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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 4, July/August 2016
220
AFRICA
89.1% received enoxaparin and only 9.4% received unfractionated
heparin; 67.2% had transthoracic echocardiography during their
hospital stay, of whom 76.9% had a left ventricular ejection
fraction (LVEF)
>
40%.
For type of acute myocardial infarction, 60.9%had a diagnosis
consistent with STEMI and 39.1% had NSTEMI. In the
NSTEMI arm, 44% of the patients received IIb/IIIa inhibitors,
mainly eptifibatide infusion, and 68% had a coronary angiogram
done before hospital discharge. The coronary anatomy was
consistent with significant atheromatous lesions in 79% of the
patients. Of those who had no coronary angiography, 60% had
non-invasive testing for myocardial ischaemia before discharge.
In the STEMI arm, 79.5% of patients received thrombolysis,
17.9%underwent rescue PCI and 2.6%did not receive reperfusion
therapy. None of the patients underwent primary PCI. The
door-to-needle time was less than 120 minutes in 45.2% of the
thrombolysis patients and 38.7% had no documentation of
door-to-needle time. The thrombolytic agent was tenecteplace
in 80.6% and steptokinase in 6.5% of patients. Only 51.6% of
the thrombolysis patients had an ECG done at 90 minutes post
thrombolysis, of whom 56.3% had achieved reperfusion. Of
the patients who did not achieve reperfusion, 66.7% underwent
rescue PCI. The coronary anatomy was consistent with significant
atheromatous lesions in 82.1% of the patients who underwent
angiographic studies.
Of the patients who underwent coronary angiography, 29%
were managed medically, 19.1% were referred for coronary
artery bypass grafting (CABG), and 40.4% had PCI with 84.2%
receiving drug-eluting stents. Of the patients who underwent
PCI, 87.5% achieved TIMI flow of grade 2 to 3.
Cardiogenic shock occurred in 17.2% of patients, new atrial
fibrillation in 6.3% and cardiac arrest in 3.1%. Sustained
ventricular tachycardia or ventricular fibrillation occurred in
5.3%, atrioventricular block in 4.7% and acute kidney injury
(creatinine
>
200 μmol/l) in 6.3%.
The mean duration of hospitalisation was 6.69 days.
In-hospital mortality rate was 9.4%. The mean in-hospital
probability of death according to the GRACE risk score was
16.05%.
Upon discharge from hospital, 84.5% were prescribed
β
-blockers, 48.3% were on ACE inhibitors or angiotensin
receptor blockers (ARBs), 96.6% were on low-dose aspirin,
96.6% on clopidogrel and 93.1% on statins.
Discussion
Cardiovascular risk factors have been determined from several
landmark studies, mostly performed in the Western world. The
African forum has recently embarked on some local studies.
The patient population in our study was similar in age
and gender to that of other African studies on traditional
cardiovascular risk factors in patients with confirmed coronary
artery disease.
2,17
The most prevalent risk factor in our study was
systemic hypertension, which reflects the findings in previous
studies. In the overall INTERHEART study, 39% of the
patient population had systemic hypertension, whereas in the
INTERHEART Africa arm, it was reported in 42.3% of
cases.
1,2,17,18
Emergency medical systems were not in place in our local
setting at the time we carried out this study, therefore first
medical contact was at the emergency department. Most patients
arrived after three hours from onset of chest pain. The initial
triage at the emergency department was not optimal with regard
to door-to-ECG, ECG-to-cardiologist and door-to-thrombolysis
times going beyond the recommended door-to-needle time of
30 minutes. The hospital is currently looking at a system that
will allow for immediate interactive communication with the
concerned cardiologist to advise on the management of these
patients.
The thrombolytic agent usedmost frequently was tenecteplace.
Almost all patients received antiplatelet and antithrombin
co-therapy as per the current guidelines. The gold standard of
acute management of ST-elevation myocardial infarction is
primary PCI, with thrombolytic therapy being effective when
given early. Thrombolysis was the standard approach in this
study.
Most patients in our study had an echocardiogram performed
during their hospital course. It is generally indicated that echo
assessment of cardiac anatomy and function be done in the first
24 to 48 hours after acute myocardial infarction.
4
Our data showed that the in-hospital mortality rate of
patients with a diagnosis of acute myocardial infarction was
9.4%. Despite the small size of the study population, this is
comparable to data derived from European studies. The mean
probability of in-hospital death in our study according to the
GRACE risk score was 16.05%.
Secondary preventive medication was prescribed for most
patients as per the standard recommendations. However ACE
inhibitors or ARBs were prescribed in less than 50% of patients.
Conclusion
The risk-factor assessment in our population of patients,
albeit small, was in keeping with traditional risk factors for
coronary artery disease found in other studies. The risk for acute
myocardial infarction was found to increase with higher income
and educational level in our black African population, in contrast
with findings in other African groups. With advances in the field
of cardiology, the local emergency medical system will improve
and timely invasive management of patients presenting with
acute myocardial infarction will be available. Currently, there
is room for improvement in reconciling the gap between actual
and recommended patient care. There is also a need to develop
local management protocols for patients with acute myocardial
infarction, based on local specialist experience and the available
facilities. The Nairobi Hospital is committed to putting in place
facilities to allow for primary PCI and early thrombolysis.
References
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Yusuf S, Hawken S. Effect of potentially modifiable risk factors associ-
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study): case-control study.
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2004;
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2.
Kamotho C, Ogola E, Joshi E. Cardiovascular risk factor profile of
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Furberg C, Wright J, Davis B, ALLHAT Collaborative Research Group.
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