Epidemiology and Prognostic Implications of Panic Disorder and Generalized Anxiety Disorder in Patients With Coronary Artery Disease

Coronary artery disease (CAD), the most common form of cardiovascular disease, affects approximately 1 in 12 adults in Canada. CAD is a major public health concern and is one of the costliest chronic diseases in North America. Up to 90% of the CAD risk is attributable to nine modifiable risk factors, including psychosocial factors. Decades of research confirmed the importance of psychosocial factors in the development, prognosis and clinical presentation of CAD. One understudied but highly significant psychosocial risk factor is anxiety. Prevalence estimates of anxiety disorders in patients with CAD range from 10% to 65%, with panic disorder (PD) and generalized anxiety disorder (GAD) being the most prevalent. Both PD and GAD have been independently associated with a 36% to 94% increase in the risk of adverse cardiac events in patients with CAD. However, these findings remain controversial as some studies reported either an inverse or no association between PD and adverse events. Still, both PD and GAD are associated with the presence of multiple risk factors for CAD (e.g. smoking, high alcohol consumption and a sedentary lifestyle). These anxiety disorders are also likely to influence medication taking behaviors as well as adherence to cardiac rehabilitation programs. These data highlight the importance and prognostic significance of PD/GAD in patients with CAD. However, considering the contradictory data and significant methodological issues in the available studies, notably in terms of the validity of PD and GAD diagnoses, new, methodologically sound studies are needed to improve our understanding of this clinical problem and improve patient care.

The primary aim of this study is to establish the prevalence and incidence of PD and GAD in the two years following a revascularization procedure for CAD. The secondary aim is to prospectively assess the association between these disorders and cardiac mortality, adverse cardiac events, adherence to recommended treatments (exercise, cardiac rehabilitation, pharmacotherapy),quality of life and psychological distress.

This prospective cohort study will include 3610 patients who will be consecutively recruited following a revascularisation procedure for CAD at the cardiology department of the Quebec Heart and Lung Institute. Patients will be assessed at baseline (within a week of admission) as well as 3, 6, 12 and 24 months later. PD and GAD will be assessed with a standardized and validated semi-structured interview. The presence of adverse events, adherence to treatments, psychological distress and quality of life will be assessed through a review of medical records, questionnaires and interviews.