DEPRESSION AND 18-MONTH PROGNOSIS AFTER MYOCARDIAL-INFARCTION

Background We previously reported that major depression in patients in the hospital after a myocardial infarction (MI) substantially increas es the risk of mortality during the first 6 months. We examined the im pact of depression over 18 months and present additional evidence conc erning potential mechanisms linking depression and mortality. Methods and Results Two-hundred twenty-two patients responded to a modified ve rsion of the National Institute of Mental Health Diagnostic Interview Schedule (DIS) for a major depressive episode at approximately 7 days after MI. The Beck Depression Inventory (BDI), which measures depressi ve symptomatology, was also completed by 218 of the patients. All pati ents and/or families were contacted at 18 months to determine survival status. Thirty-five patients met the modified DIS criteria for major in-hospital depression after the MI. Sixty-eight had BDI scores greate r than or equal to 10, indicative of mild to moderate symptoms of depr ession. There were 21 deaths during the follow-up period, including 19 from cardiac causes. Seven of these deaths occurred among patients wh o met DIS criteria for depression, and 12 occurred among patients with elevated BDI scores. Multiple logistic regression analyses showed tha t both the DIS (odds ratio, 3.64; 95% confidence interval [CI], 1.32 t o 10.05; P=.012) and elevated BDI scores (odds ratio, 7.82; 95% CI, 2. 42 to 25.26; P=.0002) were significantly related to 18-month cardiac m ortality. After we controlled for the other significant multivariate p redictors of mortality in the data set (previous MI, Killip class, pre mature ventricular contractions [PVCs] of greater than or equal to 10 per hour), the impact of the BDI score remained significant (adjusted odds ratio, 6.64; 95% CI, 1.76 to 25.09; P=.0026). In addition, the in teraction of PVCs and BDI score marginally improved the model (P=.094) . The interaction showed that deaths were concentrated among depressed patients with PVCs of greater than or equal to 10 per hour (odds rati o, 29.1; 95% CI, 6.97 to 122.07; P<.00001). Conclusions Depression whi le in the hospital after an MI is a significant predictor of 18-month post-MI cardiac mortality. Depression also significantly improves a ri sk-stratification model based on traditional post-MI risks, including previous MI, Killip class, and PVCs. Furthermore, the risk associated with depression is greatest among patients with greater than or equal to 10 PVCs per hour, This result is compatible with the literature sug gesting an arrhythmic mechanism as the link between psychological fact ors and sudden cardiac death and underscores the importance of develop ing screening and treatment programs for post-MI depression.