European Journal of Cardiovascular Medicine

Cardiovascular diseases remain the leading cause of morbidity and mortality globally, with acute coronary syndrome (ACS) accounting for a substantial portion of these outcomes. In India, the burden of coronary artery disease has risen significantly over the past two decades, particularly among younger populations, highlighting an urgent need to identify modifiable risk factors associated with poor outcomes [1,2].

Metabolic syndrome (MetS), a cluster of cardiovascular risk factors including central obesity, hypertension, dyslipidemia, and insulin resistance, has been strongly linked to the development and progression of atherosclerosis and coronary artery disease [3]. The National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) defines MetS as the presence of three or more of five metabolic abnormalities: elevated waist circumference, triglycerides, blood pressure, fasting glucose, and reduced HDL cholesterol [4].

Numerous international studies have demonstrated that patients with ACS who also meet the criteria for MetS exhibit a higher incidence of multi-vessel coronary artery disease, left ventricular dysfunction, and in-hospital complications [5–7]. The presence of MetS not only exacerbates the pathophysiology of myocardial ischemia but is also associated with increased inflammatory burden and endothelial dysfunction [8].

In the Indian context, where lifestyle-related risk factors are prevalent and metabolic disorders often underdiagnosed, assessing the impact of MetS on ACS presentation and outcomes is particularly important. However, local data on the prevalence of MetS in ACS patients, and the clinical and angiographic differences between those with and without MetS, remain limited.

This study was undertaken to estimate the prevalence of metabolic syndrome in patients presenting with ACS and to compare the demographic characteristics, clinical features, echocardiographic findings, and in-hospital outcomes of patients with and without metabolic syndrome in a tertiary care centre in Western India.

Study Design and Setting

This was a prospective observational study conducted in the Department of Medicine at Pacific Medical College and Hospital, Udaipur, Rajasthan, over an 18-month period from January 2021 to June 2022. The study protocol was approved by the institutional ethics committee, and informed consent was obtained from all participants.

Study Population

A total of 100 patients diagnosed with acute coronary syndrome (ACS), including ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), were consecutively enrolled. The diagnosis of ACS was based on clinical history, electrocardiographic findings, and cardiac biomarkers, as per American Heart Association guidelines.

Inclusion Criteria

• Adults aged ≥18 years with a confirmed diagnosis of ACS (STEMI or NSTEMI).
• Presentation within 72 hours of symptom onset.

Exclusion Criteria

• Patients with pre-existing chronic heart failure or valvular heart disease.
• Chronic inflammatory or autoimmune conditions.
• Those who declined to give consent.

Definition of Metabolic Syndrome

Metabolic syndrome (MetS) was defined according to the revised National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. Patients meeting three or more of the following five conditions were classified as having MetS:

1. Abdominal obesity: Waist circumference >90 cm in men or >80 cm in women.
2. Hypertriglyceridemia: Serum triglycerides ≥150 mg/dL or on treatment.
3. Low HDL cholesterol: <40 mg/dL in men or <50 mg/dL in women.
4. Elevated blood pressure: Systolic BP ≥130 mmHg, diastolic BP ≥85 mmHg, or on antihypertensive treatment.
5. Impaired fasting glucose: Fasting plasma glucose >100 mg/dL or on glucose-lowering medication.

Data Collection and Clinical Evaluation

Baseline demographic details, clinical symptoms, anthropometric parameters, and risk factors such as hypertension, diabetes, family history, and smoking were recorded. Laboratory evaluations included fasting glucose, lipid profile, and cardiac biomarkers. All patients underwent 2D echocardiography to assess left ventricular function and valvular abnormalities. Angiographic and interventional findings were documented where available.

Outcomes Assessed

In-hospital outcomes including percutaneous transluminal coronary angioplasty (PTCA), coronary artery bypass grafting (CABG), and in-hospital mortality were recorded. The prevalence of MetS and its individual components was calculated. Comparative analyses between MetS and non-MetS groups were performed to assess demographic, clinical, and outcome differences.

Statistical Analysis

All data were entered into Microsoft Excel and analyzed using SPSS version 20.0. Descriptive statistics were expressed as mean ± standard deviation for continuous variables and percentages for categorical variables. Intergroup comparisons were performed using the independent sample t-test for continuous variables and the chi-square test or Fisher’s exact test for categorical variables. A p-value <0.05 was considered statistically significant.

Comparison between Patients with and Without Metabolic Syndrome

Among the 100 patients with acute coronary syndrome (ACS), 65 (65%) met the diagnostic criteria for metabolic syndrome (MetS), while 35 (35%) did not. Patients in the MetS group were significantly older, with a mean age of 60.75 ± 10.61 years, compared to 55.63 ± 10.92 years in the non-MetS group (p = 0.022).

There was also a statistically significant difference in gender distribution. Males comprised 76.9% of the MetS group, whereas only 57.1% of the non-MetS group were male (p = 0.040). These findings suggest that older age and male sex are associated with a higher likelihood of metabolic syndrome among patients presenting with ACS.

Clinical Presentation at Admission

The most common presenting symptom among patients with acute coronary syndrome was chest pain, reported by 95% of the cohort. Shortness of breath was present in 75% of patients, while sweating occurred in 66%. Less frequently, vomiting and palpitations were noted in 24% and 10% of patients, respectively. These findings reflect the typical clinical profile of ACS in a mixed population of STEMI and NSTEMI cases.

Prevalence of Metabolic Syndrome Components

Among the 100 patients with acute coronary syndrome, 65% met the criteria for metabolic syndrome based on the NCEP ATP III definition. The most prevalent component was increased waist circumference, present in 66% of patients, followed by elevated triglycerides in 62%. Low HDL cholesterol was observed in 59%, while elevated fasting glucose and high blood pressure were seen in 53% and 51% of patients, respectively. These findings indicate a high burden of cardiometabolic abnormalities in ACS patients, with central obesity and dyslipidemia being the dominant contributors.

Bar chart showing the frequency of each component based on NCEP ATP III criteria. Central obesity and dyslipidemia were the most prevalent abnormalities.

In-Hospital Outcomes

Regarding in-hospital management and outcomes, 49% of patients underwent percutaneous transluminal coronary angioplasty (PTCA), while 6% required coronary artery bypass grafting (CABG). A total of 18% of patients died during hospitalization, reflecting the acute severity of illness, and 82% were discharged following stabilization. These results emphasize the importance of early diagnosis and intervention in acute coronary syndrome, particularly among patients with underlying metabolic syndrome.

In this study, the prevalence of metabolic syndrome (MetS) among patients presenting with acute coronary syndrome (ACS) was found to be 65%, consistent with previous studies that have reported rates between 46% and 69% in similar populations [11–13]. This high prevalence reflects the growing burden of cardiometabolic risk factors in Indian patients presenting with coronary events.

We found that patients with MetS were significantly older than those without, and a larger proportion were male. These trends have been echoed by prior research from Vaidya et al. and Goyal et al., both of whom identified older age and male sex as dominant predictors of metabolic syndrome among ACS patients [11,14].

Central obesity, elevated triglycerides, and low HDL-C were the most prevalent MetS components in our cohort. Similar trends have been described by Misra and colleagues, who emphasized the predominance of abdominal adiposity and dyslipidemia in the Indian metabolic phenotype [15]. The presence of low HDL-C—a particularly common feature in South Asians—was found in nearly 60% of patients, supporting its inclusion as a key diagnostic component in local guidelines [15].

Patients with MetS also had higher rates of diabetes and hypertension—both strongly associated with adverse coronary outcomes. Our findings are in agreement with Singh et al. and Rathod et al., who noted that these comorbidities contribute substantially to the risk and severity of ACS when occurring in the setting of metabolic syndrome [16,17].

Notably, in-hospital mortality was higher in the MetS group (27.7%), compared to 0% in the non-MetS group. These results are consistent with the observations of Fanta et al. and Al Suwaidi et al., both of whom found that MetS is associated with increased in-hospital complications, including heart failure and death, due to its inflammatory and pro-thrombotic burden [18,19].

Our analysis also revealed that the majority of MetS patients had four or more components of the syndrome, suggesting a dose–response relationship between the number of metabolic abnormalities and clinical severity. This finding aligns with the conclusions of Ashok et al., who reported that outcomes worsen as the metabolic load increases [20]. Overall, our findings support the need for early identification of MetS in ACS patients, particularly using simple anthropometric measures such as waist circumference and BMI. Preventive strategies targeting lifestyle, glycemic control, and lipid optimization are vital to reducing both the incidence and severity of coronary events in high-risk populations.

This prospective observational study highlights a strikingly high prevalence of metabolic syndrome among patients with acute coronary syndrome in a tertiary care setting in India. Central obesity, low HDL cholesterol, and elevated triglycerides emerged as the most common metabolic derangements, emphasizing the shifting pattern of cardiovascular risk in South Asian populations.

Patients with metabolic syndrome were significantly older, more likely to be male, and demonstrated a higher incidence of diabetes and hypertension—factors that contributed to increase in-hospital mortality and poorer overall outcomes. The presence of four or more metabolic syndrome components was particularly associated with adverse clinical trajectories.

These findings underscore the urgent need for early identification of metabolic syndrome in all patients at risk of cardiovascular events. Waist circumference, fasting glucose, and lipid profiles should be routinely assessed in individuals presenting with chest pain or coronary risk factors, especially in primary care and emergency settings.

We recommend that cardiology and internal medicine services adopt standardized screening for metabolic syndrome as part of ACS evaluation. Public health policies should also prioritize lifestyle interventions—such as dietary modification, increased physical activity, and smoking cessation—to reduce the burden of cardiometabolic disease.

Further multicentric studies with larger sample sizes and long-term follow-up are warranted to validate these findings and assess the role of targeted metabolic interventions in improving cardiovascular outcomes in high-risk Indian populations.

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