Prognostic significance of baseline plasma C-reactive protein levels in patients with acute coronary syndromes: A retrospective observational study

Rohit Raina; Mayushi Gupta

doi:10.4103/jcpc.jcpc_57_21

ORIGINAL ARTICLE

Year : 2022 | Volume : 11 | Issue : 4 | Page : 86-89

Prognostic significance of baseline plasma C-reactive protein levels in patients with acute coronary syndromes: A retrospective observational study

Rohit Raina¹, Mayushi Gupta²
¹ Department of Internal Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
² Department of Internal Medicine, Acharya Shri Chander College of Medical Sciences, Jammu, Jammu and Kashmir, India

Date of Submission	14-Dec-2021
Date of Decision	29-Nov-2022
Date of Acceptance	06-Dec-2022
Date of Web Publication	21-Jan-2023

Correspondence Address:
MD Rohit Raina
House No 44, Lane 11, Gurah Keran, Barnai Bantalab, Jammu - 181 123, Jammu and Kashmir
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jcpc.jcpc_57_21

Abstract

Objective: The objective of this study is to assess baseline plasma C-reactive protein (CRP) levels in patients with acute coronary syndromes and their significance in prognosis. Materials and Methods: The study was carried out at the department of internal medicine in a tertiary health care center. Fifty patients diagnosed with acute coronary syndromes (ACSs) (ST-elevation acute myocardial infarction (STEMI) or unstable angina (UA)/non-STEMI) were admitted and detailed history, clinical examination, and laboratory tests were done on each patient. All routine blood investigations were carried out along with electrocardiography and echocardiography in all patients. Plasma concentrations of CRP were measured with an ultra-sensitive latex immunoassay before reperfusion, 24 h after admission, and at discharge. Results: A total of 50 patients were taken. Thirty-eight cases were found to be male and the remaining 12 were female, of which 35 were STEMI and 15 were UA/NSTEMI. The maximum prevalence of ACS was observed in the age group of 41–50 years. Among all five presenting symptoms, chest pain was the most prevalent, followed by sweating, breathlessness, vomiting, and giddiness. The major risk factors in ACS include smoking being the most common followed by diabetes and dyslipidemia. In 16 patients, left ventricular failure was recorded, which was the most common complication followed by cardiogenic shock and atrioventricular block. ventricular tachycardia/ventricular fibrillation is recorded in five patients who died, 36 patients with complications, and three patients among 40 patients without complications where CRP levels are ≥0.6 mg/dl. Four patients out of 10 patients who showed CRP levels <0.6 mg/dl are known to have complications. Conclusions: It was concluded that the measurement of plasma CRP levels at the time of admission in patients with suspected coronary artery disease may be helpful in the identification of a group of patients with a high risk of cardiac complications.

Keywords: Acute coronary syndromes, cardiac complications, C-reactive protein, prognosis

How to cite this article:
Raina R, Gupta M. Prognostic significance of baseline plasma C-reactive protein levels in patients with acute coronary syndromes: A retrospective observational study. J Clin Prev Cardiol 2022;11:86-9

How to cite this URL:
Raina R, Gupta M. Prognostic significance of baseline plasma C-reactive protein levels in patients with acute coronary syndromes: A retrospective observational study. J Clin Prev Cardiol [serial online] 2022 [cited 2023 Mar 29];11:86-9. Available from: https://www.jcpconline.org/text.asp?2022/11/4/86/368355

Introduction

Cardiovascular disease is the most common cause of death worldwide accounting for 17.9 million deaths annually.^[1] In an industrialized developed country, there has been a considerable decline in the incidence and prevalence of atherosclerotic coronary artery diseases (CADs) over the past three decades. In contrast, atherosclerotic CADs are appearing as an epidemic in developing countries. Asian Indians have a higher incidence of CADs as compared to all other ethnic groups.^[2] Asian Indians are suffering from more severe and diffuse CADs with a predisposition to younger age having serious complications. Hyperlipidemia, hypertension, diabetes mellitus, and cigarette smoking are the most common risk factors. Other relevant risk factors include insulin resistance syndrome, metabolic syndrome X, lipoprotein (a), atherogenic dyslipidemia phenotype, and some emerging risk factors (homocysteine, tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1), fibrinogen, factor VII, infections, and inflammations) in ethnic Asian Indians. Increasing mortality in Asian Indians could be explained by the fact that they have an underlying genetic susceptibility to lipid metabolism and their lifestyle factors too played a role.

Nowadays, C-reactive protein (CRP) emerged to be an important marker among various novel inflammatory markers. With inflammation, inflammatory cytokines will be released from inflamed tissue. Since inflammation is an important factor in acute myocardial infarction (MI), CRP which is an acute-phase reactant gets synthesized by the liver along with other inflammatory cytokines. In clinical studies, it is shown that infarct size and prognosis depend on circulating levels of CRP in acute MI. CRP levels rise in unstable angina (UA)^[3] and in acute MI.^[4] Despite myocardial cell injury, the concentrations of CRP and serum amyloid A are high in UA.^[5] The studies also reported that poor prognosis in UA is related to higher concentrations of CRP (>3.0 mg/l) at the time of hospital admission. The recurrence of cardiovascular events and death are related to high CRP levels independently.^[6] Apart from being, the marker of generalized inflammation CRP also participates in both atherogenesis^[7] and atheromatous plaque disruption.^[8] Thus, CRP marks underlying coronary inflammation as well as the extent of myocardial necrosis.

Materials and Methods

The present study has been carried out in the department of medicine in a tertiary health center. Patients who have been diagnosed with acute coronary syndromes (ACSs) (ST-elevation acute MI [STEMI] or UA/non-STEMI [NSTEMI]) and admitted to the medical intensive care unit were the subjects. The sample consists of 50 cases of ACSs. Proper informed consent was taken from each patient/relative and studied according to pro forma.

Inclusion criteria

Fifty patients were admitted to Intensive Cardaic Care Unit (ICCU) with the diagnosis of:

STEMI
UA/NSTEMI

Diagnosis of ACSs was made by history, physical examination, and electrocardiogram.

Exclusion criteria

All cases of stable angina
Presence of infectious diseases
Patients with malignant diseases
Recent major trauma
Recent major surgery
Patients on immunosuppressive drugs
Osteoarthritis, rheumatoid arthritis, psoriatic arthritis, gout, etc.
Immunological diseases
Patients on statins, fibrates, niacin, and aspirin
Patients taking estrogen and progesterone pills.

A detailed history was taken. A thorough clinical examination was done and laboratory tests were used to exclude the abovementioned conditions. Along with routine blood investigations, electrocardiography and echocardiography were done in all patients. All patients were followed up and observed for the development of complications. The CRP assay was performed by latex-enhanced nephelometry.

Study data were recorded with the help of a structured schedule (case report form) and entered for tabulation in a Microsoft Excel sheet. Statistical Package for the Social Services version 18.0 (IBM SPSS Inc., Chicago IL) was used for statistical data analysis. The data were calculated by the frequency, percentage, and mean ± standard deviation, and the level of statistical significance was calculated with a significant P < 0.05.

Results

In the present study of a total of 50 patients, 38 (76.0%) cases were male and 12 (24.0%) cases were female [Figure 1]. This data showed male gender preponderance which showed that the male gender is more susceptible to cardiovascular events. The maximum prevalence of ACS (36.0%) was reported in the age group between 41 and 50 years which was followed by 51–60 years (24.0%) and 61–70 years (22.0%) age groups, whereas the minimum prevalence (8.0%) was reported in age group >70 years. Among all the cases, the minimum age was 30 years and the maximum age was 90 years. There were 35 STEMI patients, of which 30 were male and five female out of 50 cases in the present study, and eight patients were male and seven were female among the total 16 cases of UA/NSTEMI.

Figure 1: Distribution of acute coronary syndromes among different age groups and sex

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Out of five presenting symptoms considered in the study, chest pain was the most prevalent symptom accounting for n = 45, (90.0%) which was followed by sweating n = 33 (64.0%) patients, breathlessness n = 18 (36.0%), vomiting n = 11 (22.0%), and giddiness n = 5 (10.0%) patients [Figure 2].

Figure 2: Distribution of patients according to symptoms and risk factors

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In the present study, the percentage-wise distribution of various major risk factors in overall ACSs is presented in [Figure 2]. Smoking was found to be the most common risk factor accounting for n = 35 (70.0%) patients followed by diabetes and dyslipidemia. Thirty-five (87.5%) were smokers among the 40 male patients who suffered from ACSs. Thus, smoking was directly related to ischemic heart disease (IHD). The next common risk factors were diabetes mellitus (32%) and lipid abnormalities (50%) observed in the present study. Triglycerides were raised and high-density lipoprotein was observed to be low in 15 (30%) patients. Low-density lipoprotein (LDL) was high in 10 (20%) patients, whereas 5 (10%) patients showed high total cholesterol levels. Erythrocyte sedimentation rate was found to be high in n = 32 (64%) patients where 26 were male and six were female, raised leukocyte count was observed in n = 15 (30%) patients, and raised blood glucose levels were found in n = 16 (30%) patients with diabetes mellitus patients.

Thirty-five had STEMI and 15 had UA/NSTEMI among 50 patients with ACSs. Extensive anterior wall involvement was the most common type (15 patients) among 35 STEMI patients, followed by anteroseptal, anterolateral, and inferior wall involvement.

The data regarding the complications are presented in [Figure 3]. A perusal of the data revealed that 32% (n = 16) patients showed left ventricular failure as the most common complication which was recorded followed by cardiogenic shock in 22% (n = 11), atrioventricular (AV) block in 12% (n = 6), and two patients had Left Bundle Branch Block (LBBB). Out of 50 patients, 5 (10%) patients had ventricular tachycardia/ventricular fibrillation and died. In general, n = 40 (80%) patients suffered from complications, whereas n = 10 (20%) patients did not show any complications. Of the five patients with AV blocks, three patients showed 2:1 second-degree AV block, one patient had the Wenckebach phenomenon and the remaining two patients had complete heart block.

Figure 3: Distribution of complications among patients

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CRPs estimation at a level >0.6 mg/dl is detected as positive, whereas <0.6 mg/dl as negative according to the qualitative method. The data regarding the CRP levels of the patients are presented in [Table 1]. The data revealed that CRP level of ≥0.6 mg/dl, 36 patients showed the complication, whereas three patients were without complications among a total of 40 patients. Similarly, four patients among 10 patients with CRP levels of <0.6 showed complications. This indicates that patients with high serum C-reactive levels at admission are vulnerable to complications.

Table 1: C-reactive protein in patients with or without complications

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Discussion

In the present study, the percentage ratio of 76:24 was observed in males and females, respectively, showing male preponderance, suggesting that males are more susceptible to cardiovascular events. In the age group of 41–50 years, there was the maximum number of cases, i.e., 36% (n = 18). Sharma et al.^[9] also reported similar results to our study where they found the mean age of the patients as 36.14 years, of which the maximum was in the age group of 41–50 years, and the Male: Female ratio was found to be 8:1. Singh et al.^[10] observed in their study that the highest number of cases was among 51–60 years (34.21%) and the mean age of survived cases was 56.75 ± 10.47. Two other studies from Pakistan and Chennai study reported similar findings. In the present study, the percentage of males was 76.58%, with a male: female ratio of 3.3:1. The maximum anterior wall MI occurred among males (82%) with a male: female ratio of 4.5:1 was noted in the South Indian study. In the North Bengal study, a higher prevalence of CAD was noted among males. In a North India study, it was shown that among STEMI cases, males were likely to be affected among all age groups.^[10]

In the present study, inflammation and probably myocardial damage were observed in 30 males and five females among 35 patients with STEMI (n = 35) and 15 cases were UA/NSTEMI which signifies a greater degree of as well. Xavier et al.^[11] found that a higher rate of STEMI (61%) is present in Indian patients with ACS as compared to patients in high-income countries (15%–25%). India shows the highest burden of ACS in the world and pro contemporary data is shown on 20,468 patients from 89 centers from 10 regions and 50 cities in India presented in the CREATE registry.

The major risk factor in ACSs in the present study is smoking which accounts for 36 (72.0%) patients followed by diabetes and dyslipidemias. Thus, smoking was strongly associated with IHD. Similar reports were found in the study conducted by Sharma et al.^[7] who found smoking, dyslipidemia, and diabetes as major risk factors. As reported by other International Research Groups, smoking or smokeless tobacco is a risk factor for STEMI. Smokers are also reported to have a significantly higher prevalence of IHD than nonsmokers according to a North Bengal study. Other studies conducted on the Indian population also found smoking to be an important risk factor for CAD.^[10] There are data regarding high-sensitivity CRP (hs-CRP) concentrations and the risk of heart failure in patients with ACS. Several studies reported that high concentrations of hs-CRP episodes of heart failure were present among elderly patients with no known cardiovascular disease.^[12] A relationship between hs-CRP and heart failure in patients with STEMI,^[13] or an association between hs-CRP and heart failure was also reported.^[14] In the present study, diabetes mellitus was recorded in 32.0% of patients followed by lipid abnormalities (54%). Hazar^[15] has also concluded that DM patients are more prone to the development of cardiovascular disease. In the present study, chest pain, sweating, breathlessness, vomiting, and giddiness were the five presenting symptoms. Chest pain among these was found to be most prevalent which was also revealed in earlier studies conducted by Cervelline and Rastelli.^[16]

In the present study, a CRP level ≥0.6 mg/dl was found in 36 patients showing complications. Three patients were without complications. Among all 39 patients, 10 patients had a CRP level of < 0.6 mg/dL. Statistical differences between the two groups were found to be significant (P < 0.0001). Further, with the development of heart failure, CRP tends to increase playing a significant role. The risk of mechanical consequences and complications of ischemic injury increases with the intensity of the inflammatory response. Increased concentrations of CRP possess a high risk of developing congenital heart failure after ACS and prompt regular screening and more aggressive therapy is required and adverse remodeling can be targeted for prevention by the development of novel therapies. On admission, independent prognostic information was provided by the assessment of CRP and thereby the ability to identify patients with the highest risk of death and heart failure was improved. A study by Mach et al.^[17] showed that the CRP concentration at the time of admission was significantly higher among patients with acute IHD, whereas patients with UA showed low CRP levels. Karki et al.^[18] reported that significantly high hs-CRP levels of >5 mg/L were present and thus hs-CRP is a useful tool for predicting mortality during the hospital stay and at 6 weeks. In the GRACE registry, 12% of STEMI patients, 13% of NSTEMI, and 8% of UA patients were expected to die within 6 months of symptom onset.

Many studies revealed the prognostic significance of hs-CRP. Most of the studies were done in stable CAD. The JUPITER trial which was carried out in participants with CRP levels >2 mg/L found that hs-CRP and LDL levels declined in the patients after rosuvastatin treatment and thus finally, leading to a decrease in the cardiovascular outcomes. The present study showed that the increase in the age of patients has a positive correlation with the increase in CRP level. Liuzzo et al.^[5] demonstrated that CRP elevation had a poor outcome in patients with UA with no myocardial damage as there was no rise in troponin T levels.

Conclusions

Patients with high levels of CRP need aggressive cardiac management and close monitoring after discharge. In patients with suspected CAD, the measurement of plasma CRP levels should be done at the time of admission. CRP levels may be related to inflammatory processes associated with multiple plaque ruptures or infarct expansion in patients with ACSs.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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