Comparison of Prevalence, Presentation, and Prognosis of Acute Coronary Syndromes in ≤35 years, 36 - 54 years, and ≥ 55 years Patients.

Whether very young patients (≤35-year-old) differ in the prevalence, presentation and prognosis of ACS is not well known. Of 43,446 patients who were referred to a tertiary care cardiac catheterization laboratory between January 1, 2006 and June 30, 2017, 26,545 patients were ACS (defined as ST Elevation MI, Non-ST Elevation MI or unstable angina pectoris). Detailed chart review was performed and characteristics at baseline were compared for ages ≤35 years, ages 36 to 54 years and ages ≥55 years. A total of 291 (1.1%) were ≤35-year-old, 7,649 (28.8) were 36 to 54-year-old and 18,605 (70.1%) were ≥55-year-old. ACS patients aged ≤35-year-old, were more likely to be men, Caucasian white, smoker, obese, and have family history of coronary artery disease and less likely to have comorbidities such as hypertension, diabetes mellitus, and hyperlipidemia compared with older patients. They were also more likely to present with elevated troponin levels than other groups. They also tended to present with late ST elevation myocardial infarction and were more likely to receive bare metal stents than older patients. The prevalence of 2- and 3-vessel disease was lower compared with older patients. They also had higher prevalence of cardiogenic shock. Compared with 36 to 54-year-old patients, ≤35-year-old were at significant higher risk of 30-day mortality in a multivariable adjusted regression model (Odds ratio 5.65, 95% confidence interval 2.49 to 12.82, p <0.001). Very young patients comprised ∼1% of all ACS cases but had much more prevalence of modifiable risk factors and significantly worse mortality. Modifying these risk factors may mitigate the risk in these patients and should be studied in the future.