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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 1, January/February 2016
38
AFRICA
the preferred method for revascularisation. If these requirements
are not met, fibrinolytic therapy may be performed for the
patients.
RV-STEMI requires immediate revascularisation in affected
patients. Revascularisation can be achieved with methods such
as percutaneous coronary intervention or thrombolytic therapy.
Current guidelines recommend the appropriate treatment of
coronary arteries after performing coronary angiography within
three to 24 hours following TT.
11,12
This study aimed to evaluate the effects of coronary
intervention on right ventricular systolic function by comparing
PPCI with PCI performed within three to 12 hours of TT, as
assessed by transthoracic echocardiography, in patients with
RV-STEMI.
Methods
This prospective, observational cohort study was carried out
between January 2012 and February 2013. We interviewed
210 patients who met the criteria for admission and had had
inferior myocardial infarction with right ventricular involvement
(RV-STEMI) for the first time. RV-STEMI was defined as new
ST-segment elevation
≥
0.1 mV at the J-point in two contiguous
inferior leads accompanied by new ST-segment elevation
≥
0.1
mV in the right ventricular leads (V3R–V4R).
Patients who had infection, heart muscle disease or chronic
inflammatory disease were not included in the study. At hospital
admission, the patients who had cardiogenic shock, chronic
pulmonary disease or systolic pulmonary artery pressure
>
35 mmHg, renal failure (creatinine
>
2.5 mg/dl) or a history
of cerebrovascular events were also excluded from the study.
Since RV systolic function was evaluated in our study, those
who had diseases such as pulmonary hypertension that could
impair the RV systolic function were excluded from the study. As
right heart catheterisation could not be applied during primary
PCI, the patients with echocardiographically measured systolic
pulmonary arterial pressure
>
35 mmHg were not included in the
study. Patients with unknown time of symptom onset or a StD
time longer than 12 hours were also not included in the study.
The patients were divided into two groups according to
admission to hospital; 132 patients who underwent PPCI
were identified as the first group. Seventy-eight patients who
underwent PCI in our centre within three to 12 hours after
receiving TT in other centres were included in the second group.
Our centre is a tertiary hospital and coronary intervention
facilities are available 24 hours a day, seven days a week. Patient
records are kept on a regular basis, starting at admission to the
emergency department. In addition to these data, the onset of
symptoms was sought from the patients themselves or their
relatives.
The exact time of patient admission in the emergency
department was identified as door-time. Symptom-to-door
(StD) time was determined by calculating the difference between
the two periods. The exact time the patient’s coronary balloon
had been inflated was recorded in the angiography laboratory.
The time lapse from the patient’s admission to the emergency
department to inflating the balloon was calculated as door-
to-balloon time (DtB). Symptom-to-balloon (StB) time was
calculated in addition to StD and DtB. Symptom-to-needle
(StN) time was calculated as the time from the initial onset of
symptoms to the start of thrombolytic drug administration.
The time lapse from the patient’s admission to the emergency
department to the start of thrombolytic drug administration was
calculated as door-to-needle time (DtN).
During the study, intervention was performed only for
the culprit arteries responsible for the infarction. Elective
interventions were performed for the other lesions. The invasive
treatment methods applied during PCI, and balloon and stent
diameters and lengths were recorded. The diameters of the vessels
with lesions were calculated from the coronary angiography
examinations.
Traditional variables that have been used to assess response
to TT were decrease in chest pain, ST-segment resolution and
reperfusion arrhythmias. Patients who had
<
50% ST-segment
resulution were excluded from the study. Patients who required
rescue PCI, patients scheduled for coronary artery bypass grafting
(CABG) or those who underwent percutaneous intervention for
all critical lesions due to haemodynamic instability were also
excluded from the study. Patients with a DtB time longer than
30 minutes in the PPCI group, and those with a door-to-needle
(DtN) time longer than 30 minutes in the TT group were not
included in the study.
All patients received dual antiplatelet therapy with
acetylsalicylic acid and clopidogrel (300–600 mg) loading dose
before coronary intervention. Peri-procedural anticoagulation
consisted of intravenous unfractioned heparin (70 IU/kg) in all
cases. Clopidogrel (75 mg per day) and acetylsalicylic acid (100
mg per day) were prescribed for at least one year. Blood samples
were collected from each subject immediately after presenting at
the emergency department. Cardiac enzymes, liver function tests,
kidney function tests, complete blood count and thyroid function
tests were performed on these samples.
Echocardiography
A Vivid-S5 echocardiography device is readily available in the
emergency department of our centre (General Electric Vingmed
Ultrasound, Horten, Norway, with a 3.6-MHz transducer).
Echocardiographic evaluation is performed rapidly in all patients
presenting at the emergency room (ER) with acute coronary
syndrome (ACS). Imaging is performed by the echocardiography
operator simultaneously while patients with STEMI are prepared
for coronary intervention. In our study, prolonged StD durations
were avoided in order to assess echocardiographic parameters.
Echocardiographic evaluation of the RV is more difficult
than that of the LV. An appropriate imaging window may
not be achieved due to restrictions caused by the sternum and
other anatomical structures. Therefore, patients with inadequate
echocardiographic imaging quality were excluded from the
present study.
American Society of Echocardiography (ASE)
recommendations were followed for the evaluation of RV
systolic function. RV end-systolic and end-diastolic diameters
were measured from the left parasternal long-axis view. RV
basal, mid and longitudinal diameters were measured from the
apical four-chamber view. Endocardium margins were drawn
from the tricuspid annulus to the RV apex and from there to the
opposite side of the tricuspid annulus in the apical four-chamber
view in order to calculate RV fractional area change (RV-FAC).
End-systole and end-diastole areas were individually calculated