Fræðigrein

Introduction: Cardiac rehabilitation is a well-established treatment for patients with coronary artery disease but limited information is available for Icelandic patients. The aim of this study was to investigate whether Phase II cardiac rehabilitation at the HL rehabilitation center was improving physical health and quality of life of patients.

Material and methods: Patients that had undergone coronary artery intervention were invited to participate. There were 64 participants (of 65 invited) that started in the study and 48 that finished. On average participants attended 2.1 sessions pr. week, for 8.4 weeks. Measurements performed: endurance (W/kg), blood pressure and pulse responses from an exercise test and body mass index (kg/m²). To measure health related quality of life the SF-36v2 questionnaire was used.

Results: Endurance improved by 14.4% (p<0,001) and a 6.1% increase was seen in peak pulse (p=0.001). The group was divided by age (32-64 years and 65-86 years) and both age groups improved their endurance number similarly (14.6% and 14.1%) but only the older age group improved peak pulse significantly or 7.2% (p=0.007). When the group was divided according to number of training sessions per week there was a 10.1% increase in endurance in the group that had fewer sessions but it was 19.8% in those that attended more sessions (p<0.001).  Participants assessed that their physical health, measured with a questionnaire, had improved at the end of training (p=0.003). When the group was divided into two groups according to how they measured their physical health at the beginning of the study there was a significant increase of 15.1% in physical health in those that estimated worse quality of life at the beginning of the study, but the other group had an increase of 1.2%.

Conclusion: Cardiac rehabilitation improves endurance and physical wellbeing in patients. Training magnitude is essential for improvement.

Figure 1.  The research design

Table I. Descriptive characteristics.

	Lowest value	Highest value	Mean
Number of weeks of training	5.0	20.9	8.4
Training sessions (per week)	0.4	3.0	2.1
Age (years)	32	86	65
Height (cm)	160	192	177
Weight (kg) (Measure 1)	54	141	89,8
Weight (kg) Measure 2)	54	140	89,5
Body mass index (kg/m2) (Measure 1)	21	44	29
Watts (Measure 1)	75	250	149
Watts (Measure 2)	90	288	169
	Women	Men	Total
Gender distribution of participants	6 (12.5%)	42 (87.5%)	48

 

Table II. Measurement at baseline and after the training period.

	n	Baseline	After training period	Difference	Difference (%)	p-value
Endurance (W/kg)	48	1.7 ± 0.5	1.9 ± 0.5	0.2 ± 0.2	14.4	<0.001
32-64 years	23	1.8 ± 0.5	2.1 ± 0.6	0.3 ± 0.2	14.6	<0.001
65-86 years	25	1.5 ± 0.4	1.7 ± 0.4	0.2 ± 0.2	14.1	<0.001
Body mass index, kg/m2	48	28.6 ± 4.5	28.5 ± 4.4	-0.1 ± 0.6	-0.4	0.251
Resting pulse rate	48	67.7 ± 10.9	65.5 ± 11.7	-2.2 ± 8.9	-3.2	0.095
Peak pulse rate	48	125.2 ± 22.0	132.7 ± 21	7.6 ± 14.5	6.1	0.001
32-64 years	23	135.5 ± 20.2	142.2 ± 19.8	6.7 ± 14.9	5.0	0.041
65-86 years	25	115.6 ± 19.4	124.0 ± 18.3	8.4 ± 14.3	7.2	0.007
Systolic (min)	48	129 ± 20	133 ± 21	4.3 ± 20.6	3.4	0.150
Diastolic (min)	48	83 ± 12	83 ± 10	-0.7 ± 11.6	-0.8	0.684
Systolic (max)	48	183 ± 25	186 ± 27	3.4 ± 21	1.9	0.269
Diastolic (max)	48	95 ± 11	94 ± 14	-0.1 ± 11	-0.1	0.937

Value: Average ± standard deviation

Table III. Physical measurements and number of training sessions.

	0.4 – 2.1 training sessions (n=25)				2.2 – 3.0 training sessions (n=23)
	Baseline	After training period	Difference (%)	p-value	Measure 1	Measure 2	Difference  (%)	p-value
Endurance (W/kg mean)	1.8 ± 0.5	2.0 ± 0.5	10.1	<0.001	1.5 ± 0.4	1.8 ± 0.5	19.8	<0.001
Body mass index, kg/m2	28.3 ± 4.4	28.3 ± 4.4	0.0	0.932	29.0 ± 4.8	28.7 ± 4.5	-0.8	0.112
Resting pulse rate	68.0 ± 10.1	64.8 ± 10.1	-4.7	0.080	67.2 ± 12	66.1 ± 13.4	-1.6	0.574
Peak pulse rate	129.9 ± 19.1	132.3 ± 18.1	1.8	0.323	120.0 ± 24.1	133.2 ± 24.1	11.0	<0.001
Systolic (min)	133 ± 22	134 ± 19	0.7	0.786	124 ± 17	132 ± 23	6.5	0.119
Diastolic (min)	84 ± 11	81 ± 9.1	-3.8	0.236	82 ± 13	84 ± 11	2.5	0.275
Systolic (max)	188± 30	187 ± 30.2	-0.3	0.877	177 ± 17	184 ± 22	4.4	0.113
Diastolic (max)	95 ± 12	91 ± 10.0	-4.1	0.073	94 ± 10	98± 16	4.2	0.080

Value: Average ± standard deviation

Table IV. Health quality of  life - SF-36v2.

	n1	Measure 1	Measure 2	Difference	Difference (%)	p-value
Physical health (PCS)3	41	47.7 ± 7.1	51.2 ± 6.5	3.4 ± 6.9	7.2	0.003
0.4 - 2.1 sessions	21	48.7 ± 7.7	51.5 ± 6.3	2.9 ± 7.3	5.9	0.090
2.2 - 3.0 sessions	20	46.8 ± 6.6	50.8 ± 6.9	4.0 ± 6.6	8.6	0.014
Worse initial health2	20	42.1 ± 5.1	48.4 ± 6.2	6.4 ± 7.9	15.1	0.002
Better initial health2	21	53.1 ± 3.7	53.8 ± 5.9	0.6 ± 4.4	1.2	0.523
Mental health (MCS)4	41	52 ± 8	53.1 ± 7.3	1.1 ± 7.2	2.2	0.314
0.4 - 2.1 sessions	21	54.3 ± 5.6	55.4 ± 6.1	1.1 ± 6.4	2.0	0.446
2.2 - 3.0 sessions	20	49.5 ± 9.4	50.7 ± 7.8	1.2 ± 8.1	2.4	0.515

1 41 of 48 answered both questionnaires adequately.
2 Self estimate on physical health is divided into two categories 1) score 29-47 and 2) score 48-60. Higher number means better health.
3 PCS: Physical component summary. 4 MCS: Mental component summary.