Effect of Endobronchial Coils on Exercise Tolerance and Lung Functions in Patients with Severe Emphysema – A Retrospective Cohort Study of 48 Patients

Figures & data

Table 1 Baseline Clinical and Demographic Characteristics

Medical Center		Coils Treatment		Control	P value
		RMC	SZMC	RMC
Number of Patients		39	7	49
Age (mean ± SD)		64.1 ± 6.9		65.0±10.3	0.62
Male gender (%)		29 (63.0)		31 (63.3)	0.98
Baseline FEV1 %pred ^a		29.0 (23.0–38.2)		31.0 (21.5–42.0)	0.56
Baseline DLCO %pred ^a		39.0 (30.0–44.75)		39.0 (29.0–49.0)	0.58
Baseline TLC %pred ^a		127 (122–141)		111.5 (105.75–126.75)	0.01
Residual volume mL ^a		5.42 (4.32–5.96)		3.97 (3.22–5.01)	0.001
GOLD stage	4	23		18	0.21
	3	20		24
	2	2		5
	1	0		0
BODE score ^a		6 (5–7)		5 (4–7)	0.11
Supplemental oxygen (%)		8 (17.4)		6 (12.8)	0.53
Pack years ^a		50 (40–75)		50 (40–70)	0.80
DM (%)		7 (15.6)		14 (29.8)	0.10
HTN (%)		17 (37.8)		13 (27.7)	0.30
IHD (%)		10 (22.7)		8 (17.0)	0.49

Note: ^aData presented in median and IQR.

Abbreviations: RMC, Rabin Medical Center; SZMC, Shaare Zedek Medical Center; FEV1 %pred, forced expiratory volume in the first second percent predicted; DLCO %pred, carbon monoxide diffusing capacity percent predicted; Baseline TLC %pred, total lung capacity percent predicted; BODE score, BMI, obstruction, dyspnea, and exercise capacity; DM, diabetes mellitus; HTN, hypertension; IHD, ischemic heart disease; IQR, interquartile range.

Table 2 Within Group Comparison. Repeated Measures Analysis Showing Estimated Marginal Means of Six-Minute Walk Test Distance, FEV1 and Residual Volume at Baseline, 6 Months and 24 Months in Patients After Lung Volume Reduction with Endobronchial Coils

Pulmonary Function Test	N*	Baseline	6 Months	24 Months	P value
					Overall	Baseline vs 6 Months	Baseline vs 24 Months
6MWTD	23	331.0±101.4	372.9±76.8	338.8±104.8	0.04	0.10	1.0
FEV1	32	0.86±0.38	0.92±0.37	0.82±0.36	0.003	0.04	0.75
RV	25	5.28±1.59	4.91±1.43	5.07±1.30	0.45	0.60	1.0

Note: *The analysis included only patients with data in all time points.

Abbreviations: 6MWTD, six-minute walk test distance; FEV1, forced expiratory volume in the first second; RV, residual volume.

Table 3 Comparison of Six-Minute Walk Test Distance, FEV1, Residual Volume, Lung Transplant Recipients and Mortality Between the Endobronchial Coils and Control Group

		Endobronchial Coils N=46	Control N=49	P value
6MWTD^a	Baseline	325.0 (196.25–390.0)	342.0 (240–405)	0.58
	24 months	333.0 (262.5–390)	280 (210–405)	0.16
FEV1^a	Baseline	0.76 (0.61–0.97)	0.82 (0.63–1.06)	0.47
	24 months	0.77 (0.57–0.92)	0.73 (0.56–1.05)	0.78
RV^a	Baseline	5.42 (4.32–5.96)	3.97 (3.22–5.01)	0.001
	24 months	4.66 (3.89–6.21)	4.22 (3.28–5.49)	0.15
TLC^a	Baseline	7.83 (6.70–8.65)	6.87 (5.66–7.46)	0.03
	24 months	7.01 (6.14–8.36)	6.64(5.28–7.39)	0.10
Median follow-up time (months)^a		42.89 (29.90–59.66)	34.9 (21.59–56.96)	0.19
Mortality (%)		9 (20.0)	11 (22.4)	0.77
Median survival for deceased patients^a		20.27 (8.86–42.90)	18.16 (16.09–22.04)	0.87
Lung transplant (%)		6 (13.3)	5 (10.2)	0.63

Note: ^aData presented as median and IQR.

Abbreviations: 6MWTD, six-minute walk test distance; FEV1, forced expiratory volume in the first second; RV, residual volume; TLC, total lung capacity; IQR, interquartile range.

Table 4 Post Hoc Analysis for Predictors of Procedure Success

Demographic/Clinical Predictor	Success		P value
	+	–
n	12	34
Age	63.17±5.49	64.4±7.48	0.48
Male gender	9 (75.0)	20(58.8)	0.26
Heterogeneous emphysema	10 (83.3)	12 (35.3)	0.004
Baseline residual volume (%predicted)	235.5 (206.5–269.25)	249.0 (218.25–277.5)	0.39
Baseline FEV1 (%predicted)	35 (24.75–38.75)	26.5 (22.75–36.75)	0.23
Supplemental oxygen	0	8 (23.5)	0.07

Abbreviation: FEV1, forced expiratory volume in the first second.

Figure 1 Six-minute walk test distance (6MWTD), FEV1 and residual volume (RV) values for the intervention and control groups at baseline and at 6 and 24 months post procedure (intervention) or since follow-up commencement (control). Values for the control group are presented in Table S2.

Figure 2 Kaplan–Meier Curve presenting overall survival (death or lung transplant) for the intervention and control groups. Log Rank value is presented at the bottom of the graph.