Acute coronary syndrome includes group of diseases in which blood flow to the heart is reduced. It includes ST-elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI), and unstable angina.^[1] India has the highest rate of cardiovascular disease when compared to the other countries, with a prevalence rate of 1.6% to 7.4% for rural and 1% to 13.2% for urban population. According to various literature review done on STEMI in young patients across different countries, the common risk factors include smoking, alcohol, history of ischemic heart disease, the most common angiographic finding being single vessel disese.^[2-10]

Need for the Study

To identify the risk factors for STEMI among young patients in order to implement aggressive preventive measures to reduce the incidence of the disease among young patients which can improve their quality of life. Clinical presentation and outcomes among young patients with STEMI differs a lot from the older population so a deeper understanding is needed to develop sensitive approach to mitigate the burden of the disease which eventually contributes to improved health outcomes among young patients and decreases mortality among them.

Objectives

• To observe the clinical presentation among young patients presenting with STEMI.
• To determine risk factors among young patients with STEMI
• To observe the angiographic findings among young patients with STEMI
• To observe the outcome among young patients presenting with STEMI post PTCA

A multicentric observational study by Oadi N Shrateh et al, on acute coronary syndrome in young patients in 2024 was conducted among 468 participants diagnosed with acute coronary syndrome between the age of 18-55 years to assess demographic characteristics, clinical presentation, risk factors, treatment factors and outcomes. Where, the majority of patients were male, the most common risk factors were smoking, hypertension, diabetes and family history of coronary artery disease and percutaneous coronary intervention was the main treatment strategy. Thus, concluding that these risk factors can be aimed at to reduce the burden of the disease among the target population.^[2]

Jagannaathan Murugan et al, conducted a cross sectional retrospective study between July 2021-2022 at tertiary care hospital in Chennai on characteristics and treatment analysis of acute coronary syndrome among 198 young patients (age<40 years). Where 57% of the patients had no risk factors, 44% had ST-elevation MI, 48% being single vessel disease thus concluding the need to identify the risk factors in young patients for aggressive preventive measures. Statins and antiplatelet medications made up the majority of patients medical management.^[3]

According to a retrospective study conducted from 2019-2021 by Ming-Ting Liang et al, on clinical risk factors and outcomes among 701 patients with acute ST-elevation myocardial infarction, 108 were aged <45 years and these younger group included more males, smokers, alcoholic, family history of ischemic heart disease, high low density lipoprotein, low high density lipoprotein and the culprit vessel in 60% of young patients being left anterior descending artery.^[4]

In an observational  study done by Yunjuan Sun et al, between 2013 – 2015, 549 patients who suffered with STEMI were divided into 2 groups that is, young patients with age < 50 years and non- young group with age > 50 years to compare clinical features, angiographic findings and clinical outcomes. Where, 131 were young patients associated with male, smoking, Killip class 1 on admission, lower level of N-terminal pro B type natriuretric peptide, high level of triglyceride and low level of high density lipoprotein with intracoronary thrombus and single vessel lesion and one death among them out of 28 deaths. Thus concluding low risk of death among younger group during hospitalization.^[5]

Among 2,13,297 patients with acute MI who underwent primary percutaneous coronary intervention, a retrospective study was conducted by Hirohiko Ando et al, between 2014 to 2018 in japan, on clinical presentation and in hospital outcomes of acute myocardial infarction in young patients, where 11.2% were < 50 years including high numbers of men, smokers, had dyslipidemia, and single vessel disease. Also young age was associated with higher rate of presentation with cardiopulmonary arrest (CPA) thus concluding higher risk of CPA among young patients therefore highlighting the importance of prevention strategies.^[6]

In 2015-2019, a retrospective study done in 2 centers by Bektas Murat et al, showed 212 patients aged 18-40 years with STEMI who had underwent reperfusion therapy among whom gender difference was compared. Chest pain was the most common symptom between both the genders and anterior wall MI was the most common type of MI and higher in women, with left anterior descending artery being the most common coronary artery involved.^[7]

A retrospective study conducted between 2014 and 2017 by Wojchiech Zasada et al, on acute MI in young patients (age<40 years), where, MI was more among men with higher body weight and smokers. The most common artery involved being left anterior descending artery, with an increase in cases among young patients from 1.20% in 2014 to 1.43% in 2017.^[8]

According to a retrospective analysis in multiethnic Asian population conducted from 2015 to 2019 by Benjamin WL Tung et al, on characteristics and outcomes among 1818 patients with STEMI who underwent PCI, 25.6% of patients were <50 years old, where the young patients were more likely to be male, smokers, with history of IHD and had lower one year mortality.^[9]

A cohort study was conducted in Tamilnadu between 2012 and 2014 by Thomas alexander et al, on acute STEMI in young compared with older patients. Where, among 2420 patients, where patients were divided into 2 groups: < 45 years and > 45 years. 92.5% of these young STEMI were males with smoking being the most common risk factor. These patients most commonly presented with single vessel disease, and left anterior descending coronary artery being most commonly involved with higher mortality among female patients.^[10]

Study Design

A retrospective study design.

Duration of the Study

From May 2023 to May 2024.

Source of Data

Patients admitted in department of cardiology, Shridevi institute of medical sciences and research hospital, Tumkur.

Inclusion Criteria

• All genders
• Age : 18-45 years
• Diagnosed with STEMI
• Underwent percutaneous transluminal coronary angioplasty (PTCA).

Exclusion Criteria

• Past history of ACS

Sampling Method

Simple Random Sampling Method

Sample Size

The sample size is calculated using a study conducted in India by Murugan J, et al.^[3] in 2023. In this study shows that the India has one of the highest rates of cardiovascular disease (CVD) in the world, with prevalence rates was 3.3 in both rural and urban populations. At a 95% confidence level and an absolute allowable error of 5%. The sample size was calculating using below formula,

Sample Size (n) =  =  = 49.04

10% non-response rate = 4.90.

Total sample size (n) = 49.04 + 4.90 = 53.94 ≈ 54 participants.

Where,

• q = 1-p
• Z (1- ∝/2)^2= Is standard normal variate (at 10% type I error (p<0.05) it is 1.645 and 1% type I error (p<0.01) it is 2.58). As in majority of studies P values are considered significance below 0.05 hence 1.645 is used in formula.
• P = Expected prevalence in population based on previous studies or pilot studies.
• d = Absolute error or precision.
• Sample size (n) = 54.
• Therefore, at least 54 suspected samples should be included in the study.

METHODOLOGY

• We included patients <45 years who  arrived to emergency care, diagnosed with ACS-STEMI, that is, according to The American College of Cardiology, American Heart Association, European Society of Cardiology, and the World Heart Federation committee the following is the ECG criteria for ST-elevation myocardial infarction (STEMI).
• New ST-segment elevation at the J point in 2 contiguous leads with the cut-off point as greater than 0.1 mV in all leads other than V2 or V3.
• In leads V2-V3 the cut-off point is greater than 0.2 mV in men older than 40 years old and greater than 0.25 in men younger than 40 years old, or greater than 0.15 mV in women.
• Whereas, patients with a pre-existing left bundle branch block can be further evaluated using Sgarbossa's criteria.
• ST-segment elevation of 1 mm or more that is concordant with (in the same direction as) the QRS complex.
• ST-segment depression of 1 mm or more in lead V1, V2, or V3.
• ST-segment elevation of 5 mm or more that is discordant with (in the opposite direction) the QRS complex.^[11]
• And those underwent PTCA and admitted in department of cardiology from May 2023 to May 2024 in our study. In patient records were used to collect the required data like clinical presentation, risk factors, angiographic findings, results of PTCA and in hospital outcomes.^[11]

Plan of Statistical Analysis

The data was analysed using statistical software R- version 4.2.0, with descriptive statistics and categorical data. Continuous variables are expressed as mean ± SD, and categorical variables are expressed as frequencies and percentages. Comparisons of baseline clinical characteristics, risk factors, angiographic data, procedural data, and in-hospital outcomes were performed using analysis of variance for continuous variables and the chi square test for categorical variables and P value ≤0.05 was considered statistically significant.

Age Distribution of Participants

Gender Distribution of Participants

Distribution of Type of Population

Distribution of Participants Clinical Presentation

Distribution of Participants Personal History

Distribution of Participants Family History

Distribution of Participants Past History

Distribution of Hematocrit in Male Patients

Distribution of Hematocrit in Female Patients

Distribution of LDL in Patients

Distribution of HDL in Patients

Distribution of Participants Diagnosis

Distribution of Participants LV Function

Distribution of Participants CAG Findings

Distribution of Participants TIMI Flow

Distribution of Participants Complications Post PTCA

Distribution of Participants Hospital Stay

Distribution of Participants ICU Stay

Distribution of Participants Mortality

The study involves 54 participants, predominantly male (81.48%), majority of them within a age group of 41-45 years (50%), with 64.81% of them belonging to a rural population. Chest pain was the universal complaint, whereas other common presentation among young patients included easy fatigability (27.78%) and breathlessness (16.67%). Smoking (57.41%) was the most prevalent risk factor, with 33.33% of them having a history of diabetes mellitus. Anterior wall STEMI (75.93%) was found to be more common among young patients, with majority of them showing moderate LV dysfunction on 2D echocardiography. About 34% of the male population have raised hematocrit levels, whereas, about 50% of the total population have high low density lipoprotein and 98% of them have low high density lipoprotein. On coronary angiogram most of them had single vessel disease, with left anterior descending artery (75.93%) being most commonly involved. Nearly all patients achieved TIMI grade III flow post PTCA with no complications or mortality. The average hospital stay was for four days, with most of them spending two days in the ICU.

Few other Similar Studies are as Follows

Jagannaathan Murugan et al, conducted a cross sectional retrospective study between July 2021-2022 at tertiary care hospital in Chennai on characteristics of acute coronary syndrome among 198 young patients (age<40 years). Where 43% of the patients had risk factors, 44% had ST-elevation MI, 48% being single vessel disease thus concluding the need to identify more risk factors in young patients for aggressive preventive measures.^[3]

According to a retrospective study conducted from 2019-2021 by Ming-Ting Liang et al, on clinical risk factors and outcomes among 701 patients with acute ST-elevation myocardial infarction, 108 were aged <45 years and these younger group included more males, smokers, alcoholic, family history of ischemic heart disease, high low density lipoprotein, low high density lipoprotein and the culprit vessel in 60% of young patients being left anterior descending artery.^[4]

Limitation

The study was conducted in a single centre, so the population size is small and might not be adequate to apply to the whole of general population.

Future Directions

• More research initiatives should be taken by emergency medicine physicians to determine the burden of cardiovascular diseases among young population.
• More aggressive work up should be done among young population for burden of cardiovascular diseases.

STEMI is predominantly a disease of male population, most prevalent in rural areas. Chest pain is a universal symptom with smoking being the most common risk factor, with most of them having high low density lipoprotein, low high density lipoprotein and raised hematocrit among the male population. AWMI was found to be more common among young patients, with left anterior descending artery being the most common culprit vessel. TIMI grade 3 flow was present in nearly all the patients, with no complications or mortality post PTCA.

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