Exercise and Pharmacotherapy for Anxiety in Cardiac Patients

Coronary heart disease (CHD) is the leading cause of death in the United States; more than 600,000 Americans suffer a fatal cardiac event each year. Traditional CHD risk factors such as high blood pressure, smoking, and elevated cholesterol do not fully account for the timing and occurrence of CHD events and individuals with elevated levels of anxiety appear to have a greater risk of cardiovascular events. The present study will examine the impact of aerobic exercise and Lexapro in the treatment of anxiety and cardiovascular biomarkers among individuals with CHD.

Coronary heart disease (CHD) is the leading cause of death in the United States; more than 600,000 Americans suffer a fatal cardiac event each year. Traditional CHD risk factors such as high blood pressure, smoking, and elevated cholesterol do not fully account for the timing and occurrence of CHD events. The term "cardiovascular vulnerable patient" has been used to describe patients susceptible to acute coronary events based upon plaque, blood, or myocardial characteristics. Psychosocial factors also have been shown to be associated with increased adverse health outcomes and increased cardiovascular vulnerability. For example, clinical depression and elevated depressive symptoms are associated with increased morbidity and mortality, and as a result, the American Heart Association has recommended that clinicians should routinely assess depression in CHD patients. Although much research and clinical recommendations have focused on depression, the significance of anxiety has been largely ignored, despite the fact that anxiety disorders are as prevalent as depression in the general population and are associated with similar levels of disability. Despite the prevalence and prognostic significance of anxiety in CHD populations, there have been few randomized clinical trials (RCTs) specifically targeting anxious CHD patients. Anxiolytic medications, including selective serotonin reuptake inhibitors (SSRIs), have been shown to be effective in treating anxiety. SSRIs have been evaluated for the treatment of clinical depression in cardiac patients, with equivocal results. Surprisingly, to our knowledge, there have been no RCTs examining the efficacy of medications for treating anxiety in CHD patients. Moreover, because many cardiac patients are reluctant to take additional medications and psychotropic medications may not be effective for everyone or may produce unwanted side effects, there continue to be a need to identify alternative approaches for treating anxiety in cardiac patients. The investigators believe that exercise may be one such approach. The purpose of this study is to evaluate the following hypotheses in a population of CHD patients with elevated symptoms of anxiety. The present study will examine the impact of a 3-month intervention of either exercise, Lexapro, or placebo on anxiety symptoms and CHD biomarkers among individuals with cardiac disease and elevated anxiety. The investigators hypothesize that: (1) Both exercise training and medication will reduce anxiety symptoms to a greater extent than placebo; (2) Exercise training will improve CHD biomarkers of risk including autonomic regulation, vascular endothelial function, and inflammation more than either medication or placebo; and (3) Improvements in CHD biomarkers will be mediated by reductions in symptoms of anxiety. The investigators also will explore potential moderators of treatment (e.g., anxiety diagnoses, CHD severity) as well as the longer-term benefits of treatment by documenting medical events and health care costs over a follow-up period of up to 4 years.

Patients will exercise three times per week, under medical supervision, at a level of 70-85% of their VO2peak as determined at the time of their baseline exercise stress test. Patients' exercise will consist of 10 minutes of gradual warm-up exercises followed by 35 minutes of continuous walking, biking, or jogging, and 5 minutes of cool down exercises for a total a 50 minutes per session. Patients will be instructed to monitor their radial pulses and will be checked at least three times per session to ensure that they are within their prescribed exercise training ranges.

Treatment in the medication will be supervised by a study psychiatrist. Drug dispensing will be done by licensed pharmacists at the Duke Investigational Pharmacy Service. The investigators will use the SSRI escitalopram (Lexapro), which has received FDA approval for the treatment of anxiety, in 5 mg capsules. Medication will be dispensed as capsules of escitalopram in individually coded bottles. Medication adherence will be assessed using pill count at each study visit. Patients will visit face-to-face with a study psychiatrist at week 0 (baseline), week 1, week 2, week 4, week 8, and week 12 with phone encounters at weeks 3 and 6. The psychiatrist will make all medication adjustments based primarily upon Spielberger Anxiety Scores. Depending on symptoms, daily escitalopram doses will be titrated to 10 mg after week 2 and to 15 mg or placebo equivalent at week 3 if patients show no change or only minimal improvement.

Treatment in the medication and placebo pill arms will be supervised by a study psychiatrist. Drug dispensing will be done by licensed pharmacists at the Duke Investigational Pharmacy Service, who have extensive experience in clinical trials. Medication will be taken once daily in the morning but can be switched to once daily in the evening if deemed necessary. Placebo medication administration will follow the same protocol as outlined for Lexapro.

The Hospital Anxiety and Depression Scale, Anxiety, is a 7-item subscale with scores ranging from 0-21, with higher scores indicating more anxiety.

To quantify heart rate variability (HRV), an electrocardiogram was recorded for 24-hours using the 3-channel DigiTrak XT Holter recorder (Philips Healthcare, Andover, Massachusetts). Electrocardiographic data were downloaded and edited using the Philips Zymed Holter analysis software (2010 Plus/1810 series) and HRV was estimated from the standard deviation of the normal-to-normal R-R intervals (SDNN).

To assess baroreflex sensitivity (BRS), beat-by-beat systolic blood pressure (SBP) and heart rate (HR) were collected using the Nexfin noninvasive BP monitor (Bmeye, Amsterdam, Netherlands). BRS was estimated from the magnitude of the transfer function relating R-R interval oscillations to SBP oscillations across the 0.07 to 0.1299 Hz, or low frequency band.

Endothelial function, assessed by Flow-Mediated Dilation (FMD), was determined from longitudinal B-mode ultrasound images of the brachial artery. Images were obtained using an Acuson (Mountain View, California) Aspen ultrasound platform with an 11-MHz linear-array transducer after 10 min of supine relaxation and during reactive hyperemia, induced by the inflation of a forearm pneumatic occlusion cuff to suprasystolic pressure (about 200 mm Hg) and subsequent deflation after 5 min. FMD was defined as the maximum percentage change in arterial diameter relative to resting baseline from 10 to 120 s after deflation of the occlusion cuff.

High-sensitivity C-reactive protein was quantified by ELISA (LabCorp). Values >10 mg/L were truncated at 10 to account for acute inflammatory processes that may have skewed the distribution of this blood marker.

Urinary catecholamines, an index of sympathetic nervous system (SNS) activity, served as a biomarker of anxiety. Urinary concentrations of epinephrine (EPI) and norepinephrine (NE) were determined by high-pressure liquid chromatography (HPLC) with electrochemical detection (LabCorp). A composite 24-hr catecholamines z-score is presented. The z-score is the raw score minus the population mean, divided by the population standard deviation. A Z-score of 0 is equal to the mean. Negative numbers indicate values lower than the mean and positive numbers indicate values higher than the mean.

Change in Lipids - Total Cholesterol, LDL (Low-density Lipoprotein), and HDL (High-density Lipoprotein); mg/dL

Inclusion Criteria: Men and women with documented CHD (i.e., a prior MI, coronary revascularization procedure, or >70% stenosis in at least one coronary artery) Age > 39 years Patients also will have an anxiety symptom severity score of at least 8 on the Hospital Anxiety and Depression-Anxiety scale (HADS-A) or a DSM-5 diagnosis of an Anxiety Disorder, such as General Anxiety, Social Anxiety, or Panic Disorder. The study team plans to actively recruit women and minorities, with at least 50% women and 25% minorities. Exclusion Criteria: An MI or coronary revascularization procedure (i.e., CABG or percutaneous coronary intervention) within the last 3 months Unstable angina Severe left ventricular dysfunction (ejection fraction <30%) or decompensated heart failure Unrevascularized left main coronary artery stenosis >50% Complete Pacemaker dependence Resting BP >200/120 mm Hg Conditions that would preclude randomization to either the drug (e.g., prolonged QT interval, known allergy to or intolerance of escitalopram) or exercise (e.g., musculoskeletal problems or abnormal cardiac response to exercise) Patients with a primary psychiatric diagnosis other than Anxiety Disorder will be excluded, including patients with PTSD, OCD, or any of the following DSM-5 diagnoses: Dementia, delirium; Schizophrenia, Schizoaffective, or other psychotic disorder; Psychotic features including any delusions or hallucinations; or Current alcohol or other substance abuse disorder. Similarly, patients who pose an acute suicide or homicide risk or who, during the course of the study, would likely require treatment with additional psychopharmacologic agents will not be enrolled. Patients will also be excluded if they are taking other medications that would preclude assignment to either drug or exercise conditions (e.g., clonidine, dicumarol, anticonvulsants, and MAO inhibitors) or are taking herbal supplements with purported mood effects (e.g., St. John's Wort, valerian, ginkgo). Patients already engaged in regular exercise (at least 30 minutes >1x/week) will not be enrolled. Finally, pregnant women will be excluded from participation.

Blumenthal JA, Smith PJ, Jiang W, Hinderliter A, Watkins LL, Hoffman BM, Kraus WE, Liao L, Davidson J, Sherwood A. Effect of Exercise, Escitalopram, or Placebo on Anxiety in Patients With Coronary Heart Disease: The Understanding the Benefits of Exercise and Escitalopram in Anxious Patients With Coronary Heart Disease (UNWIND) Randomized Clinical Trial. JAMA Psychiatry. 2021 Nov 1;78(11):1270-1278. doi: 10.1001/jamapsychiatry.2021.2236.

Blumenthal JA, Feger BJ, Smith PJ, Watkins LL, Jiang W, Davidson J, Hoffman BM, Ashworth M, Mabe SK, Babyak MA, Kraus WE, Hinderliter A, Sherwood A. Treatment of anxiety in patients with coronary heart disease: Rationale and design of the UNderstanding the benefits of exercise and escitalopram in anxious patients WIth coroNary heart Disease (UNWIND) randomized clinical trial. Am Heart J. 2016 Jun;176:53-62. doi: 10.1016/j.ahj.2016.03.003. Epub 2016 Mar 12.