Specificity of depression following an acute coronary syndrome to an adverse outcome extends over five years

Many studies have demonstrated that depression is associated with a worse cardiovascular outcome and increased risk of death in those experiencing an acute coronary syndrome (ACS). Recent studies have suggested, however, that any association is strongly influenced by the timing of the depression, with post-ACS depression providing the greatest risk. Establishing any timing impact should assist etiological clarification. We initially recruited 489 subjects hospitalized for an ACS, assessed lifetime and current depression, and then – at 1 and 12 months – assessed subsequent depression. Subjects were followed for up to 5 years to assess cardiovascular outcome and the impact of depression at differing time points, with three defined poor outcome categories (i.e. cardiac admission and/or cardiac rehospitalization). While outcome was associated with a number of non-depression variables, a poor outcome was most clearly associated with depressive episodes emerging at the time of the ACS but with some risk affected by episodes that commenced prior to the ACS and being persistent. Neither lifetime depressive episodes nor transient depressive episodes occurring around the baseline ACS event appeared to provide any risk. Study findings indicate that any differential deleterious impact of post-ACS depression has both short-term and longer-term outcomes, and, by implicating the centrality of post-ACS depression, should assist studies seeking to identify causal explanations.