The Psychiatric Management of Patients With Cardiac Disease

Anxiety Among Cardiac Patients

Anxiety is commonly experienced by patients with cardiovascular disease, such as coronary artery disease (CAD) or HF. Following an ACS, 20% to 30% of patients experience elevated levels of anxiety, and 10% to 14% have anxiety levels higher than in the average psychiatric inpatient. While this anxiety gradually improves in the months following ACS, 50% of those patients with elevated anxiety following ACS continue to have elevated anxiety 1 year post-event, suggesting that a significant portion of patients with stable CAD may actually suffer from an anxiety disorder that warrants identification and treatment. Similarly, clinically significant anxiety is present in up to 25% of patients awaiting CABG, though in most cases this anxiety resolves in the three months post-procedure. Anxiety is also highly prevalent in patients with more chronic cardiac diseases, such as HF. In patients with HF, 28% experience clinically significant anxiety, and 13% meet criteria for an anxiety disorder.

Cardiac patients who are subjected to invasive technology, such as implantable cardioverter defibrillators (ICDs) or left ventricular assist devices (LVADs), may also experience anxiety, panic, and fear, oftentimes associated with these devices. A recent systematic review suggests that clinically significant anxiety is present in 27% to 63% of patients pre-implantation and 8% to 59% of patients post-implantation of an ICD. Among patients who have undergone ICD placement, having received a shock from the ICD appears to increase the risk of anxiety, though studies have not universally found this to be true. The prevalence of clinically significant anxiety among patients receiving treatment with LVADs is somewhat lower, with 18% to 23% of patients reporting anxiety symptoms post-LVAD implantation. This anxiety appears to improve as time passes following implantation.

Anxiety Disorders in Cardiac Patients

In addition to high levels of free-floating anxiety, cardiac patients also experience elevated rates of formal anxiety disorders. Similar to the general population, generalized anxiety disorder (GAD) is commonly encountered in patients with cardiovascular disease. Among patients hospitalized for an acute coronary syndrome (ACS, arrhythmia, or HF), GAD was equally prevalent with clinical depression. GAD also affects patients with stable CAD, with prevalence rates ranging from 5% to 24% in this population.

Patients with cardiovascular disease also frequently experience panic disorder (PD), with some studies suggesting that patients with CAD have PD at approximately four times the rate of the general population. Furthermore, approximately 20% of all patients who arrive at Emergency Departments with chest pain meet criteria for PD, and up to 50% of patients who visit outpatient cardiology clinics for evaluation of their chest pain experience panic attacks or meet criteria for PD. While some patients with PD and chest pain may not have underlying structural cardiac disease, some certainly do, and clinicians must remain open to the possibility of co-morbid cardiac illness in this patient population.

Finally, cardiac patients who experience events as traumatic during their hospitalization may exhibit symptoms of post-traumatic stress disorder (PTSD). Recent studies have found that 8% to 16% of patients who have an MI develop symptoms of PTSD; such PTSD symptoms also arise at a similar rate among patients who undergo CABG. Studies of patients receiving intensive care for burn injuries and acute respiratory distress syndrome suggest that PTSD may be even more prevalent among cardiac patients in intensive care units (ICUs). Finally, patients who have undergone placement of AICDs also appear to be at higher risk for PTSD. In this population, 10% to 25% have elevated PTSD symptoms, and approximately 8% likely meet criteria for PTSD. In one study, having more than five shocks from an ICD predicted higher post-traumatic stress symptoms at follow-up.

Association Between Anxiety and Cardiac Illness

Anxiety and anxiety disorders may be associated with an increased risk for cardiovascular disease and poor cardiac outcomes, though the evidence for these relationships is not as strong as that for depression. Epidemiologic studies suggest that cardiac illness may lead to increased anxiety and that anxiety may also exacerbate cardiac illness. Acute and chronic emotional stress have been linked to the development of ventricular arrhythmias and to the exacerbation of silent myocardial ischemia.

Among patients without pre-existing heart disease, anxiety has been associated with the development of CAD. In a recent meta-analysis involving 249,846 healthy individuals, anxious persons were at significantly elevated risk for the development of CAD and for cardiac-related mortality over the next 11 years, independent of health behaviors and sociodemographic and medical covariates. This suggests that among healthy individuals, significantly elevated anxiety may be associated with physiologic changes in the body that predispose to a higher risk for the development and progression of CAD.

Among patients with CAD, the association between anxiety and cardiovascular outcomes is less clear. In a recent meta-analysis of 44 studies and 30,527 individuals, anxiety was associated with an increased risk of poor cardiovascular outcomes in unadjusted analyses; however, when controlling for sociodemographic, medical, and psychological covariates (often depression), many of these relationships became non-significant. This would suggest that much of the relationship between anxiety and outcomes may be explained by other medical and psychiatric variables, such as depression. When examining specific subgroups of patients, anxiety was significantly associated with poor outcomes in patients with stable CAD but not in patients who recently had experienced an ACS. It may be that a certain amount of anxiety is to be expected following ACS, and if this anxiety resolves quickly post-event, it may not have a significant impact on future cardiac health. In contrast, anxiety experienced in the setting of stable CAD may persist for longer periods of time and therefore may have more clinically significant effects on heart health. The links between free-floating anxiety and outcomes is equally unclear in patients with HF. Four recent prospective, observational studies failed to find a significant relationship between anxiety (as a symptom) and mortality, when controlling for relevant medical and psychological covariates. However, similar to the studies in patients with CAD, some of these studies did find trends towards a significant relationship between anxiety and mortality in less-controlled analyses. This suggests that while anxiety may be a useful marker for poor outcomes in patients with HF, its relationship with mortality may be accounted for by other psychiatric, medical, and socio­demographic factors.

While the relationship between anxiety and cardiac outcomes is not entirely clear, there is evidence that specific anxiety disorders are associated with adverse cardiac outcomes. When anxiety reaches the threshold of a disorder, it is by definition more persistent, pervasive, and limiting, and carries a more significant risk in terms of cardiac outcomes. GAD has also been associated with higher rates of smoking, diabetes, and hypercholesterolemia, which may increase the risk of developing cardiovascular diseases. Following MI, GAD has been associated with higher rates of mortality and cardiac re-admissions. Similarly, in patients with stable CAD, GAD diagnosis predicted major cardiac events in the subsequent 2 years.

PD also has been associated with the development and progression of cardiovascular disease. In a study of over 5,000 post-menopausal women, patients with a history of panic attacks in the past 6 months were at higher risk for subsequent MI, cardiac mortality, and all-cause mortality compared to individuals without a history of panic attacks. Similarly, in a systematic review and meta-regression involving over 1 million patients, PD was associated with incident CAD, MI, and major adverse cardiac events. These findings are supplemented by other studies that similarly have found PD to be associated with incident CAD, though one study found that PD diagnosis was associated with a reduced risk of cardiovascular mortality overall.

While there is less research available related to the relationship between PTSD and cardiac health, preliminary evidence suggests that PTSD may be harmful for cardiac health. PTSD has been associated with an increased incidence of CAD, independent of depression and other relevant factors. In patients who have experienced an acute coronary syndrome, PTSD has been linked to a greater risk of major adverse cardiac events and all-cause mortality.

In sum, cardiac patients have high rates of situational anxiety and formal anxiety disorders (e.g., PD, GAD, and PTSD). While the links between anxiety (as a symptom) and cardiovascular outcomes is still unclear, anxiety disorders have been associated with an increased risk of developing cardiac disease, as well as worse cardiac outcomes and increased rates of mortality in patients with established disease. This highlights the importance of accurately identifying and treating these disorders when present in patients at risk for or with existing cardiovascular disease.

Differential Diagnosis of Anxiety in the Cardiac Patient

Anxiety in the general hospital is often a primary psychiatric problem caused by stressful medical events. However, anxiety in the cardiac patient can also be caused by a number of general medical conditions and medications commonly associated with cardiac care ( Table 26-1 ).

Not uncommonly, cardiac events cause anxiety. Myocardial ischemia, arrhythmias, and HF can each cause anxiety owing to the sympathetic discharge associated with these conditions and because of what they may represent to the patient (e.g., the fear of dying, the worsening of medical illness, the loss of role identity). Other general medical conditions may cause or exacerbate anxiety in the cardiac patient; important among these is pulmonary embolism in the sedentary cardiac patient. Anxiety may also be a side effect of medications administered to cardiac patients, such as sympathomimetics. Anxiety can also result from substance intoxication or withdrawal that may be causing or exacerbating acute cardiac issues (e.g., cocaine intoxication, alcohol withdrawal). Finally, impaired sleep in the hospital (as the result of an unfamiliar setting, frequent nursing interventions, and significant noise) can lead to or exacerbate anxiety.

The general hospital psychiatrist should consider general medical causes of anxiety when evaluating cardiac patients; this is especially true when the anxiety has developed during an uneventful hospitalization, when the patient has no history of anxiety, or when anxiety persists despite appropriate treatment.

Psychopharmacologic Issues in the Anxious Cardiac Patient

Agents used to treat anxiety in the general hospital patient include benzodiazepines, antidepressants, and antipsychotics. Benzodiazepines are the medications most frequently used in the treatment of anxiety in cardiac patients. These medications rapidly relieve anxiety and appear to have a number of beneficial cardiovascular effects.

Approach to the Anxious Cardiac Patient

The psychiatric consultant is frequently called to cardiac floors to assess and treat anxiety. A careful, stepwise approach to these consultations can ensure an accurate diagnosis and appropriate treatment.