Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://www.cardiologyres.org

Original Article

Volume 7, Number 3, June 2016, pages 95-103

Cardiac Resynchronization Therapy Leads to Improvements in Handgrip Strength

Figure 1. The markers of response to cardiac resynchronization therapy, at time zero (baseline) before implantation, 6 and 12 months following CRT implantation in responders (white): (A) 6-minute walk distance (6MWD); (B) peak VO₂; (C) Minnesota Living With Heart Failure Questionnaire (MLWHFQ) score; (D) left ventricular end-diastolic volume (LVEDV). Differences in data from baseline to 6 and 12 months compared using one-way ANOVA with repeated measures.

Figure 2. The markers of response to cardiac resynchronization therapy, at time zero (baseline) before implantation, 6 and 12 months following CRT implantation in non-responders (black). (A) 6-minute walk distance (6MWD); (B) peak VO₂; (C) Minnesota Living With Heart Failure Questionnaire (MLWHFQ) score; (D) left ventricular end-diastolic volume (LVEDV). Data during follow-up compared using one-way ANOVA with repeated measures, with no significant difference.

Figure 3. The peak workload (watts) measured during cardiopulmonary exercise testing in (A) responders (white) and (B) non-responders (black) at time zero (baseline) before implantation and then 6 and 12 months following CRT, compared using one-way ANOVA with repeated measures.

Figure 4. Mean handgrip strength in the left (A) and right hand (B) at zero (baseline), 6 and 12 months following cardiac resynchronization therapy (responders in solid gray line and non-responders in solid black line) with standard error bars.

Figure 5. Correlation between handgrip strength (right and left) and 6-minute walk distance (6MWD) in the left (A) and right (B) hands both responders and non-responders, compared using Pearson’s correlation coefficient.

**Table 1.** Baseline Characteristics of Responders and Non-Responders Pre-CRT Implantation
	Responders (N = 14)	Non-responders (N = 5)	P value
Mean or number given in right hand column and % or SD given in left hand column. ^Comparisons between groups analyzed using two-tailed unpaired Student’s t-test unless categorical data (*) compared using Fisher’s exact test. ACE: angiotensin converting enzyme inhibitor; ARB: angiotensin receptor blocker; CRT: cardiac resynchronization therapy; ECG: electrocardiography; EF: ejection fraction; LVEDV: left ventricular end-diastolic volume; QRSd: QRS duration.
Demographics
Age (years)	68.4	9.8	71.8	4.2	0.53
Gender (male)	13	93%	5	100%	0.99*
Handedness (right)	14	100%	5	100%	0.99*
Body mass index (kg/m²)	29.6	3.98	26.5	4.41	0.18
Ischemic heart disease	8	57%	3	60%	0.99*
Hypercholesterolemia	10	72%	4	80%	0.99*
Hypertension	7	50%	2	40%	0.99*
Chronic kidney disease	4	29%	4	80%	0.11*
Diabetes	5	36%	1	20%	0.99*
ECG/echocardiography
QRSd (ms)	163.0	22.8	155.5	20.9	0.55
EF (%)	25.6	8.0	25.8	8.5	0.44
Medications
ACEI/ARB	13	93%	5	100%	0.99*
Beta-blocker	12	86%	5	100%	0.99*
Loop diuretic	14	100%	5	100%	0.99*
Spironolactone	9	64%	4	80%	0.99*
Markers of response
6MWD (m)	374.0	112.8	337.0	144.7	0.23
LVEDV (mL)	201.5	72.5	159.0	80.8	0.37
MLWHFQ	44.4	22.9	52.8	22.7	0.33
Peak VO₂ (mL/kg/min)	12.5	1.6	13.9	2.7	0.25
Hand grip strength (kgf)
Left	34.4	11.4	33.0	5.3	0.42
Right	35.7	12.5	31.2	12.2	0.25

Table 1. Baseline Characteristics of Responders and Non-Responders Pre-CRT Implantation

Responders (N = 14)

Non-responders (N = 5)

P value

Mean or number given in right hand column and % or SD given in left hand column. ^Comparisons between groups analyzed using two-tailed unpaired Student’s t-test unless categorical data (*) compared using Fisher’s exact test. ACE: angiotensin converting enzyme inhibitor; ARB: angiotensin receptor blocker; CRT: cardiac resynchronization therapy; ECG: electrocardiography; EF: ejection fraction; LVEDV: left ventricular end-diastolic volume; QRSd: QRS duration.

Demographics

Age (years)

68.4

9.8

71.8

4.2

0.53

Gender (male)

93%

100%

0.99*

Handedness (right)

100%

0.99*

Body mass index (kg/m²)

29.6

3.98

26.5

4.41

0.18

Ischemic heart disease

57%

60%

0.99*

Hypercholesterolemia

72%

80%

0.99*

Hypertension

50%

40%

0.99*

Chronic kidney disease

29%

80%

0.11*

Diabetes

36%

20%

0.99*

ECG/echocardiography

QRSd (ms)

163.0

22.8

155.5

20.9

0.55

EF (%)

25.6

8.0

25.8

8.5

0.44

Medications

ACEI/ARB

93%

100%

0.99*

Beta-blocker

86%

100%

0.99*

Loop diuretic

100%

0.99*

Spironolactone

64%

80%

0.99*

Markers of response

6MWD (m)

374.0

112.8

337.0

144.7

0.23

LVEDV (mL)

201.5

72.5

159.0

80.8

0.37

MLWHFQ

44.4

22.9

52.8

22.7

0.33

Peak VO₂ (mL/kg/min)

12.5

1.6

13.9

2.7

0.25

Hand grip strength (kgf)

Left

34.4

11.4

33.0

5.3

0.42

Right

35.7

12.5

31.2

12.2

0.25

**Table 2.** Markers of Response at 0 (Baseline), 6 and 12 Months Follow-Up in Responders and Non-Responders
Markers of response	Baseline, mean ± SD	6 months, mean ± SD	12 months, mean ± SD	One-way ANOVA with repeated measures P value
LVEDV: left ventricular end-diastolic volume; MLWHFQ: Minnesota Living With Heart Failure Questionnaire; 6MWD: 6-minute walk distance.
Responders (N = 14)
6MWD (m)	374.0 ± 112.8	391.0 ± 108.1	418.1 ± 105.3	< 0.05	< 0.05
LVEDV (mL)	175.1 ± 67.2	157.0 ± 77.3	121.3 ± 72.0	< 0.05	< 0.05
MLWHFQ/105	44.4 ± 22.9	24.4 ± 19.1	24.1 ± 21.3	< 0.05	< 0.05
Peak VO₂ (mL/kg/min)	12.5 ± 1.6	14.1 ± 2.7	14.7 ± 1.5	< 0.05	< 0.01
Non-responders (N = 5)
6MWD (m)	337.0 ± 144.7	279.2 ± 155.5	279.6 ± 113.8	0.34
LVEDV (mL)	159.0 ± 80.8	172.4 ± 126.2	145.6 ± 88.8	0.63
MLWHFQ/105	52.8 ± 22.7	37.0 ± 20.6	36.4 ± 26.7	0.31
Peak VO₂ (mL/kg/min)	13.9 ± 2.7	11.5 ± 4.1	12.8 ± 3.9	0.21

Table 2. Markers of Response at 0 (Baseline), 6 and 12 Months Follow-Up in Responders and Non-Responders

Markers of response

Baseline, mean ± SD

6 months, mean ± SD

12 months, mean ± SD

One-way ANOVA with repeated measures P value

Baseline vs. 6 months

Baseline vs. 12 months

LVEDV: left ventricular end-diastolic volume; MLWHFQ: Minnesota Living With Heart Failure Questionnaire; 6MWD: 6-minute walk distance.

Responders (N = 14)

6MWD (m)

374.0 ± 112.8

391.0 ± 108.1

418.1 ± 105.3

< 0.05

LVEDV (mL)

175.1 ± 67.2

157.0 ± 77.3

121.3 ± 72.0

< 0.05

MLWHFQ/105

44.4 ± 22.9

24.4 ± 19.1

24.1 ± 21.3

< 0.05

Peak VO₂ (mL/kg/min)

12.5 ± 1.6

14.1 ± 2.7

14.7 ± 1.5

< 0.05

< 0.01

Non-responders (N = 5)

6MWD (m)

337.0 ± 144.7

279.2 ± 155.5

279.6 ± 113.8

0.34

LVEDV (mL)

159.0 ± 80.8

172.4 ± 126.2

145.6 ± 88.8

0.63

MLWHFQ/105

52.8 ± 22.7

37.0 ± 20.6

36.4 ± 26.7

0.31

Peak VO₂ (mL/kg/min)

13.9 ± 2.7

11.5 ± 4.1

12.8 ± 3.9

0.21

**Table 3.** Handgrip Strength at 0 (Baseline), 6 and 12 Months Follow-Up in Responders and Non-Responders
Handgrip strength	Baseline, mean ± SD	6 months, mean ± SD	12 months, mean ± SD	One way ANOVA with repeated measures P value
kgf: kilograms of force; SD: standard deviation.
Responders (N = 14)
Left (kgf)	34.4 ± 11.4	39.7 ± 10.8	40.3 ± 11.3	< 0.01	< 0.001
Right (kgf)	35.7 ± 12.5	39.8 ± 11.5	42.2 ± 11.2	< 0.01	< 0.001
Non-responders (N = 5)
Left (kgf)	33.0 ± 5.3	27.6 ± 8.9	25.0 ± 11.7	0.30
Right (kgf)	31.2 ± 12.2	30.8 ± 9.9	29.8 ± 8.1	0.66

Table 3. Handgrip Strength at 0 (Baseline), 6 and 12 Months Follow-Up in Responders and Non-Responders

Handgrip strength

Baseline, mean ± SD

6 months, mean ± SD

12 months, mean ± SD

One way ANOVA with repeated measures P value

Baseline vs. 6 months

Baseline vs. 12 months

kgf: kilograms of force; SD: standard deviation.

Responders (N = 14)

Left (kgf)

34.4 ± 11.4

39.7 ± 10.8

40.3 ± 11.3

< 0.01

< 0.001

Right (kgf)

35.7 ± 12.5

39.8 ± 11.5

42.2 ± 11.2

< 0.01

< 0.001

Non-responders (N = 5)

Left (kgf)

33.0 ± 5.3

27.6 ± 8.9

25.0 ± 11.7

0.30

Right (kgf)

31.2 ± 12.2

30.8 ± 9.9

29.8 ± 8.1

0.66