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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015
AFRICA
183
years of implantation for those with four years or more of
battery life remaining at the time of implantation, provided
this depletion was not explained by high pacing outputs or
abnormal electrode impedance.
•
Device explantation for infection, malfunction and/or battery
depletion involved removal of the pacemaker or ICD due to
infection, malfunction or early battery depletion.
Data extraction
The cardiac clinic electrophysiology database was used to
identify the cases with re-used devices and the controls with new
devices. Data were extracted from clinical notes in the cardiac
clinic and additional information from pacemaker cards in the
cardiac catheterisation laboratory and clinical records. Patient
status was taken from clinical notes, the hospital electronic
record (Clinicom) and the records of the Department of Home
Affairs.
Statistical analysis
Categorical data were summarised as proportions and
continuous data as means and standard deviations or medians
and interquartile range. Categorical data were compared using
the chi-squared test, and continuous data using the Student’s
t
-test or Mann–Whitney test. All tests were two-sided and a
p
-value of
<
0.05 was considered significant. IBM SPSS (version
19, IBM Corp, NY, USA) was used to perform the analysis.
Results
Three patients with re-used pacemakers were excluded from
the analysis because of missing records. Data for 126 devices
inserted in 126 patients between 2003 and 2013 were analysed, of
which 102 (81%) were pacemakers (51 re-used and 51 new) and
24 (19%) were ICDs (12 re-used and 12 new). For the pacemaker
group, the median follow up for patients with re-used devices
(cases) was 15.1 months [interquartile range (IQR), 1.3–36.24
months] and for those with new devices (controls) it was 55.8
months (IQR, 20.3–77.8 months). In the ICD group, the median
follow up for patients with re-used devices (cases) was 35.9
months (IQR, 17.0–70.9 months) and for those with new devices
(controls) it was 45.7 months (IQR, 37.6–53.7 months).
Baseline characteristics of patients who received pacemakers
are shown in Table 1 and pacemaker parameters are shown in
Table 2. As expected, the re-used pacemaker cases had more
significant co-morbidities compared to the pacemaker controls.
They were more likely to have advanced cancer, CVA, advanced
COPD and dementia, with a poor baseline level of functioning,
mainly bed bound (due to CVA, dementia, atherosclerotic
and diabetic vasculopathies with lower limb amputations and
arthritis). There were no differences between the two groups with
regard to pacemaker parameters, as shown in Table 2.
Baseline characteristics of patients who received ICDs are
shown in Table 3 and there were no significant differences
between the two groups. ICD parameters are shown in Table 4
and there were no significant differences between the two groups.
The pacemaker group was analysed separately from the ICD
group. In the pacemaker group there were no device infections,
pacemaker malfunction, early battery depletion or explantation
of pacemaker due to infection, malfunction and early battery
depletion identified after a median follow up of 15.1 months
(IQR, 1.3–36.24 months) for the cases and 55.8 months (IQR,
20.3–77.8 months) for the controls.
For the pacemaker cases, 10 (19.6%) patients were followed
up for five years or more, 18 (35.3%) for one to five years, and
23 (45.1%) for less than a year. For the pacemaker controls, 23
(45.1%) patients were followed up for five years or more, 21
Table 1. Characteristics of patients who received pacemakers
Characteristics
Patients
with re-used
pacemakers
(cases)
Patients
with new
pacemakers
(controls)
p
-value
Sample size,
n
51
51
Age, years
74.33 ± 17.26 72.86 ± 16.13 0.658
Gender,
n
(%)
Male
24 (47.1)
24 (47.1)
1.00
Female
27 (52.9)
27 (52.9)
Co-morbidities,
n
(%)
Hypertension
26 (51)
35 (68.6)
0.069
Diabetes mellitus
7 (13.7)
13 (25.5)
0.135
Renal impairment
17 (33.3)
19 (37.3)
0.679
Cancer
7 (13.7)
3 (5.9)
0.49
Myocardial infarction
6 (11.8)
11 (21.6)
0.29
Cardiomyopathy
4 (7.8)
6 (11.8)
0.74
CVA
12 (23.5)
3 (5.9)
0.02
COPD
5 (9.8)
1 (2)
0.21
Dementia
10 (19.6)
1 (2)
0.008
Baseline function,
n
(%)
NYHA functional class 1
3 (5.9)
7 (13.7)
0.32
NYHA functional class 2
15 (29.5)
27 (52.9)
0.026
NYHA functional class 3
14 (27.5)
14 (27.5)
1.00
Wheelchair bound
4 (7.8)
3 (5.9)
1.00
Bed bound
15 (29.4)
0 (0)
<
0.0001
Indications
Sick sinus syndrome,
n
(%)
Yes
9 (17.6)
4 (7.8)
0.138
No
42 (82.4)
47 (92.2)
AV block,
n
(%)
Yes
38 (74.5)
43 (84.3)
0.22
No
13 (25.5)
8 (15.7)
Other,
n
(%)
Yes
4 (7.8)
4 (7.8)
No
47 (92.2)
47 (92.2)
1.00
First implantation,
n
(%)
43 (84.3)
45 (88.2)
0.565
Battery change,
n
(%)
8 (15.7)
6 (11.8)
0.565
Primary implanter
Cardiologist
25
25
1.00
Cardiology registrar
26
26
1.00
Temporal lead,
n
(%)
17 (33.3)
21 (41.2)
0.413
Follow up at 3 months,
n
(%)
Yes
26 (51)
43 (84.3)
<
0.0001
No
25 (49)
8 (15.7)
Follow up at 1 year,
n
(%)
Yes
19 (37.3)
38 (74.5)
<
0.0001
No
32 (62.7)
13 (25.5)
CVA = cerebrovascular accident; COPD = chronic obstructive pulmo-
nary disease; NYHA = New York Heart Association; AV block =
atrioventricular block;
n
= number; (%) = percentage; Other = atrial
fibrillation and heart failure.