Depression is a well-known risk factor for recurrent cardiac events (RCEs) but findings are less consistent for anxiety, not previously reported on using a time-dependent approach. We aimed to study the prognostic effect of anxiety and depression symptom levels on RCEs.

Data (N = 595) were drawn from the UPBEAT-UK heart disease patient cohort with 6-monthly follow-ups over 3 years. Hospital Anxiety and Depression Scale symptoms were grouped into: agitation (three items), anxiety (four items), and depression (seven items) subscales. We performed two types of multivariate analyses using Cox proportional hazard models with delayed entry: with baseline variables (long-term analysis), and with variables measured 12-to-18 months prior to the event (short-term time-dependent analysis), as RCE risk factors.

In the baseline analysis, both anxiety and depression, but not agitation, were separate RCE risk factors, with a moderating effect when considered jointly. In the short-term time-dependent analysis, elevated scores on the anxiety subscale were associated with increased RCE risk even when adjusted for depression [hazard ratio (95% confidence interval) 1.22 (1.05–1.41), p = 0.009]. Depression was no longer a significant predictor when adjusted for anxiety [1.05 (0.87–1.27), p = 0.61]. For anxiety, individual items associated with RCEs differed between the two approaches: item 5 ‘worrying thoughts’ was the most significant long-term risk factor [1.52 (1.21–1.91), p = 0.0004] whereas item 13 ‘feelings of panic’ was the most significant time-dependent short-term risk factor [1.52 (1.18–1.95), p = 0.001].

Anxiety is an important short-term preventable and potentially causal risk factor for RCEs, to be targeted in secondary cardiac disease prevention programmes.

Evidence suggests that somatic rather than cognitive depressive symptoms are risk factors for recurrent cardiac events in at-risk patients. However, this has never been explored using a time-dependent approach in a narrow time-frame, allowing a cardiac event-free time-window.

The analysis was performed on 595 participants [70.6% male, median age 72 (27–98)] drawn from the UPBEAT-UK heart disease patient cohort with 6-monthly follow-ups over 3 years. Depressive symptomatology was measured using the Patient Health Questionnaire-9 (PHQ-9) (four somatic, five cognitive items). New cardiac events (NCEs) including cardiac-related mortality were identified by expert examination of patient records. Analyses were performed using Cox proportional hazard models with delayed entry, with time-dependent depressive dimensions and covariates measured 12–18 months (median: 14.1, IQR: 3.5) prior to the event, with a 12-month cardiac event-free gap.

There were 95 NCEs during the follow-up [median time-to-event from baseline: 22.3 months (IQR: 13.4)]. Both the somatic (HR 1.12, 95% CI 1.05–1.20, p = 0.001) and cognitive dimensions (HR 1.11, 95% CI 1.03–1.18, p = 0.004) were time-dependent risk factors for an NCE in the multi-adjusted models. Specific symptoms (poor appetite/overeating for the somatic dimension, hopelessness and feeling like a failure for the cognitive dimension) were also significantly associated.

This is the first study of the association between depressive symptom dimensions and NCEs in at-risk patients using a time-to-event standardised approach. Both dimensions considered apart were independent predictors of an NCE, along with specific items, suggesting regular assessments and tailored interventions targeting specific depressive symptoms may help to prevent NCEs in at-risk populations.