Impact of Cardiovascular and Metabolic Comorbidities on Long-term Outcomes of Home-based Pulmonary Rehabilitation in COPD

Figures & data

Table 1 Baseline Description of the Population

	All Patients	Reference	Metabolic	Cardiovascular	p
	n=419	n=102	n=122	n=195
Age (years)	64.1±11.2	58.2±10.6	62.0±11.1	68.5±9.6	<0.001
Male n (%)	279 (66.6)	65 (63.7)	70 (57.4)	144 (73.8)	0.008
BMI (kg/m^2)	27.1±7.7	21.2±3.8	30.5±6.7	28.1±8.1	<0.001
Obesity n (%)	128 (30.7)	0	62 (50.8)	66 (34.0)	<0.001
Underweight n (%)	95 (22.8)	51 (50)	8 (6.6)	36 (18.6)	<0.001
Smoking status n (%)
Current smoker	55 (13.5)	9 (8.9)	19 (16)	27 (14.4)	0.26
Former smoker	330 (80.9)	87 (86.1)	90 (75.6)	153 (81.4)
Never smoker	23 (5.6)	5 (5)	10 (8.4)	8 (4.3)
Spirometry
FEV1 (L)	1.1 ±0.5	1.0±0.6	1.2±0.6	1.0±0.4	0.015
FEV1 (% predicted)	39.2±17.0	34.7±17.3	43.7±16.1	38.8±16.7	<0.001
FVC (L)	2.2±0.9	2.4±1.0	2.3±0.9	2.0±0.8	0.007
FVC (% predicted)	64.4±19.7	67.3±21.2	68.5±19.6	59.5±18.0	0.002
FEV1/FVC (%)	50.5±14.4	50.7±14.4	52.4±13.3	49.2±14.9	0.30
COPD stages n (%)
GOLD 1	2 (0.6)	1 (1.1)	0	1 (0.6)	0.02^a
GOLD 2	77 (21.6)	15 (16.7)	31 (29.2)	31 (19.3)
GOLD 3	155 (43.4)	33 (36.7)	50 (47.2)	72 (44.7)
GOLD 4	123 (34.5)	41 (45.6)	25 (23.6)	57 (37.5)
Home ventilatory equipment n (%)
LTOT	276 (65.9)	62 (60.8)	68 (55.7)	146 (74.9)	0.001
NIV	138 (32.9)	27 (26.5)	32 (26.2)	79 (40.5)	0.009
CPAP	34 (8.1)	1 (1.0)	16 (13.1)	17 (8.7)	0.004

Notes: Results are given as mean±standard deviation for quantitative variables or frequencies (percentage) for categorical variables. Obesity and underweight are defined by BMI ≥30 kg/m² and ≤21 kg/m², respectively. p-value <0.05 are considered statistically significant. ^aDue to too small Gold 1 size, Gold 1 and 2 were pooled together for the statistical analysis comparing patient repartitions between GOLD 1+2, GOLD 3 and GOLD 4.

Abbreviations: BMI, body mass index; CPAP, continuous positive airway pressure; FEV₁, forced expiratory volume in the first one second; FVC, forced vital capacity; GOLD, global strategy for the diagnosis, management, and prevention of chronic obstructive lung disease; LTOT, long-term oxygen therapy; NIV, noninvasive ventilation.

Table 2 Patients’ Reported Cardiovascular and Metabolic Comorbidities

	Whole Population n=419	Metabolic n=122	Cardiovascular n=195
Cardiovascular diseases n (%)	195 (46.5)	0	195 (100.0)
Ischemic heart disease	93 (22.2)	0	93 (47.7)
Chronic heart failure	54 (12.9)	0	54 (27.7)
Heart rhythm disorder	76 (18.1)	0	76 (39.0)
Peripheral arterial disease	29 (6.9)	0	29 (14.9)
Pulmonary hypertension	14 (3.3)	0	14 (7.2)
Metabolic diseases n (%)	270 (64.6)	122 (100.0)	148 (75.9)
Hypertension	171 (40.8)	69 (56.6)	102 (52.3)
Obesity	128 (30.7)	62 (50.8)	66 (34.0)
Hypercholesterolemia	94 (22.4)	34 (27.9)	60 (30.8)
Diabetes mellitus	91 (21.7)	37 (30.3)	54 (27.7)

Figure 1 Flowchart of the whole population.

Abbreviation: PR, pulmonary rehabilitation.

Table 3 Absolute Variations of Exercise Capacity, Quality of Life and Anxiety-depression for each Group of Patients

	Reference	Metabolic	Cardiovascular	p
6MST
M0	307 ± 16	340 ± 13	308 ± 13	0.14
M2-M0	38 ± 14	80 ± 11	54 ± 11	0.054
M8-M0	23 ± 17	66 ± 14	38 ± 15	0.064
M14-M0	14 ± 19	72 ± 15	37 ± 17	0.15
VSRQ
M0	29.6 ± 1.8	33.6 ± 1.5	31.2 ± 1.4	0.24
M2-M0	7.7 ± 1.6	8.3 ± 1.3	6.8 ± 1.2	0.34
M8-M0	6.4 ± 1.7	9.7 ± 1.4	8.3 ± 1.3	0.71
M14-M0	6.3 ± 1.8	8.5 ± 1.5	5.6 ± 1.4	0.36
HAD
M0	18.7 ± 0.9	17.9 ± 0.7	17.6 ± 0.7	0.61
M2-M0	−2.5 ± 0.7	−3.6 ± 0.6	−2.8 ± 0.5	0.45
M8-M0	−3.3 ± 0.8	−5.0 ± 0.6	−3.5 ± 0.6	0.13
M14-M0	−2.9 ± 0.8	−5.0 ± 0.7*,**	−2.6 ± 0.6	0.021
HA
M0	10.0 ± 0.5	10.4 ± 0.4	10.0 ± 0.4	0.75
M2-M0	−0.5 ± 0.4	−1.7 ± 0.3	−1.2 ± 0.3	0.088
M8-M0	−1.5 ± 0.5	−2.1 ± 0.4	−1.6 ± 0.4	0.51
M14-M0	−1.0 ± 0.5	−2.2 ± 0.4	−1.6 ± 0.4	0.16
HD
M0	8.8 ± 0.5	7.5 ± 0.4	7.8 ± 0.4	0.15
M2-M0	−1.9 ± 0.5	−2.0 ± 0.3	−1.7 ± 0.3	0.77
M8-M0	−1.7 ± 0.4	−3.0 ± 0.3	−2.0 ± 0.3	0.051
M14-M0	−1.9 ± 0.5	−2.9 ± 0.4**	−1.1 ± 0.4	0.004

Notes: Basal evaluation (M0) and evolutions of exercise capacity, quality of life and anxiety and depression assessed with the 6MST, VSRQ and HAD, respectively for each group of patients at the end of pulmonary rehabilitation (M2) and at 6 and 12 months after the end of PR (M8 and M14, respectively). Results are adjusted to age, sex, BMI, FEV₁ and LTOT status, and given as mean±standard error. *p<0.05 when comparing Metabolic group to Reference group, **p<0.05 when comparing Cardiovascular group to Metabolic group. p<0.05 are considered significant.

Abbreviations: 6MST, 6-min stepper test; HAD, hospital anxiety and depression scale; HA, anxiety HAD subscore; HD, depression HAD subscore; VSRQ, visual simplified respiratory questionnaire.

Table 4 Absolute Variations of Exercise Capacity, Quality of Life and Anxiety-depression for the Whole Population

	M2-M0	M8-M0	M14-M0	p
6MST (number of steps)	+64 ± 6	+41 ± 8	+43 ± 9	<0.001
VSRQ (score)	+7.8 ± 0.7	+8.1 ± 0.8	+6.8 ± 0.8	<0.001
HAD (score)	−3.0 ± 0.3	−4.0 ± 0.3	−3.4 ± 0.4	<0.001
HA	−1.3 ± 0.2	−1.9 ± 0.2	−1.6 ± 0.2	<0.001
HD	−1.8 ± 0.2	−2.2 ± 0.2	−1.8 ± 0.2	<0.001

Notes: Absolute variations of exercise capacity, quality of life and anxiety and depression assessed with the 6MST, VSRQ and HAD, respectively, compared to M0. Results are given as mean±standard error. p<0.05 are considered significant.

Abbreviations: 6MST, 6-min stepper test (MCID 40); HAD, hospital anxiety and depression scale (MCID 1.5); HA, anxiety HAD subscore (MCID 1.5); HD, depression HAD subscore (MCID 1.5); M2, end of pulmonary rehabilitation; M8, 6 months after PR completion; M14, 12 months after PR completion; VSRQ, visual simplified respiratory questionnaire (MCID 3.4).

Table 5 Comparisons to Baseline of Exercise Capacity, Quality of Life and Anxiety-depression Assessed at the End of the Rehabilitation Program and after 6 and 12 Months for each Group of Patients

	Reference		Metabolic		Cardiovascular
	Values	p (vs M0)	Values	p (vs M0)	Values	p (vs M0)
6MST
M0	307±16		340±13		308±13
M2	347±18	0.001	425±14	<0.0001	370±14	<0.0001
M8	332±21	0.13	407±17	<0.0001	354±17	0.001
M14	322±22	0.40	415±18	<0.0001	348±19	0.013
VSRQ
M0	29.6 ±1.8		33.6±1.5		31.2±1.4
M2	38.3 ±1.9	<0.0001	41.6±1.6	<0.0001	38.0±1.5	<0.0001
M8	37.0 ±2.0	<0.0001	42.8±1.7	<0.0001	39.6±1.5	<0.0001
M14	37.0 ±2.0	<0.0001	41.5±1.7	<0.0001	36.9±1.6	0.0001
HAD
M0	18.7±0.9		17.9±0.7		17.6±0.7
M2	15.6±0.9	<0.0001	14.4±0.7	<0.0001	14.9±0.7	<0.0001
M8	14.8±0.9	<0.0001	13.0±0.8	<0.0001	14.3±0.7	<0.0001
M14	15.1±0.9	<0.0001	13.0±0.8	<0.0001	15.1±0.7	0.0001
HA
M0	10.0±0.5		10.4±0.4		10.0±0.4
M2	9.2±0.5	0.035	8.6±0.4	<0.0001	8.7±0.4	<0.0001
M8	8.2±0.6	0.0001	8.1±0.5	<0.0001	8.3±0.4	<0.0001
M14	8.7±0.6	0.005	8.1±0.5	<0.0001	8.3±0.4	<0.0001
HD
M0	8.8±0.5		7.5±0.4		7.8±0.4
M2	6.5±0.5	<0.0001	5.8±0.4	<0.0001	6.3±0.4	<0.0001
M8	6.7±0.5	<0.0001	4.9±0.4	<0.0001	5.9±0.4	<0.0001
M14	6.5±0.5	<0.0001	4.9±0.5	<0.0001	6.9±0.4	0.018

Notes: Comparisons to baseline (M0) for each group of patients of exercise capacity, quality of life and anxiety and depression assessed with the 6MST, VSRQ and HAD, respectively at the end of pulmonary rehabilitation (M2) and at 6 and 12 months after the end of PR (M8 and M14, respectively). Results are adjusted to age, sex, BMI, FEV₁ and LTOT status, and given as mean±standard error. p<0.05 are considered significant.

Abbreviations: 6MST, 6-min stepper test; HAD, hospital anxiety and depression scale; HA, anxiety HAD subscore; HD, depression HAD subscore; VSRQ, visual simplified respiratory questionnaire.

Figure 2 Proportion of patients exceeding the MCID for exercise capacity, quality of life and anxiety-depression score according to the group.

Notes: Proportion of patients exceeding the MCID for exercise tolerance assessed by (A) the 6-min stepper test (6MST – MCID 40 steps), (B) quality of life assessed by the visual simplified respiratory questionnaire (VSRQ – MCID 3.4 points) and (C) anxiety-depression assessed by the hospital anxiety and depression scale global score (HAD – MCID 1.5 points). Group 1, Reference Group; Group 2, Metabolic Group; Group 3, Cardiovascular Group.

Abbreviations: 6MST, 6-min stepper test; HAD, hospital anxiety and depression scale; MCID, minimal clinically significant difference; VSRQ, visual simplified respiratory questionnaire.