Examining the relation between post myocardial infarction depression and cardiovascular prognosis using a validated prediction model for post myocardial mortality

Abstract

Background: The presence of depressive symptoms after myocardial infarction (MI) is associated with worsened cardiovascular (CV) prognosis. To date, it remains unclear to what extent the relationship between post-MI depression and prognosis is confounded by factors related to prognosis. We assessed the relationship between depression and prognosis while adjusting for a well validated risk score for mortality after a MI.

Methods: Data of 494 MI patients were derived from the Depression after Myocardial Infarction study (DepreMI). Scores on the Beck Depression Inventory (BDI) (cut-off ≥ 10) were used to relate depressive symptoms (divided in somatic/affective and cognitive/affective symptoms) to the Global Registry of Acute Coronary Events (GRACE) risk score, using Pearson correlations. Cox regression analysis was performed to investigate the predictive value of depressive symptoms for prognosis after adjusting for GRACE score.

Results: Overall, depressive symptoms were significantly correlated with GRACE score (r=0.12, p=0.008). Specifically, somatic/affective symptoms were positively correlated (r=0.23, p<0.001), whereas cognitive/affective symptoms tended to be negatively correlated (r=-0.08, p=0.097) with GRACE score. Adjusting for GRACE score did not affect the HR for recurrent CV events associated with total BDI- score (adjusted hazard ratio (HR) per point increase in BDI score 1.05 p=0.002 95% CI 1.02-1.08 n=463). Furthermore GRACE score attenuated the HR associated with 1 SD increase in somatic/affective depressive symptoms from 1.44 (1.20-1.72) to 1.31 (1.08-1.58).

Conclusion: GRACE score was positively associated with somatic/affective depressive symptoms. GRACE score explained only partly the association between (somatic/affective) depressive symptoms and CV prognosis.

Keywords: Depression; Myocardial infarction; Prognosis.