Background: Depression and anxiety are highly prevalent and co-morbid in acute coronary syndrome patients.
Somatic and cognitive subtypes of depression and anxiety in acute coronary syndrome have been shown to be
associated with mortality although their association with patient outcomes is unknown, as are the mechanisms
that underpin these associations. We are conducting a prospective cohort study which aims to examine in acute
coronary syndrome patients: (1) the role of somatic subtypes of depression and anxiety as predictors of health
related quality of life outcomes; (2) how somatic subtypes of depression and anxiety relate to long term vocational
functioning and healthcare utilisation; and (3) the role of the autonomic nervous system assessed by heart rate
variability as a moderator of these associations.
Methods: Patients are being screened after index admission for acute coronary syndrome at a single, high volume
centre, MonashHeart, Monash Health, Victoria, Australia. The inclusion criterion is all patients aged > 21 years old
and fluent in English admitted to MonashHeart, Monash Health with a diagnosis of acute coronary syndrome. The
primary outcome is mean health related quality of life (Short Form-36) Physical and Mental Health Summary scores
at 12 and 24 months in subtypes with somatic symptoms of depression and anxiety. Depressive domains are
assessed by the Beck Depression Inventory II and the Cardiac Depression Scale. Anxiety is measured using the
Speilberger State-Trait Anxiety Inventory and the Crown Crisp Phobic Anxiety questionnaire. Secondary outcomes
include clinical variables, healthcare service utilisation and vocational functioning.
Discussion: This manuscript presents the protocol for a prospective cohort study which will investigate the role of
somatic subtypes of depression and anxiety as predictors of health related quality of life, long-term vocational
functioning and health service use, and the role of the autonomic nervous system in moderating these associations.
Findings from the study have the potential to inform more effective pharmacological, psychological and behavioural
interventions and better guide health policy on the use of health care resources.