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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 4, July/August 2021
AFRICA
179
of Cardiology, Chinese Medical Association, and (3) those
accompanied by paroxysmal, persistent or permanent AF based
on the relevant standards in the
Guideline for the Management
of Atrial Fibrillation
(2014). All patients gave informed consent
to this study, and the study was approved by the hospital ethics
committee.
Exclusion criteria were: (1) patients with cardiac dysfunction
caused by congenital heart disease, pulmonary heart disease,
primary valvular heart disease, or acute myocardial infarction,
(2) those with malignant tumours, (3) those with severe hepatic
or renal dysfunction, (4) those who failed to complete the study
as required due to mental disorders, or (5) those whose condition
of disease became stable for less than one week after the acute
phase of CHF.
The basic clinical parameters such as gender, age, smoking
history, body mass index, blood pressure, diabetes history
and hypertension history were collected. In addition, 5 ml
of fasting venous blood was drawn from each patient in the
morning, the day after percutaneous coronary intervention. It
was anticoagulated with EDTA and centrifuged at 3 000 rpm
and 4°C for 15 minutes.
The serum was examined using a fully automatic biochemical
analyser (Hitachi Labospect 008) to determine creatinine (Cr),
total cholesterol (TC), low-density lipoprotein cholesterol (LDL-
C), triglycerides (TG), high-density lipoprotein cholesterol
(HDL-C), fasting plasma glucose (FPG), and blood urea
nitrogen (BUN) levels. Neutrophils and lymphocytes were
counted using a haematology analyser (Sysmex XE2100). Within
24 hours of admission, left ventricular ejection fraction (LVEF)
was determined using a DW-F3 Doppler ultrasonic diagnostic
system (DAWEI).
All patients enrolled were followed up for five years through
the out-patient clinic, by re-examination, re-hospitalisation
and telephone. The occurrence of MACE was taken as the
end point of follow up. MACE include acute myocardial
infarction, congestive HF, ischaemic stroke, peripheral arterial
occlusion, recurrent angina, severe arrhythmia (persistent
ventricular tachycardia, ventricular fibrillation, new-onset
haemodynamically unstable AF or atrial flutter, high-grade
atrioventricular block, excluding reperfusion arrhythmia during
PCI), and cardiac death.
6
Statistical analysis
SPSS20.0 software (SPSS Inc, Chicago, IL, USA, 2011) was
used for statistical analysis. Quantitative data in line with normal
distribution are expressed as means ± standard deviation, and
one-way analysis of variance was performed for comparison
between groups. Numerical data are expressed as percentages, and
the chi-squared test was performed for intergroup comparison.
Factors related to MACE were analysed through multivariate
logistic regression models.
The diagnostic value of NLR for MACE was analysed using
the receiver operating characteristic (ROC) curves. Survival
curves were plotted using GraphPad 5 software, survival
analysis was conducted using the Kaplan–Meier method, and
the difference in survival curves was detected using the log-rank
test. A
p
-value
< 0.05 was considered statistically significant.
The corrected test level
α
= 0.0206 was used in the pairwise
comparison among groups.
Results
All 248 patients were divided into MACE and non-MACE
groups according to whether MACE occurred during the follow-
up period. Compared with the non-MACE group, the MACE
group had a higher age, higher proportion of cases with a
history of smoking and diabetes, LDL-C and FPG level, NLR
and NYHA functional class (III + IV), and lower LVEF. The
differences were statistically significant (
p
< 0.05) (Table 1).
With the presence or absence of MACE during the follow-up
period as the dependent variable, and the statistically significant
factors in univariate analysis as the independent variables,
multivariate logistic regression analysis was performed. The
results showed that higher age, LDL-C level and NLR, and
lower LVEF and diabetes, and NYHA class III and IV were
independent predictive factors for MACE (
p
< 0.05) (Table 2).
Based on the quartile of NLR, the patients were divided into
group A (NLR < 1.98), group B (1.98 ≤ NLR < 2.85), group C
(2.85 ≤ NLR < 4.62) and group D (NLR ≥ 4.62). The incidence
of MACE during follow up in each group is shown in Table 3. It
was found that the incidence of MACE rose with increased NLR
and the differences were statistically significant between groups
(
p
< 0.05). There were statistically significant differences in the
incidence of acute myocardial infarction, severe arrhythmia
and cardiac death among the four groups (
p
< 0.05), but the
incidence of other MACE showed no statistically significant
differences (
p
> 0.05).
According to the Kaplan–Meier curves of patients with CHF
and AF, the average duration of MACE was 49.31 months in
group A, 45.27 months in group B, 43.63 months in group C and
40.34 months in group D. It was confirmed using the log-rank
test that the survival curves of patients with MACE showed
statistically significant differences among the four groups (
p
<
0.05; group A vs group B;
p
= 0.006, group A vs group C;
p
=
Table 1. Baseline clinical data of MACE and non-MACE groups
[mean ± standard deviation/number (%)]
Index
Non-MACE
group (
n
= 152)
MACE
group (
n
= 96) t/
χ
2
p
-value
Age (year)
53.97 ± 10.19 67.24 ± 10.12 10.016 < 0.001
Male
92 (60.53)
64 (66.67)
0.951 0.33
BMI (kg/m
2
)
24.42 ± 2.11 24.67 ± 2.01 0.926 0.356
Smoking history
70 (46.05)
62 (64.58)
8.116 0.004
Systolic pressure (mmHg) 134.37 ± 12.89 135.18 ± 13.33 0.476 0.635
Diastolic pressure (mmHg) 84.25 ± 7.63 85.34 ± 8.17 1.066 0.287
Diabetes mellitus
60 (39.47)
55 (57.29)
7.512 0.006
Hypertension
87 (57.24)
58 (60.42)
0.245 0.621
LVEF (%)
58.07 ± 6.18 39.42 ± 3.98 26.312 < 0.001
Cr (μmol/l)
75.91 ± 22.54 74.45 ± 20.32 0.516 0.606
TC (mmol/l)
4.21 ± 0.51
4.22 ± 0.49 0.153 0.879
TG (mmol/l)
1.50 ± 0.06
1.51 ± 0.10 0.984 0.326
LDL-C (mmol/l)
2.84 ± 0.12
2.96 ± 0.15 6.953 < 0.001
HDL-C (mmol/l)
1.27 ± 0.19
1.26 ± 0.15 0.437 0.663
FPG (mmol/l)
6.93 ± 0.65
7.63 ± 0.96 6.846 < 0.001
BUN (mmol/l)
5.44 ± 1.39
5.46 ± 1.33 0.112 0.911
NLR
2.38 ± 0.21
4.32 ± 0.38 32.38 < 0.001
NYHA functional class
47.616 < 0.001
I + II
100 (65.79)
20 (20.83)
III + IV
52 (34.21)
76 (79.17)
BMI: body mass index; BUN: blood urea nitrogen; Cr: creatinine; FPG: fasting
plasma glucose; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-
density lipoprotein cholesterol; LVEF: left ventricular ejection fraction; MACE:
major adverse cardiovascular event; NLR: neutrophil-to-lymphocyte ratio;
NYHA: New York Heart Association; TC: total cholesterol; TG: triglycerides.