Effective treatment of depression improves post-myocardial infarction survival

Table 1 Summary of demographic biological, social, and psychological characteristics of depressed post-myocardial infarction patients treated for depression and comparison of those with treatment resistant and non treatment resistant depression (n = 770) n (%)

Characteristics	Treated DepressedPost-MI1	TRDn = 1031	Non TRDn = 6671
Demographics and biological characteristics
Age, mean (SD), yr	59.2 (12.0)	57.0 (11.7)	59.5 (12.0)	t = -2.07, P = 0.04
Gender, female	365 (47.4)	59 (57.3)	306 (45.9)	χ2 (1) = 4.65, P = 0.031
Ethnicity, minority	239 (31.0)	32 (31.1)	207 (31.0)	χ2 (1) = 0.0, P = 0.995
Education:				χ2 (2) = 3.76, P = 0.153
Basic or no HS degree	187 (24.3)	25 (24.3)	162 (24.3)
HS without college degree	419 (54.4)	64 (62.1)	355 (53.2)
Advanced education	146 (19.0)	13 (12.6)	133 (19.9)
Body mass index, mean (SD)	29.2 (6.1)	29.7 (6.3)	29.2 (6.1)	t = 0.77, P = 0.444
Diabetes	264 (34.3)	42 (40.8)	222 (33.3)	χ2 (1) = 2.41, P = 0.120
History of heart failure	101 (13.1)	17 (16.5)	84 (12.6)	χ2 (1) = 1.28, P = 0.258
Hypertension	458 (59.5)	70 (68.0)	388 (58.2)	χ2 (1) = 4.56, P = 0.033
Prior MI	187 (24.3)	22 (21.4)	165 (24.7)	χ2 (1) = 0.41, P = 0.524
Prior stroke	70 (9.1)	13 (12.9)	57 (8.7)	χ2 (1) = 1.80, P = 0.180
Current smoker	254 (33.0)	46 (44.7)	208 (31.2)	χ2 (1) = 7.34, P = 0.007
Social characteristics
Live alone	322 (41.8)	46 (44.7)	276 (41.4)	χ2 (1) = 0.32, P = 0.570
Social support	356 (46.2)	54 (52.4)	302 (45.3)	χ2 (1) = 1.84, P = 0.176
Psychological characteristics
Depression				χ2 (2) = 16.7, P > 0.001
Major depression	398 (51.7)	69 (67.0)	329 (49.3)
Minor depression	348 (45.2)	28 (27.2)	320 (48.0)
Dysthymia	24 (3.1)	6 (5.8)	18 (2.7)
Psychosocial measures
Baseline Depression Symptom Severity (BDI), mean (SD)	17.7 (7.8)	22.4 (9.3)	17.0 (7.4)	t = 6.62, P < 0.001
Baseline Perceived Social Support (ESSI), mean (SD)	24.5 (6.4)	22.9 (7.0)	24.7 (6.3)	t = -2.74, P = 0.006
Baseline Depression Symptom (HAM-D), mean (SD)	17.9 (6.3)	20.9 (6.5)	17.4 (6.1)	t = 5.07, P < 0.001

¹Except where mean (SD) is noted. BDI: Beck Depression Inventory; ESSI: ENRICHD Social Support Inventory; HAM-D: Hamilton Depression Rating Scale; HS: High school; TRD: Treatment resistant depression; MI: Myocardial infarction.

Table 2 Results of separate Cox regression analyses to examine the contributions of each biological, social and psychological predictor to mortality among treated post- myocardial infarction patients with depression (n = 770)

	B	SE	Wald	Sig.	HR	95%CI
Biological factors
Age1	0.048	0.011	19.205	< 0.001	1.05	1.027-1.073
Female gender	0.741	0.266	7.791	0.005	2.098	1.247-3.531
Minority status	0.020	0.272	0.005	0.943	1.020	0.599-1.737
Diabetes	1.448	0.272	28.401	< 0.001	4.255	2.498-7.247
Heart failure	1.495	0.275	29.507	< 0.001	4.461	2.601-7.652
Hypertension	1.002	0.322	9.675	0.002	2.723	1.449-5.120
Prior MI	0.961	0.261	13.533	< 0.001	2.616	1.567-4.365
Prior stroke	1.165	0.306	14.496	< 0.001	3.207	1.760-5.843
Current smoker	-1.128	0.361	9.781	0.002	0.324	0.160-0.656
Social factors
Live alone	0.552	0.258	4.591	0.032	1.737	1.048-2.880
Perceived social support	-0.046	0.028	2.768	0.096	0.955	0.904-1.008
Social isolation	-0.197	0.258	0.582	0.446	0.822	0.496-1.361
Psychological factor
Baseline depression symptom severity	< 0.001	0.016	0.001	0.978	1.000	0.968-1.032
Treatment resistant depression	0.534	0.312	2.927	0.087	1.705	0.925-3.143

¹Age centered on the lowest age of 34 years. For dichotomous variables reference group is the absence of the named predictor. MI: Myocardial infarction.

Table 3 Final model: Results of Cox regression analysis to examine the independent contributions of biological, social, and psychological predictors and treatment resistant depression to all cause mortality among post-myocardial infarction patients treated for depression (n = 770)

	B	SE	Wald	Sig.	HR	95%CI
Biological factors
Age1	0.035	0.012	8.280	0.004	1.036	1.011-1.061
Diabetes	1.069	0.294	13.243	0.000	2.912	1.638-5.180
Heart failure	1.007	0.290	12.089	0.001	2.736	1.551-4.827
Current smoker	-0.690	0.403	2.932	0.087	0.502	0.228-1.105
Social factors
None
Psychological factor
Treatment resistant depression	0.691	0.347	3.967	0.046	1.995	1.011-3.938

¹Age centered on the lowest age of 34 years. For dichotomous variables, reference group is the absence of the named predictor.