Date Published: February 28, 2019
Publisher: Public Library of Science
Author(s): D. Scott Kehler, Andrew N. Stammers, David Horne, Brett Hiebert, George Kaoukis, Todd A. Duhamel, Rakesh C. Arora, Chris Harnish.
To determine the independent and combined impact of preoperative physical activity and depressive symptoms with hospital length of stay (HLOS), and postoperative re-hospitalization and mortality in cardiac surgery patients.
A cohort study including 405 elective and in-house urgent cardiac surgery patients were analyzed preoperatively. Physical activity was assessed with the International Physical Activity Questionnaire to categorize patients as active and inactive. The Patient Health Questionnaire-9 was used to evaluate preoperative depressive symptoms and categorize patients as depressed and not depressed. Patients were separated into four groups: 1) Not depressed/active (n = 209), 2) Depressed/active (n = 48), 3) Not depressed/inactive (n = 101), and 4) Depressed/inactive (n = 47). Administrative data captured re-hospitalization and mortality data, and were combined into a composite endpoint. Models adjusted for demographics, comorbidities, and cardiac surgery type. Multiple imputation was used to impute missing values.
Preoperative physical activity behavior and depression were not associated with HLOS examined in isolation or when analyzed by the physical activity/depressive symptom groups. Physical inactivity (HR: 1.60, 95% CI 1.05 to 2.42; p = 0.03), but not depressive symptoms, was independently associated with the composite outcome. Freedom from the composite outcome were 76.1%, 87.5%, 68.0%, and 61.7% in the Not depressed/active, Depressed/active, Not depressed/inactive, and Depressed/inactive groups, respectively (P = 0.02). The Active/Depressed group had a lower risk of the composite outcome (HR: 0.35 95% CI 0.14 to 0.89; p = 0.03) compared to the other physical activity/depression groups.
Preoperative physical activity appears to be more important than depressive symptoms on short-term postoperative re-hospitalization and mortality.
Cardiac surgery seeks to improve cardiac symptoms, quality of life and long-term survival in patients with significant coronary artery and valvular disease. However, non-traditional risk factors, such as elevated depressive symptoms, are highly prevalent in the cardiac surgery population, which could negatively impact their health outcomes peri-operatively despite a technically successful procedure . Contemporary studies estimate that 20–38% of cardiac surgery patients are depressed in the peri-operative setting which is considerably higher than the general population and in patients with coronary artery disease not requiring surgical intervention [2–5]. Preoperative depression and depressive symptoms appear to be independent risk factors for poor outcomes, such as mortality, hospital readmissions, recurrent cardiac events, and poor health-related quality of life [3, 6, 7], which may persist in the postoperative period even though the surgical procedure was uneventful . In response to these important investigations and based on the recommendations from the American Heart Association , there is an increased interest in implementing routine depression screening in clinical practice in an attempt to identify depressed cardiac surgery patients preoperatively, although data to support this recommendation are limited .
This study was a post-hoc analysis from a prospective observational study of 436 consecutively consenting patients undergoing elective or in-house urgent cardiac surgery in Canada [4, 5]. The study was supported by an unrestricted operating grant from Pfizer Canada. This organization was not involved in the study design, collection of data, or analysis and interpretation of the study findings, nor had the right to approve or disprove the manuscript. The study protocol was approved by the University of Manitoba Human Research Ethics Board, the St. Boniface Hospital Research Review Committee, and the Manitoba Health Information Privacy Committee.
The purpose of this study was to determine the individual and combined impact of preoperative physical activity and depressive symptoms on operative HLOS and one-year postoperative re-hospitalization and mortality in cardiac surgery patients. Neither depressive symptoms nor physical activity were associated with HLOS when examined individually. Patients defined as Not depressed/Active prior to cardiac surgery had a shorter HLOS compared to those who were Depressed/Inactive. Preoperative physical activity, but not depressive symptoms, were independently associated with a lower risk of the composite endpoint of re-hospitalization/mortality. Examined in combination, the Depressed/Active group were more likely to have event-free survival one-year postoperatively, compared to the Depressed/Inactive group. Collectively, these data suggest that preoperative physical activity is an important indicator of perioperative health outcomes, and may have its greatest health benefits in those with elevated depressive symptoms post-cardiac surgery.
This study provides novel insights into the impact of preoperative physical activity behavior on the postoperative health outcomes or cardiac surgery patients. A more physically active lifestyle prior to cardiac surgery may have its most beneficial effects in patients with elevated depressive symptoms. As such, the findings from this study suggest that preoperative physical activity behavior should be considered in the evaluation of short-term health outcomes among patients undergoing a cardiac surgical intervention.