the literature

Patients with cardiac disease, specifically ischemic heart disease and heart failure, have a higher frequency of major depressive disorder than patients without cardiac disease. The pathophysiologic reason for this is not completely understood. Previous depression, other debilitating illnesses, and type A personality are risk factors for the development of depression in cardiac patients. Depression has been shown to lower the threshold for ventricular arrhythmias. Therefore, treatment of depression potentially may prolong life in these patients. Antidepressant options that have been evaluated include several of the tricyclic antidepressants, trazodone, bupropion, and several of the selective serotonin reuptake inhibitors. Individual antidepressant drugs vary in their pharmacologic activity and side-effect profiles. Although clinical data are limited, it is important to individualize therapy in order to minimize cardiac adverse effects. Clinicians are encouraged to evaluate patients with cardiac disease for major depressive disorder and to consider antidepressant drug therapy for these patients when appropriate.

Management of Depression in Patients with Comorbid Cardiovascular Disease

Evidence suggests that depression commonly occurs in patients with cardiovascular disease and is associated with a poor prognosis including increased risk of cardiac mortality. Proposed pathophysiologic mechanisms include decreased heart rate variability, altered sympathetic and parasympathetic activity, increased ventricular instability, and abnormal platelet reactivity. Other proposed mechanisms involve the interference of depression with medication adherence and cardiac risk factor reduction. Despite this evidence, depression during cardiovascular disease is commonly unrecognized and inadequately treated. Tricyclic antidepressants (TCA) are efficacious for treating depression in this population but cause serious cardiac side effects and should be avoided in patients with significant cardiovascular disease. More recent studies with bupropion and the selective serotonin reuptake inhibitors (fluoxetine, paroxetine, sertraline) indicate that they are acceptable alternatives to TCAs with regard to cardiac risk in depressed patients with heart disease, although larger studies are needed to validate their safety and efficacy in this special population. There are 3 studies currently being conducted to investigate the effect of antidepressant therapy and/or psychotherapy on cardiac morbidity and mortality in post–myocardial infarction patients with depression and/or low social support. These studies will hopefully answer the long-posed question of whether appropriate treatment of depression can improve cardiac prognosis.

Protection of neuronal uptake-1 inhibitors in ischemic and anoxic hearts by norepinephrine-dependent and -independent mechanisms

Cardiac ischemia and anoxia induce massive norepinephrine (NE) release, which is mediated by a reverse operation of uptake-1 and can be suppressed by uptake-1 inhibitors. We studied effects of uptake-1 inhibitors on incidence of ventricular fibrillation (VF%) and myocardial contracture in perfused rat hearts under ischemic or anoxic conditions. NE release occurred in hearts during ischemia or anoxia and was largely inhibited by desipramine, imipramine, and cocaine. The generation of inositol 1,4,5-trisphosphate (InsP3) during reperfusion also was abolished by desipramine. During anoxia/reoxygenation, VF (93 and 71%, respectively) and myocardial contracture occurred and were significantly inhibited by desipramine and by NE depletion. Regional ischemia and reperfusion induced high VF% (86 and 100%, respectively), which was reduced or abolished by desipramine and imipramine at 0.03 and 0.3 microM. During the ischemic phase, cocaine was similarly antiarrhythmic, as was a combination of timolol and prazosin, but NE depletion was not. In NE-depleted hearts, cocaine or the combination of timolol and prazosin showed limited effect on VF%, whereas both desipramine and imipramine abolished VF. In anesthetized rats in vivo, ischemic VF% was reduced by desipramine (30 vs. 92%; p < 0.01). In conclusion, uptake-1 inhibitors protect hearts against ischemia/reperfusion- and anoxia/reoxygenation-induced arrhythmias, partly because of the inhibition of locally mediated NE release. Other actions of desipramine and imipramine may contribute to the overall efficacy.

Suppression of ventricular arrhythmias resulting from acute coronary artery ligation in rat by imipramine

The potential antiarrhythmic activity of imipramine against ventricular arrhythmias induced by coronary artery ligation in rats has been investigated and compared with procainamide. Imipramide (1 and 5 mg/kg-1) or procainamide (5 and 10 mg/kg-1) or solvent were injected intravenously 30 min before ligation. Imipramine reduced the total number of ventricular ectopic beats as well as the incidence and duration of ventricular tachycardia and ventricular fibrillation. The drug did not significantly affect the blood pressure but reduced the heart rate. The antiarrhythmic activity of imipramine is postulated to be due to a quinidine-like effect and/or alpha-adrenergic blocking activity. The study confirms the potential utility of imipramine as an antiarrhythmic drug.

Antidepressants: a clinical update for medical practitioners

Knowledge of the pharmacologic actions of antidepressants enables the physician to develop an appropriate rationale for the use of these medications in the medical setting. The appropriate choice of drug and adequate dose, duration, maintenance, termination, therapy, and alternatives should be considered.