Background: Anaemia is a medical disorder that is defined by a decrease in the amount of red blood cells and a lower concentration of haemoglobin in the bloodstream. Anaemia is a widely acknowledged factor that worsens myocardial ischaemia when there is limited coronary reserve. Anaemia has been demonstrated to be a distinct risk factor for unfavorable cardiovascular outcomes in population cohorts of patients with heart failure. Objective: To determine the relationship between in-hospital outcome of patients with ACS and anemia. Methodology: Prospective, Observational study was carried out in the Department of Cardiology, Northeast Medical College, Sylhet, Bangladesh. Considering the inclusion and exclusion criteria, patients who were admitted with acute coronary syndromes with low hemoglobin level was taken as study population. The study population were divided into two groups in the basis of hemoglobin level in group-I baseline hemoglobin ≤12 gm/dl as anemic and in group-II baseline hemoglobin >12gm/dl non anemic. Results: Majority patients were belonged to age group 61-70 years in both groups, 7(33.3%) in group I (Anemic) and 10(33.3%) in group II (Non-Anemic). 25(75.76%) had complications developed in group I and 14(42.4%) in group II, which was significantly associated with between two groups (p<0.05). A subject with Hb (≤12 mg/dl) compared to Hb (>12 mg/dl) was 16.289 (95% CI 1.889 to 98.445%) times more likely to have developed complications. Which was statistically significant (p<0.05). A subject with ejection fraction (<45%) compared to ejection fraction (>45%) was 8.221 (95% CI 1.107 to 61.043%) times more likely to have developed complications. Recurrent angina was found 13(61.9%) in group I and 5(15.2%) in group II. Conclusion: Major adverse cardiovascular events in individuals with all ACS types are strongly and independently predicted by anaemia. Low haemoglobin ACS patients have a worse clinical prognosis
Acute coronary syndrome (ACS) represents a grim challenge to global cardiovascular health. An estimated 129 million disability-adjusted life years (DALYs) and seven million deaths are annually attributed to ischemic heart disease globally.1 The term ACS encompasses ST-elevation myocardial infarction (STEMI) and non-ST elevation ACS (NSTE-ACS), which encompasses non-ST elevation myocardial infarction (NSTEMI) and unstable angina (UA). Approximately two thirds of ACS presentations are with NSTE-ACS and the remainders are STEMI.2
Anemia in the setting of acute coronary syndrome (ACS) has an established adverse prognostic value. Its impact on outcome appears to be independent of underlying causative factors.3 The incidence of coronary heart disease (CHD) is high and ranks number 2 in frequency as the cause of death in official vital statistics after cancer in developed countries. Worldwide 30 % of all death can be attributed to cardio vascular disease of which more than half are caused by CHD. Hemoglobin level connected with coronary artery disease. Anemia is an independent risk factor for cardiovascular disease out come in the atherosclerosis risk in community cohort.4
Reduction in hemoglobin concentration may compromise oxygen supply to infarcted or ischaemic myocardium, which may promote arrhythmias, worsen hypotension and increase infarct size. Two prior studies in patients with AMI treated conservatively suggest that early and late mortality may be increased in patients presenting with anaemia.
Prospective, Observational Study was carried out in the Department of Cardiology, Northeast Medical College, Sylhet, Bangladesh. During June 2023 to May 2024. Total 66 patients who were admitted with acute coronary syndromes with anaemic and non anaemic were taken as study population. Patients of both sexes with ST-Segment Elevation Myocardial Infarction, Non ST-Segment Elevation Myocardial Infarction and patients with unstable angina were included in this study. Patients with history of prior myocardial infarction, active or recent internal bleeding, known bleeding diathesis, significant liver or renal disease (typically a creatinine ≥2.0mg/dl) and patient with active Cancer were excluded in this study. All patients admitted in the department of Cardiology of National Heart Foundation Hospital & Research Institute, Dhaka fulfilling the criteria for inclusion was considered. Meticulous history was taken regarding symptoms (chest pain or dyspnoea) and detailed clinical examination was performed in each patient. Demographic data such as age, sex, height (cm), weight (kg), were noted. Risk factors were recorded for ACS patients. Patients were stratified into 2 groups according to hemoglobin. In hospital outcome were noted in both groups. Statistical analyses were carried out by using the Statistical Package for Social Sciences version 23.0 for Windows (SPSS Inc., Chicago, Illinois, USA). The mean values were calculated for continuous variables. The quantitative observations were indicated by frequencies and percentages. Chi-Square test was used to analyze the categorical variables, shown with cross tabulation. Student t-test was used for continuous variables. Multivariable analysis to prediction of clinical outcome (Developed complications) in acute coronary syndromes patients. P values <0.05 was considered as statistically significant.
Table 1 shows that majority patients were belonged to age group 61-70 years in both groups, 11(33.3%) in group I anemic and 10(30.3%) in group II Non-Anemic. The mean age was found 55.85±10.93 years in group I and 56.90±11.02 years in group II. Males were predominant in both groups, 24(72.73%) in group I and 27(90.9%) in group II. Table 2 shows that smoker was found 19(57.58%) in group I and 18(54.5%) in group II. Hypertension was 9(27.27%) and 14(42.4%) in group I and group II respectively. Diabetes mellitus was 16(48.48%) in group I and 08(30.3%) in group II (p<0.05). Dyslipidemia was 9(27.3%) and 9(27.3%) in group I and group II respectively. Family history of IHD was 16(47.6%) in group I and 9(24.2%) in group II. The difference was not statistically significant (p>0.05) between two groups. Table 3 shows that 25(75.76%) had complications developed in group I and 14(42.4%) in group II, which was significantly associated with between two groups (p<0.05). A subject with ejection fraction (<45%) compared to ejection fraction (>45%) was 8.221 (95% CI 1.107 to 61.043%) times more likely to have developed complications. A subject with anemia compared to non- anemia was 16.289 (95% CI 1.889 to 98.445%) times more likely to have developed complications. Which was statistically significant (p<0.05). However, other parameters were not significantly associated with clinical outcome (developed complications) (Table-4).
Table 1: Demographic characteristics of the study patients (n=66)
Parameters |
Group I (n=33) |
Group II (n=33) |
p value |
||
n |
% |
n |
% |
||
Age (years) |
|
|
|
|
|
31-40 |
5 |
15.15 |
3 |
9.1 |
|
41-50 |
6 |
18.18 |
9 |
27.3 |
|
51-60 |
9 |
27.27 |
8 |
24.2 |
|
61-70 |
11 |
33.33 |
10 |
30.3 |
|
>70 |
2 |
6.06 |
3 |
9.1 |
|
Mean±SD |
55.85±10.93 |
56.90±11.02 |
0.733ns |
||
Sex |
|
|
|
|
|
Male |
24 |
72.73 |
27 |
90.9 |
0.25ns |
Female |
09 |
27.27 |
05 |
9.1 |
In group-I Anemic
In group-II Non Anemic
Table 2: Distribution of the study patients by risk factors (n=66)
Risk factors |
Group I (n=33) |
Group II (n=33) |
P value |
||
n |
% |
n |
% |
||
Smoker |
19 |
57.58 |
18 |
54.5 |
0.80ns |
Smokeless Tobacco |
6 |
18.18 |
4 |
12.1 |
0.49ns |
Hypertension |
9 |
27.27 |
14 |
42.4 |
0.19ns |
Diabetes mellitus |
16 |
48.48 |
08 |
30.3 |
0.04s |
Dyslipidemia |
9 |
27.27 |
9 |
27.3 |
0.1ns |
Family history of IHD |
16 |
48.48 |
9 |
24.2 |
0.07s |
ns=not significant
P value reached from Chi square test
Table 3: Distribution of the study patients by clinical outcome (n=66)
Clinical outcome |
Group I (n=33) |
Group II (n=33) |
P value |
||
n |
% |
n |
% |
||
Complications developed |
25 |
75.76 |
14 |
42.4 |
0.005s |
Not developed |
8 |
24.24 |
19 |
57.6 |
s=significant
P value reached from Chi square test
Table 4: Multivariable analysis to prediction of clinical outcome (Developed complications) in acute coronary syndromes patients
Parameters |
Odds ratio |
95% CI (Lower-upper) |
p value |
Age (>50 years) |
0.478 |
0.076-3.017 |
0.433ns |
Sex (Male) |
3.912 |
0.214-71.653 |
0.358ns |
Smoker |
0.177 |
0.022-1.448 |
0.106ns |
Hypertension |
2.719 |
0.297-24.938 |
0.376ns |
Diabetes |
6.328 |
0.818-48.976 |
0.077ns |
Dyslipidemia |
0.439 |
0.056-3.540 |
0.434ns |
Family history of IHD |
0.532 |
0.061-4.618 |
0.567ns |
BMI (≥25 kg/m2) |
0.214 |
0.017-2.634 |
0.229ns |
Serum creatinine (>1.4 mg/dl) |
0.563 |
0.073-4.331 |
0.581ns |
Ejection fraction (<45%) |
8.221 |
1.107-61.043 |
0.039s |
STEMI |
0.221 |
0.034-1.451 |
0.116ns |
NSEMI |
2.981 |
0.821-10.818 |
0.097ns |
Hb (<12 mg/dl) |
16.289 |
1.889-98.445 |
0.011s |
s=significant; ns=not significant
Multivariate logistic regression analysis was done
In this study observed that majority patients were belonged to age group 61-70 years in both groups, 11(33.3%) in group I anemic and 10(30.3%) in group II Non-Anemic. The mean age was found 55.85±10.93 years in group I and 56.90±11.02 years in group II. Males were predominant in both groups, 24(72.73%) in group I and 27(90.9%) in group II. Brener et al.5 reported the mean age was found 66.4±11.3 years in anemia group and 61.3±11.6 years in non anemia group. Male was found 68.7% in anemia group and 72.1% in non anemia group. Wester et al.6 reported median age was found 74 years in anaemia group and 67 years in non anaemia group. Females were found 29.5% in anaemia group and 25.9% in non anaemia group. Grech and Ramsdali7 (2003) found the mean age of the ACS patients were 53.60±8.5 in Bangladeshi population. Gandotta and Miller8 found the mean age of ACS patients were 53.2±10.6 years in Bangladeshi population which supported the finding of present study.
In this study observed that smoker was found 19(57.58%) in group I and 18(54.5%) in group II. Hypertension was 9(27.27%) and 14(42.4%) in group I and group II respectively. Diabetes mellitus was 16(48.48%) in group I and 08(30.3%) in group II (p<0.05). Dyslipidemia was 9(27.3%) and 9(27.3%) in group I and group II respectively. Family history of IHD was 16(47.6%) in group I and 9(24.2%) in group II. The difference was not statistically significant (p>0.05) between two groups. Brener et al.5 reported diabetes mellitus was found 38.5% in anemia group and 22.6% in non anaemia group. Current cigarette smoker was 19.5% and 35.0% in anaemia and non anaemia group. Hypertension was 75.9% in anaemia group and 61.8% in non anaemia group. Hyperlipidemia was 64.0% and 52.3% in anaemia and non anaemia group respectively. Wester et al.6 reported current smoker was found 19.1% in anaemia group and 25.7% in non anaemia group. Hypertension was 60.3% and 50.4% in anaemia and non anaemia group respectively. Diabetes mellitus was 25.0% in anaemia group and 15.0% in non anaemia group. The difference was statistically significant (p<0.05) between two groups. Lee et al.9 showed diabetes was found 46.0% in Hb 10-12 g/l group and 29.0% in Hb >12 g/l group. History of hypertension was 91.0% in Hb 10-12 g/l group and 84.0% in Hb >12 g/l group. Nikolsky et al.10 current smoking was found 29.2% in patients with anemia group and 45.2% in patients without anemia group. Diabetes mellitus was 21.5% and 15.8% in patients with anemia and without anemia group. Hypertension was 56.5% in patients with anemia group and 46.7% in patients without anemia group. Hyperlipidemia was 39.2% and 37.9% in patients with anemia and without anemia group respectively.
In this study showed subjects with ejection fraction (<45%) compared to ejection fraction (>45%) was 8.221 (95% CI 1.107 to 61.043%) times more likely to have developed complications. A subject with Hb (<2 mg/dl) compared to Hb (>12 mg/dl) was 16.289 (95% CI 1.889 to 98.445%) times more likely to have developed complications. Which was statistically significant (p<0.05). However, other parameters were not significantly associated with clinical outcome (Developed complications). Ezekowitz et al.11 reported clinical and demographic variables, patients with anemia were more likely to be older (odds ratio [OR] 1.01 per year) and female (OR 1.2 [95% confidence interval 1.1 to 1.3]) and to have a history of chronic renal insufficiency (OR=3.2 [95% confidence interval 2.8 to 3.6]), or hypertension (OR 1.3 [95% confidence interval 1.2 to 1.5]). Hazard ratios for mortality, adjusting for covariates, were 1.34 (1.24 to 1.46) in anemic patients, and 1.36 (1.23 to 1.50) in those patients with anemia of chronic disease. González-Ferrer et al.12 reported that the multivariate analysis for these prognostic variables, the admission hemoglobin levels and the upper quartile of the fall in hemoglobin were independently associated with cardiogenic shock or allcause mortality, with an OR of 5.4 (95% CI, 1.5-18.8; P=.009) for the fall in hemoglobin and 1.4 (95% CI, 1.1-1.8 for each 1 g/dL below normal concentrations according to World Health Organization criteria; P=.003) for the admission hemoglobin levels. Wu et al13 found that highly statistically significant and independent association between low hemoglobin concentration and adverse cardiovascular outcome among the patient with ACS. Their finding was worsening degrees of anemia were associated with progressively higher rates of hypotension tachycardia and heart failure. Fried and Raw14 found that the patient group with lower hemoglobin concentration on admission more likely suffered from cardiogenic shock, CCF and post infarction angina than the groups with higher hemoglobin level on admission.
Anaemia is a powerful and independent predictor of major adverse cardiovascular events in patients across the spectrum of ACS. ACS patients with low Heamoglobin are associated with adverse clinical outcome. So more critical attention should be given to this group of patients.