Inactivity Promotes Postsurgical Depression in Cardiac Patients

A new study suggests that physical inactivity following cardiac surgery is linked to a substantially higher risk of depression.

Researchers at the University of Manitoba (Winnipeg, Canada) reviewed 436 patients awaiting non-emergent cardiac surgery who completed the Patient Health Questionnaire-9 (PHQ-9) to quantify depression. Physical activity was assessed with the International Physical Activity Questionnaire (IPAQ-short) and accelerometry. The researcher collected data preoperatively (Q1), at hospital discharge (Q2), at 3 months (Q3), and at 6 months (Q4) after surgery. Patients were categorized as "depression naive,” "at risk", or "depressed" preoperatively, and physical inactivity was defined as less than 600 metabolic equivalent min/week.

Depression prevalence from Q1-Q4 was 23%, 37%, 21%, and 23%, respectively. Independent associations with depression were preoperative left ventricular ejection fraction less than 50%, physical inactivity, baseline "at-risk", and baseline "depressed" groups, hospital stay of over a week, postoperative stressful event, and cardiopulmonary bypass time higher than 120 minutes. Newly depressed patients 6 months postoperatively reported lower IPAQ-short physical activity than depression-free patients did (median change: -40 min/week compared to +213 min/week). The study was published in the December 2013 issue of the Canadian Journal of Cardiology.

“Depression in the patient undergoing cardiac surgery appears complex,” concluded lead author Rakesh Arora, MD, PhD, and colleagues of department of surgery. “Preoperative physical inactivity independently poses a two-fold risk for depression before surgery and is associated with the development of new depression postoperatively.”

The reverse is also true. Studies have shown that major depressive disorder is an independent risk factor for the development of coronary artery disease (CAD) and increases the risk of cardiac events and premature death. Prevalence estimates of depression among patients with CAD requiring cardiac surgery ranges from 23%–47%. Approximately half of patients suffering from depression before cardiac surgery remain depressed one year after surgery, and an additional 20% of patients who undergo CABG experience depressive symptoms after surgery.

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University of Manitoba