European Journal of Cardiovascular Medicine

Cardiovascular diseases (CVD) represent a significant public health concern globally, with a particularly alarming impact in India. According to the World Health Organization (WHO), India accounts for one-fifth of global CVD-related deaths, a disproportionate burden especially affecting the younger population. The Global Burden of Disease survey reports that India's age-standardized CVD fatality rate is 272 per 100,000 people, markedly higher than the global average of 235 per 100,000 ¹. In 2017, CVD was responsible for 26.6% of all deaths and 13.6% of total disability-adjusted life years (DALYs) in India, a substantial increase from 15.2% of deaths and 6.9% of DALYs in 1990 ².

Coronary artery disease (CAD) prevalence notably increases after the age of 35 in both men and women. The lifetime risk of developing CAD after 40 years of age is estimated at 49% for men and 32% for women³. Despite this, patients under the age of 45 years with CAD represent a unique subgroup requiring focused attention. Most research traditionally uses 45 years as the threshold to categorize young individuals with CAD and myocardial infarction (MI), leaving the subset of very young (≤30 Yrs) less examined.

This paper aims to bridge this gap by presenting a comparative analysis of clinicodemographic, risk factors, and angiographic profiles of very young and older young adult (31-45 years) patients with acute coronary syndrome (ACS) in the Indian population. Understanding these differences is crucial for tailoring preventive and therapeutic strategies. The findings will highlight the distinctive characteristics and needs of the very young CAD patients, underlining the necessity for targeted interventions in this emerging subset. This study is especially essential for India, given its significant and growing young population vulnerable to CVD.

Study Design: This was an investigator initiated, single-center, retrospective, observational study, which was conducted to evaluate the clinicodemographic, risk factors and angiographic profile of ACS in young adults, undertaken at a tertiary Cardiology Institute in Central India.

The study was approved by local ethical committee. This study was conducted according to the ICH Harmonized Guidelines for Good Clinical Practice, applicable local regulations. CAG and 2D-ECHO were performed by trained cardiologists following hospital protocols. Angiographic measurements were made using by visual estimation by two cardiologists. A Diameter stenosis of 50% in the coronary segment was considered significant.

Data Collection: We reviewed medical records of 550 young adults (18 to ≤ 45 years) diagnosed with Acute Coronary Syndrome (ACS) between January 2018 and July 2023. Information on demographics, comorbidities, addiction history, laboratory parameters, 2D-echocardiography, and Coronary angiography findings was recorded in Microsoft Excel.

Statistical Analysis: We included all eligible patients within the hospital database during the specified timeframe. Descriptive statistics for data were computed. Representation of continuous variables was expressed by mean and standard deviation (SD); conversely the categorical variables were shown with frequency and percentage. For intergroup analysis on metric parameters, chi-square test was used to find out the significance to the study parameters on categorical scale between the groups. Significance was assessed at 5% level of significance where p-values reported in this study were based on two-sided test with a p < 0.05 is considered as significant. The statistical analysis was performed using SPSS trial version 20.

The study cohort comprised a total of 550 cases. Of these participants, 90.4% were male (n=497) and 9.6% were female (n=53). The age of the patients ranged from 22 to 45 years, with a mean age of 40.24 years. For analytical purposes, the patients were divided into two groups: those under 30 years and those 30 years or older. Demographic characteristics and medical histories are detailed in Fig. 1 and Fig. 2. Obesity was identified as the most prevalent risk factor, present in 222 cases (40.4%). Other significant risk factors included hypertension in 213 cases (38.7%), diabetes mellitus in 168 cases (30.5%), and hyperlipidaemia in 46 cases (8.4%). Additionally, 72 patients (13.1%) reported smoking or tobacco use, and 59 patients (10.7%) reported alcohol consumption.

Figure 1: Demographic characteristics: Age distribution (years)

Figure 2: Demographic characteristics: Risk factors (%)

A comparative analysis was performed to assess the correlation between coronary risk factors and age groups, coronary angiographic profiles and age groups, coronary risk factors and ejection fraction (EF), and age groups.

There was a significantly higher prevalence of traditional risk factors among patients over 30 years of age compared to those under 30. Specifically, the prevalence of hypertension and diabetes mellitus (DM) was statistically significant, with p-values of 0.001 and 0.003, respectively. The findings are summarized in Table 1 and Fig 3

TABLE 1- Association between coronary risk factors and young ACS.

Table 2 and Fig 4 provide comparative analysis of coronary angiographic profiles by age group. Among the cases with single-vessel disease, 22 (8.9%) were under 30 years, while 226 (91.1%) were over 30 years. In cases of double-vessel disease, 1 (0.7%) was under 30 years, and 140 (99.3%) were over 30 years. Notably, no patients under 30 years had triple-vessel disease, whereas all 92 (100%) cases of triple-vessel disease occurred in patients over 30 years.

TABLE 2- Association between angiographic profile of young ACS.

Figure 4: Comparative analysis of coronary angiographic profile between Age Groups

For the comparative analysis of ejection fraction (EF) and coronary risk factors, EF was divided into two groups: <40% and >40%. The results showed a significant association between hypertension and reduced EF (p = 0.037). Among the hypertensive patients, 32 (17.1%) had reduced EF, while 155 (82.9%) had EF >40%. No significant differences were found between EF groups and overweight (p = 0.307), diabetic (p = 0.101), and hyperlipidaemic patients (p = 0.128). Similarly, no statistically significant differences were observed between EF groups and smokers or tobacco users (p = 0.497), or alcoholics (p = 0.374).

This study also evaluated the association between coronary risk factors and EF across age groups, detailed in Figure 5. Out of total cases of hypertension, none of the patients under 30 years had abnormal EF, compared to 32 (17.2%) in those above 30 years which indicates non-significant association between coronary risk factors and EF across age.

Additionally, there was no significant association between age and EF (p = 0.173). In the group under 30 years old, 8 (33.3%) had reduced EF, while 16 (66.7%) had EF >40%. In the group aged 30 years and older, 100 (21.5%) had reduced EF, and 365 (78.5%) had EF >40%. These findings are summarized in  Fig 6 below .

Figure 5: Comparative analysis of coronary risk factors and ejection fraction

Figure 6: Comparative analysis of ejection fraction and Age

Table 3 and figure 7, illustrate that in the overall cohort (N=550), the Left Anterior Descending artery (LAD) was the most commonly involved artery, affecting 47.6% of patients, followed by the Right Coronary Artery (RCA) in 21.5%, and the Left Circumflex (LCX) in 13.3%.

Table 3 : Profile of Artery Involved

Figure 7: Profile of Artery Involved

A comparison based on age groups Depicted in Table 4 and Figure 8 showed significant differences (p=0.033), with a higher proportion of LAD involvement in patients under 30 years (68.0%) compared to those over 30 years (46.9%). LCX involvement was absent in patients under 30 but present in 13.9% of those over 30. Similarly, RCA and OM involvement was significantly higher in the older age group compared to younger patients. The involvement of LPDA showed no significant age-based differences.

Table 4 : Comparison of Artery Involved as per Age groups

By Chi-square test, p<0.05, *Significant

Figure 8: Comparison of Artery Involved as per Age groups

While CAD is relatively rare among young adults in Western populations, it is more prevalent and  in Southeast Asian populations . Cardiovascular diseases (CVD) are the top cause of death and disability in India, characterized by a higher risk, earlier onset, increased fatality, and more premature deaths. A 2014 study by the World Economic Forum and Harvard estimated that India could lose nearly $2.17 trillion in GDP due to CVD by 2030 ⁴. In India, 25% of acute MIs occur in people under 40, and 50% in those under 50. One center reported a 47-fold increase in first MIs in those under 40 over the last 20 years ^5,6.

Moreover, there has been a surge in ACS cases among an even younger population, specifically those under 30 years of age, who are increasingly presenting with this condition.  Given this alarming increase in ACS cases among patients in Asian subcontinent, under 30 years—a group with limited existing literature—there is a pressing need to focus on this population. Our single-center study in India specifically analysed ACS in patients under 45 years, with a detailed comparison between the very young cohort (<30 years) and those aged 30-45 years.

Our study analyzed a cohort of 550 patients with acute coronary syndrome (ACS) under the age of 45. Among these, the majority were male, with 90.4% (n=497) being men and 9.6% (n=53) women, consistent with other Indian studies reporting a similar male predominance of approximately 95%^7,8. The patients' ages ranged from 22 to 45 years, with a mean age of 40.24 years.

To specifically assess the impact of age, we divided the cohort into two groups: those under 30 years (n=25, 4.5%) and those aged 31 to 45 years (n=525, 95.5%). A comparison between these groups revealed that the prevalence of diabetes and hypertension was significantly higher in the 31-45 age group compared to the very young cohort. These findings align with previous studies showing a lower prevalence of hypertension and diabetes in very young patients, estimated at around 12%. However, other risk factors, such as smoking, alcohol use, obesity, and hyperlipidemia, did not differ significantly between the two age groups. In our study, obesity and hypertension emerged as the most prevalent risk factors, affecting 40.4% and 38.7% of the participants, respectively. It is noteworthy that 10% (n=55) of the patients had no identifiable risk factors.

Nearly all patients under 30 years presented with single-vessel disease, a significantly higher proportion compared to the older age group (p < 0.001) aligning with a study by Deshmukh et all ⁷. Notably, none of the patients under 30 years had triple-vessel disease, whereas all 92 cases of triple-vessel disease were observed in patients over 30 years, a difference that is statistically significant. Ejection fraction, however, did not show any significant difference between the two age groups.

Limitation - This study has several limitations. Its retrospective design restricts long-term follow-up, preventing the documentation of major cardiovascular outcomes.  Lipid profile data were not present in all patients, which limits risk stratification. The lack of intravascular imaging also hampers the ability to distinguish between atherosclerotic and non-atherosclerotic causes of CAD, particularly in very young patients. Finally, the single-center nature and small sample size limit the generalizability of our findings to the broader population.

Our study provides valuable insights into the clinico-demographic characteristics, risk factors, and angiographic profiles of ACS in young adults. Young ACS patients exhibit a strong male predominance. Although Obesity and hypertension emerged as the most common risk factor, affecting around 40% of participants, conventional risk factors, such as diabetes and hypertension, are significantly less prevalent in patients younger than 30 years compare to older young patients. This very young cohort predominantly presents with single-vessel disease with a statistically significant involvement of LAD and, with a significantly lower incidence of multivessel involvement compared to older young patients. The older young adults (over 30 years) are more likely to have multiple vessel disease compared to those under 30 years. These findings underscore the importance of early detection and management of risk factors in young adults to prevent the progression of ACS and reduce long-term morbidity and mortality.

1. Vale N, Nordmann AJ, Schwartz GG, de Lemos J, Colivicchi F, den Hartog F, Ostadal P, Macin SM, Liem AH, Mills EJ, Bhatnagar N, Bucher HC, Briel M. Statins for acute coronary syndrome. Cochrane Database of Systematic Reviews 2014, Issue 9. Art. No.: CD006870. DOI: 10.1002/14651858.CD006870.pub3. Accessed 10 July 2024.
2. Egred M, Viswanathan G, Davis GK, et al. Myocardial infarction in young adults. Postgrad Med J. 2005;81:741‐745
3. Singh A, Museedi AS, Grossman SA. Acute Coronary Syndrome. [Updated 2023 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459157/
4. https://doi.org/10. 1016/j.lansea.2023. 100156
5. Sapkal Harish Barsu, Chandrakant Raibhoge, Deshpande Neelima S, Dawle Kiran. A study of cardiovascular risk factors profile in young patients with acute myocardial infarction. MedPulse International Journal of Medicine. May 2020; 14(2): 55-58. https://www.medpulse.in/Medicine/
6. Mammi MV, Pavithran K, Abdu Rahiman P, Pisharody R, Sugathan K. Acute myocardial infarction in North Kerala – A 20 year hospital based study. Indian Heart J 1991;43:93‑6.
7. Deshmukh PP, Singh MM, Deshpande MA, Rajput AS. Clinical and angiographic profile of very young adults presenting with first acute myocardial infarction: Data from a tertiary care center in Central India. Indian Heart J. 2019 Sep-Oct;71(5):418-421. doi: 10.1016/j.ihj.2019.12.004. Epub 2020 Jan 3. PMID: 32035526; PMCID: PMC7013186.
8. Revaiah PC, Vemuri KS, Vijayvergiya R, Bahl A, Gupta A, Bootla D, Kasinadhuni G, Nevali KP, Palanivel Rajan M, Uppal L, Gawalkar A, Rohit M. Epidemiological and clinical profile, management and outcomes of young patients (≤40 years) with acute coronary syndrome: A single tertiary care center study. Indian Heart J. 2021 May-Jun;73(3):295-300. doi: 10.1016/j.ihj.2021.01.015. Epub 2021 Jan 17. PMID: 34154745; PMCID: PMC8322929.