Influence of comorbid heart disease on dyspnea and health status in patients with COPD – a cohort study

Figures & data

Figure 1 Flow chart patient selection.

Notes: HD = COPD patients with a heart disease diagnosis at baseline. New HD = COPD patients with heart disease diagnosed between 2003 and 2012. No HD = COPD patients without heart disease.
Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; HD, heart disease.

Table 1 Patient characteristics in 2005 by HD group in 2012

Baseline characteristics, 2005	All patients, n (%)	No HD, n (%)	New HD, n (%)	P-value	HD, n (%)	P-value
Number of patients	495	334 (67)	58 (12)		103 (21)
Sex				0.17		<0.001
Male	207 (42)	118 (35)	26 (45)		63 (61)
Female	288 (58)	216 (65)	32 (55)		40 (39)
Age groups (years)				0.002		<0.001
≤60	143 (35)	118 (35)	7 (12)		18 (18)
61–70	160 (48)	160 (48)	39 (67)		54 (52)
>70	56 (17)	56 (17)	12 (21)		31 (30)
Level of education (n=488)				0.73		0.02
Low	322 (66)	207 (63)	38 (66)		77 (75)
High	166 (34)	121 (37)	20 (34)		25 (25)
Level of care				0.41		<0.001
Hospital care	90 (18)	44 (13)	10 (17)		36 (35)
Primary care	405 (82)	290 (87)	48 (82)		67 (65)
Current daily smoking				0.01		0.22
No	363 (73)	232 (70)	53 (91)		78 (76)
Yes	132 (27)	102 (30)	5 (9)		25 (24)
FEV1%pred (n=216)				0.47		0.79
≥80	54 (21)	38 (23)	4 (15)		12 (20)
50–79	132 (52)	89 (53)	13 (50)		30 (51)
<50	67 (27)	41 (24)	9 (35)		17 (29)
BMI (kg/m^2; n=480)				0.21		0.25
Underweight (<20)	40 (8)	29 (9)	2 (3)		9 (9)
Normal weight (≥20, <25)	168 (35)	116 (36)	25 (44)		27 (27)
Overweight (≥25, ≤30)	173 (36)	118 (37)	16 (28)		39 (39)
Obesity (>30)	99 (21)	59 (18)	14 (25)		26 (26)
Depression	57 (12)	42 (13)	7 (12)	0.91	8 (8)	0.18
Diabetes	50 (10)	29 (9)	7 (12)	0.41	14 (14)	0.14
Hypertension	124 (25)	78 (23)	16 (28)	0.49	30 (29)	0.24
Exacerbation in the previous 6 months				0.84		0.88
No exacerbation	310 (65)	208 (65)	37 (64)		65 (64)
≥1 exacerbation	166 (35)	111 (35)	21 (36)		101 (36)

Notes: No HD = COPD patients without heart disease; new HD = patients diagnosed with heart disease between 2003 and 2012; HD = COPD patients with heart disease at baseline. P-values with no HD as reference. Exacerbation was defined as an unplanned health care visit or course of oral steroids.

Abbreviation: BMI, body mass index.

Figure 2 Number of COPD patients in the whole study group with comorbid heart disease in 2003 and 2012.

Notes: HD = COPD patients with heart disease at baseline. New HD = patients diagnosed with heart disease between 2003 and 2012. No HD = COPD patients without heart disease.

Table 2 Symptoms and health status 2005 and 2012

	All patients, n (%)	No HD, n (%)	New HD, n (%)	P-value	HD, n (%)	P-value
mMRC 2005a
0	53 (11)	39 (12)	5 (9)	Ref	9 (9)	Ref
1	168 (36)	124 (38)	17 (29)	0.10	28 (29)	0.96
2	83 (18)	54 (17)	12 (21)	0.34	17 (17)	0.50
3	79 (17)	46 (15)	10 (18)	0.37	23 (24)	0.09
4	85 (18)	51 (16)	13 (23)	0.23	21 (21)	0.20
Mean mMRC 2005 (SD)	2.0 (1.3)	1.8 (1.3)	2.2 (1.3)	0.06	2.2 (1.3)	0.02
mMRC 2012a
0	54 (12)	40 (13)	4 (7)	Ref	10 (10)	Ref
1	137 (29)	100 (32)	16 (29)	0.43	21 (22)	0.68
2	74 (16)	52 (16)	10 (18)	0.30	12 (12)	0.87
3	78 (16)	53 (17)	4 (7)	0.70	21 (21)	0.29
4	125 (27)	69 (22)	22 (39)	0.05	34 (35)	0.10
Mean mMRC 2012 (SD)	2.2 (1.4)	2.0 (1.4)	2.4 (1.4)	0.05	2.5 (1.4)	0.005
Mean CCQ (SD) 2005b	2.1 (1.3)	1.9 (1.2)	2.3 (1.5)	0.08	2.4 (1.1)	0.002
Symptoms	2.2 (1.3)	2.1 (1.2)	2.4 (1.4)	0.23	2.5 (1.2)	0.001
Functional state	2.2 (1.9)	1.6 (1.3)	2.2 (1.7)	0.01	2.2 (1.3)	0.002
Mental state	1.8 (1.4)	2.1 (1.8)	2.3 (1.8)	0.58	2.2 (1.7)	0.20
Mean CCQ (SD) 2012b	2.2 (1.4)	2.1 (1.3)	2.6 (1.7)	0.04	2.5 (1.2)	0.02
Symptoms	2.4 (1.4)	2.3 (1.3)	2.6 (1.6)	0.10	2.7 (1.1)	0.01
Functional state	2.1 (1.6)	1.9 (1.6)	2.6 (1.9)	0.01	2.2 (1.2)	0.01
Mental state	2.1 (1.6)	2.1 (1.7)	2.3 (2.0)	0.39	2.3 (1.7)	0.38
CAT 2012b	17 (9.0)	15.9 (9.1)	19.1 (9.2)	0.04	19.9 (7.6)	0.002

Notes: mMRC, CCQ and CAT scores in 2005 and 2012 for the different groups of COPD patients with and without heart disease. No HD = COPD patients without heart disease. New HD = COPD patients diagnosed with heart disease between 2003 and 2012. HD = COPD patients with heart disease at baseline. P-values with no HD as reference.

a n=468,

b n=346.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire.

Table 3 Regression analyses with CCQ, CAT and mMRC ≥2 in 2012 as dependent variables

	Regression coefficient (95% CI)	P-value	Regression coefficient (95% CI), adjusted for confounders	P-value	Regression coefficient (95% CI), adjusted for confounders and baseline CCQ	P-value
No HD	Ref	Ref	Ref	Ref	Ref	Ref
Linear regression CCQ total
New HD	0.12 (0.04–0.90)	0.03	0.12 (0.05–0.88)	0.03	0.06 (−0.11–0.56)	0.19
HD	0.12 (0.05–0.82)	0.03	0.09 (−0.05–0.71)	0.09	0.02 (−0.24–0.37)	0.67
Linear regression CCQ symptoms
New HD	0.09 (−0.06–0.80)	0.09	0.09 (−0.07–0.76)	0.10	0.05 (−0.13–0.55)	0.23
HD	0.11 (0.01–0.769)	0.04	0.06 (−0.16–0.60)	0.45	0.00 (−0.33–0.30)	0.94
Linear regression CCQ functional state
New HD	0.14 (0.17–1.20)	0.009	0.14 (0.18–1.16)	0.01	0.06 (−0.11–0.72)	0.15
HD	0.14 (0.13–1.03)	0.01	0.12 (0.04–0.92)	0.03	0.05 (−0.19–0.58)	0.32
Linear regression CAT
New HD	0.17 (0.30–6.00)	0.03	0.12 (0.04–5.91)	0.03	0.06 (−0.68–3.85)	0.17
HD	0.17 (1.44–6.43)	0.002	0.15 (0.89–5.92)	0.01	0.07 (−0.40–3.76)	0.11
Logistic regression mMRC ≥2
	OR (95% CI)	P-value	OR (95% CI), adjusted for confounders	P-value	OR (95% CI), adjusted for confounders and baseline mMRC	P-value
New HD	1.45 (0.80–2.61)	0.22	1.37 (0.74–2.53)	0.32	0.99 (0.49–1.99)	0.99
HD	1.74 (1.08–2.81)	0.02	1.71 (1.03–2.86)	0.04	1.44 (0.81–2.56)	0.21

Notes: Results from linear regression analyses with CCQ and CAT as dependent variables. The data are presented as regression coefficients (±95% CI). Beside sex, only associated variables in univariate regression were included in the adjusted regression analysis: sex, age, educational level, exacerbations in the previous 6 months in 2005 and heart disease. Results from logistic regression analyses with mMRC ≥2 as a dependent variable. The data are represented as OR (±95% CI). Beside sex, only associated variables in unadjusted analysis were included: sex, age, exacerbations in the previous 6 months in 2005 and heart disease. The absence of heart disease (no HD) is the reference variable in all regressions with the heart disease variable. Exacerbation was defined as an unplanned health care visit or course of oral steroids in the previous 6 months at baseline. HD = COPD patients with heart disease. New HD = COPD patients who developed heart disease between 2003 and 2012. No HD = COPD patients without heart disease.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire.

Figure 3 mMRC in 2005 and 2012 in COPD patients without heart disease (no HD), with heart disease diagnosed between 2003 and 2012 (new HD) and with heart disease at baseline (HD).

Notes: P-values given for statistical significance of change between 2005 and 2012 value.

Figure 4 Mean CCQ, total score and domains for 2005 and 2012 in COPD patients without heart disease (no HD), with heart disease diagnosed between 2003 and 2012 (new HD), and with heart disease at baseline (HD).

Note: P-values given for statistical significance of change between 2005 and 2012 value.
Abbreviation: CCQ, Clinical COPD Questionnaire.