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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 1, January/February 2019
AFRICA
31
artery was the most common culprit vessel, accounting for 51.6%
of STEMI and 37.8% of NSTE-ACS. Non-occlusive coronary
artery disease was found to be the underlying cause of ACS in
two patients with STEMI and three with NSTE-ACS. Of the
196 patients, 64 (32.8%) were found to have multi-vessel disease.
Of the 230 patients, 219 had documented left ventricular
function assessment done by two-dimensional echocardiography.
Left ventricular ejection fraction (LVEF) of patients with
STEMI was significantly lower than that of NSTE-ACS patients
(42.2 vs 50.3%,
p
<
0.001).
In-hospital outcomes are summarised in Table 2. Fifteen
patients with STEMI (14.9%) and three with NSTE-ACS (2.3%)
died while in hospital. The mean duration of event to death in
hospital was 11 days (
±
16.9) for STEMI patients and 21.3 days
(
±
19.3) for patients with NSTE-ACS.
Heart failure was the most common in-hospital complication
and was more likely to occur in STEMI patients (40.4 vs 16.3%,
p
<
0.001). One patient with STEMI and three with NSTE-ACS
suffered a stroke, while two patients in each category developed
a major bleed.
Survival status and out-of-hospital outcome data were
obtained in 184 of 212 patients (86.8%) discharged alive from
hospital. At the end of 30 days, 7.8% of the patients had died,
and at the end of one year after the event, 13.9% had died. The
mortality rate at both 30 days (13.7 vs 3.1%) and one year (20.8
vs 8.5%) was higher in patients with STEMI compared to those
with NSTE-ACS.
Kaplan–Meier survival curves for STEMI and NSTE-ACS
are displayed in Fig. 2. There was an early and significant
separation of the curves, and while this reduced over the course
of time, the difference remained significant at the end of 50
months of follow up (Fig. 2).
A total of 14 of the 212 patients discharged alive (6.6%) were
readmitted during the first year following the event. Of these, 10
patients suffered a recurrent myocardial infarction; one patient
was readmitted with a stroke, and three patients were admitted
due to major bleeding.
Discussion
With increasing awareness of the problem and access to expertise
and facilities, management of ACS in East and Central Africa
has seen some evolution in the past decade. In 2006, there were
only two functioning cathlabs in the region, both located in
Kenya. By 2012 this number grew to five, and in 2017 there were
12 cathlabs located within three countries in the region. A few
reports have described management practices and in-hospital
outcomes. However this is the first study in the region that
reports on both in- and out-of-hospital outcomes in patients who
have suffered ACS.
The mean age of patients was 60.5 (
±
12.8) years. This is
comparable to the mean age in the South African cohort in
the ACCESS-SA study,
12
but about four years younger than
that reported in a European registry, the EHS-ACS-II.
19
This
supports the notion that ACS is occurring at a younger age
in patients from SSA compared to western countries. Notably
in both the ACCESS-SA and EHS-ACS-II studies, STEMI
patients were significantly younger than patients with NSTE-
ACS (54.5 vs 60.5 years, and 62.5 vs 66.1 years, respectively).
This difference was however much less pronounced in our study
(58.7 and 61.9 years, respectively,
p
=
0.063).
As in other studies, an overwhelming male predominance
was noted in both subgroups. There were no significant
differences between the two groups with regard to other patient
characteristics, and these were comparable to those noted in
other studies.
In this study, 230 patients had a confirmed diagnosis of ACS
in the two-year period from January 2012 to December 2013.
This is more than twice the number of ACS admissions reported
at the same facility between April 2008 and May 2010, reflecting
the growing number of ACS patients seen and managed at the
centre.
STEMI comprised 44% of the patients presenting with
ACS in this study. This is comparable to data from both the
EHS-ACS-II and ACCESS-SA registries, in which STEMI
accounted for 47 and 41% of the patients’ diagnosis, respectively.
The most prominent major modifiable risk factor in our
population was hypertension, present in nearly 60% of the
patients. This is consistent with data from other regional and
international series. Diabetes appeared more prevalent (36.5%)
in our series than in other series (23.9% in ACCESS-SA and
14.1% in EHS-ACS-II). By contrast, smokers accounted for less
than a quarter of the ACS cases in our series, compared to nearly
double that in both of the above series.
Table 2. In-hospital events
Events
STEMI
(
n
=
101 )
NSTE-ACS
(
n
=
129)
p-
value
Death,
n
(%)
15 (14.9)
3 (2.3)
<
0.001
Heart failure,
n
(%)
40 (40.4)
21 (16.3)
<
0.001
Stroke,
n
(%)
1 (1)
3 (2.3)
0.64
Major bleed,
n
(%)
2 (2)
2 (1.6)
1
Repeat revascularisation,
n
(%)
0
0
STEMI, ST-elevation myocardial infarction, NSTE-ACS, non-ST-elevation
acute coronary syndrome.
Duration (months)
0.00 10.00 20.00 30.00 40.00 50.00 60.00
Cumulative survival
1.0
0.8
0.6
0.4
0.2
0.0
Diagnosis
STEMI
STEMI-censored
NSTE-ACS
NSTE-ACS-censored
Chi-Square DF P
Breslow
6.915 1 0.009
Tarone-Ware 5.726 1 0.017
Log Rank
4.188 1 0.041
Fig. 2.
Kaplan–Meier curves for survival.