Carol Percival

New onset depression following myocardial infarction predicts cardiac mortality.

Objective: Studies investigating the effects of depression on mortality following myocardial infarction (MI) have produced heterogeneous findings. We report on a study investigating whether the timing of the onset of depression, with regard to the MI, affected its impact on subsequent cardiac mortality. Methods: Five hundred and eighty-eight subjects admitted following MI underwent assessments of cardiac status, cardiac risk factors, and noncardiac illness. We identified separately subjects who were depressed before their MI (pre-MI depression) and those who developed depression in the 12 months after MI (new-onset depression), using a standardized questionnaire and a research interview. Patients dying of cardiac cause were identified during 8-year follow-up using information from death certificates. Results: Multivariate predictors of cardiac death during follow-up included: greater age (hazards ratio (HR) = 1.06, p = .007), previous angina (HR = 4.15, p < .0005), high Killip Class (HR = 2.21, p = .013), prescription of beta-blockers on discharge (HR = 0.37, p = .02), and new-onset depression (HR = 2.33, p = .038). Pre-MI depression did not convey any additional risk of cardiac mortality. Conclusion: We have shown increased cardiac mortality in patients who develop depression after suffering MI. Further observational studies need to separate pre- and post-MI depression if we are to determine underlying mechanisms by which depression is associated with mortality following MI. MI = myocardial infarction; CPK = creatine phosphokinase; ECG = electrocardiogram; WHO = World Health Organization; HADS = Hospital Anxiety and Depression Scale; ICD-10 = 10th version of the International Classification of Diseases; SCAN = schedule for assessment in neuropsychiatry; ACE Inhibitors = angiotensin converting enzyme inhibitors; CABG = coronary artery bypass graft; SD = standard deviation.

Lack of a close confidant, but not depression, predicts further cardiac events after myocardial infarction

Objective: To assess the role of depression and lack of social support before myocardial infarction (MI) in determining outcome in a large representative sample of patients admitted after MI in the UK. Design: Prospective cohort design. Patients: 1034 consecutive patients were screened 3–4 days after MI. Main outcome measures: Mortality and further cardiac events over one year after an MI. Results: At 12 months’ follow up mortality and further cardiac events were assessed in 583 of 654 eligible patients (90% response); 140 of 589 for whom baseline data were collected (23.8%) were depressed before their MI. Patients who were depressed before their MI were not more likely to die (mortality 5.2% v 5.0% of non-depressed patients) or suffer further cardiac events (cardiac events rate 20.7% v 20.3% of non-depressed patients). After controlling for demographic factors and severity of MI, the absence of a close confidant predicted further cardiac events (hazard ratio 0.57, p  =  0.022). Conclusion: Lack of a close confidant but not depression before MI was associated with adverse outcome after MI in this sample. This association may be mediated by unhealthy behaviours and lack of compliance with medical recommendations, but it is also compatible with difficulties in early life leading to heart disease.

The relationship between vital exhaustion, depression and comorbid illnesses in patients following first myocardial infarction

OBJECTIVE Vital exhaustion and depression are both independent risk factors for cardiovascular disease, yet the relationship between these highly similar dimensions remains unclear. We have examined the association between depression and vital exhaustion and investigated the extent to which any association is the result of comorbid illnesses. METHODS Three hundred and five consecutive patients were examined on average 3.6 days following hospital admission with first myocardial infarction (MI). The Maastricht Questionnaire (MQ; vital exhaustion) was administered together with the Hospital Anxiety and Depression Scale (HADS), and details of comorbid physical illness were recorded. The factor structure of the MQ was explored using factor analysis. RESULTS Depression and vital exhaustion were highly correlated (r=.61, P<.01). This correlation did not diminish on controlling for age, sex, and comorbidity (r=.59, P<.01). Factor analysis of MQ score gave a four-factor solution: fatigue (18.2% of variance), depression (17.9%), lack of concentration (9.5%), and sleep difficulties (8.1%). The fatigue dimension of the MQ remained highly associated with HADS depression score (r=.50, P<.01), controlling for age, sex, and comorbidity. CONCLUSIONS Depression and fatigue are highly correlated and their association is not attributable to comorbid physical illnesses or the tendency of the MQ to measure depression. Future studies should investigate fatigue instead of vital exhaustion as a potential risk factor for poor cardiac prognosis independent of the influence of depression.

The risk factors for depression in first myocardial infarction patients

BACKGROUND Depression affects outcome following myocardial infarction but the risk factors for such depression have been little studied. This study considered whether the causes of depression occurring before and after myocardial infarction were similar to those of depression in the general population. METHOD Consecutive patients admitted to hospital following their first myocardial infarction were interviewed with the Schedule for Clinical Assessment in Neuropsychiatry to detect psychiatric disorders and the Life Events and Difficulties Schedule to assess recent stress. Participants completed the Hospital Anxiety and Depression Scale (HADS) at entry to the study and 1 year later and the risk factors associated with a high score at both times were assessed. RESULTS Of 314 (88% of eligible) patients who were recruited, 199 (63%) were male and 63 (20%) had depressive disorders. Logistic regression identified the following as independently associated with depressive disorder that had been present for at least I month before the myocardial infarction: younger age, female sex, past psychiatric history, social isolation, having marked non-health difficulties and lack of a close confidant. At follow-up 269/298 (90%) responded; of 189 participants not depressed at first assessment, 39 (21%) became depressed by the 1 year follow-up. Logistic regression identified frequent angina as the only significant predictor of raised HADS scores at 12 months. CONCLUSIONS Depression developing during the year following myocardial infarction does not have the same risk factors as that which precedes myocardial infarction. Further clarification of the mechanisms linking depression to poor outcome may require separation consideration of pre- and post-myocardial infarction depression, and its risk factors.

Negative illness perceptions are associated with new-onset depression following myocardial infarction

OBJECTIVE To test the hypothesis that negative perceptions about heart disease at the time of the myocardial infarction (MI) were associated with the onset of new episodes of depression following MI. METHOD We recruited 269 subjects admitted following first MI and monitored their depression status over the subsequent 12 months. At baseline, we recorded demographic information, family and personal history of cardiac disease and severity of MI; subjective health beliefs were assessed using the Illness Perceptions Questionnaire (IPQ). We assessed depression at baseline, 6 and 12 months following MI using a standardised questionnaire, validated in this population against a semistructured research interview. RESULTS In the days following MI, patients who subsequently developed depression were more likely to anticipate that their heart disease would last a long time (P=.012) and was unlikely to be cured (P=.038). Controlling for potential confounding variables, scores on the IPQ remained associated with subsequent depression (P = .036), with anticipation that heart disease would last a long time [odds ratio (OR)=2.7, P=.013] and that heart disease could be cured (OR=0.45, P=.048) showing strongest association. CONCLUSIONS Negative perceptions about heart disease in the days following admission to hospital with first MI are associated with the development of subsequent new episodes of depression.