Acute Coronary Syndrome (ACS) is a significant global health burden, contributing to high morbidity and mortality rates among cardiovascular diseases (1). It encompasses a spectrum of conditions, including unstable angina (UA) and myocardial infarction (MI), which result from atherosclerotic plaque rupture and subsequent thrombosis leading to myocardial ischemia (2,3). Despite advancements in diagnostic and therapeutic strategies, risk stratification remains a crucial component of ACS management to improve patient outcomes.

Inflammation plays a central role in the pathophysiology of ACS, and biomarkers reflecting inflammatory activity have gained attention in risk assessment (4). Among them, C-reactive protein (CRP), an acute-phase reactant produced by the liver in response to systemic inflammation, has been widely studied for its prognostic significance in cardiovascular diseases (5,6). Elevated CRP levels have been associated with endothelial dysfunction, plaque instability, and increased thrombotic potential, contributing to adverse cardiovascular events (7,8).

Several studies have demonstrated a direct correlation between high CRP levels and worse clinical outcomes in ACS patients, including increased rates of myocardial infarction, recurrent ischemic events, heart failure, and mortality (9,10). The American Heart Association (AHA) and the Centers for Disease Control and Prevention (CDC) have recognized CRP as a potential marker for cardiovascular risk stratification (11). However, its routine application in ACS prognosis remains debated, necessitating further clinical evaluation.

This study aims to assess the prognostic value of CRP levels in patients presenting with ACS, comparing their correlation with in-hospital complications, length of hospital stay, and mortality. By evaluating CRP as a potential predictor of adverse outcomes, this study seeks to contribute to more effective risk stratification and management strategies for ACS patients.

Study Design and Setting

This prospective observational study was conducted in the Cardiology Department of a tertiary care hospital over a period of six months. Ethical approval was obtained from the institutional ethics committee, and informed consent was collected from all participants before enrollment.

Study Population

A total of 100 patients diagnosed with acute coronary syndrome (ACS) were included in the study. The patients were categorized into two groups: unstable angina (UA) (n=50) and myocardial infarction (MI) (n=50), based on clinical presentation, electrocardiographic (ECG) findings, and cardiac biomarker levels. Patients with chronic inflammatory diseases, infections, malignancies, or prior cardiovascular events within six months were excluded.

Data Collection and CRP Measurement

Blood samples were collected from each patient at the time of hospital admission. Serum C-reactive protein (CRP) levels were measured using a high-sensitivity CRP (hs-CRP) assay through an immunoturbidimetric method. Based on CRP levels, patients were categorized into three groups:

• Low CRP: <3 mg/L
• Moderate CRP: 3–10 mg/L
• High CRP: >10 mg/L

Clinical and Outcome Assessment

All patients underwent a comprehensive clinical evaluation, including ECG, echocardiography, and cardiac enzyme analysis. The primary outcomes assessed were:

• Incidence of major adverse cardiac events (MACE), including recurrent ischemia, heart failure, arrhythmias, and mortality
• Length of hospital stay (≤7 days or >7 days)
• Need for invasive interventions, such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)

Statistical Analysis

Data analysis was performed using SPSS software (version 25.0). Continuous variables were presented as mean ± standard deviation (SD) and compared using the Student’s t-test. Categorical variables were expressed as percentages and analyzed using the Chi-square test. A p-value of <0.05 was considered statistically significant..

Baseline Characteristics

The study included 100 patients diagnosed with acute coronary syndrome (ACS), comprising 50 cases of unstable angina (UA) and 50 cases of myocardial infarction (MI). The mean age of the participants was 58.4 ± 10.2 years, with 65% being male and 35% female. Hypertension and diabetes were the most prevalent comorbidities, observed in 60% and 45% of patients, respectively. Smoking history was noted in 40% of the study population. The baseline characteristics of the study groups are summarized in Table 1.

Serum CRP Levels and ACS Subtypes

The mean CRP level was significantly higher in MI patients (12.5 ± 4.3 mg/L) compared to those with UA (6.8 ± 2.7 mg/L, p<0.01). Among MI patients, 70% had CRP levels >10 mg/L, while only 30% of UA patients exhibited such levels (Table 2).

Association of CRP with Clinical Outcomes

A significant correlation was observed between elevated CRP levels and adverse clinical outcomes. The incidence of major adverse cardiac events (MACE) was highest in the high CRP group (>10 mg/L), with 65% experiencing complications such as recurrent ischemia, heart failure, or arrhythmias, compared to 25% in the moderate CRP group and 10% in the low CRP group (Table 3).

Length of Hospital Stay

Patients with higher CRP levels had a longer duration of hospitalization. Among those with CRP levels >10 mg/L, 65% had hospital stays exceeding 7 days, whereas only 30% of the moderate CRP group and 10% of the low CRP group required extended hospitalization (Table 4).

Mortality Rates

The overall mortality rate was 8%, with all deaths occurring in the high CRP group. No mortality was recorded in patients with CRP levels below 10 mg/L (Table 5).

Tables

Table 1: Baseline Characteristics of Study Population

Table 2: CRP Levels in ACS Patients

Table 3: Association of CRP with MACE

Table 4: Length of Hospital Stay Based on CRP Levels

Table 5: CRP Levels and Mortality Rates

These findings suggest that elevated CRP levels are strongly associated with increased risk of adverse outcomes, prolonged hospital stay, and higher mortality rates in ACS patients

C-reactive protein (CRP) has been increasingly recognized as an important biomarker in assessing the prognosis of acute coronary syndrome (ACS) patients. In this study, we observed a significant correlation between elevated CRP levels and adverse clinical outcomes, including major adverse cardiac events (MACE), prolonged hospitalization, and increased mortality. These findings support previous research indicating the role of systemic inflammation in the pathogenesis and progression of ACS (1,2).

Inflammation plays a central role in atherosclerosis, plaque instability, and subsequent thrombotic events (3). CRP, an acute-phase reactant produced by the liver in response to interleukin-6 (IL-6) stimulation, has been linked to endothelial dysfunction, increased platelet activation, and enhanced prothrombotic activity (4,5). The significantly higher CRP levels observed in myocardial infarction (MI) patients compared to those with unstable angina (UA) in our study align with previous findings demonstrating that CRP levels rise proportionally with the severity of myocardial damage (6).

Several studies have highlighted the predictive value of CRP in determining the likelihood of MACE in ACS patients (7,8). Our study found that 65% of patients with CRP levels >10 mg/L experienced MACE, while only 10% of those with CRP levels <3 mg/L had such complications. This supports the hypothesis that CRP is not merely a marker of inflammation but an active participant in vascular injury, contributing to plaque rupture and progression of coronary events (9).

Prolonged hospital stays were significantly associated with higher CRP levels in our study. Among patients with CRP >10 mg/L, 65% had hospitalization periods exceeding seven days, whereas only 10% of the low CRP group required extended care. Similar trends have been reported in previous studies, where elevated CRP levels were linked to increased rates of recurrent ischemic episodes, heart failure, and need for revascularization (10,11). Elevated CRP may indicate a persistent inflammatory response, leading to delayed recovery and a higher risk of secondary complications (12).

Mortality risk was notably higher in patients with elevated CRP. In our study, all recorded deaths occurred in the high CRP group, with a mortality rate of 8%. Previous research has demonstrated a direct association between increased CRP levels and higher short-term and long-term mortality in ACS patients (13). Elevated CRP has been found to independently predict mortality even after adjusting for traditional risk factors, such as age, diabetes, and left ventricular dysfunction (14).

Despite the strong association between CRP levels and adverse outcomes, routine CRP measurement in ACS patients remains a topic of debate. While some guidelines suggest its use as an adjunct to traditional risk assessment tools, others emphasize the need for further large-scale clinical trials to validate its prognostic utility (15). Future studies should focus on integrating CRP into multi-biomarker models for enhanced risk stratification and personalized treatment strategies.

This study highlights the significant prognostic value of C-reactive protein (CRP) in acute coronary syndrome (ACS). Elevated CRP levels were strongly associated with increased incidence of major adverse cardiac events, prolonged hospital stay, and higher mortality rates. These findings reinforce the role of inflammation in the progression of ACS and suggest that CRP can serve as a useful biomarker for risk stratification. Integrating CRP assessment into routine clinical practice may improve early identification of high-risk patients and aid in optimizing treatment strategies. Further large-scale studies are needed to validate these results and explore potential therapeutic interventions targeting inflammation in ACS.

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