ST- Elevation Myocardial Infarction in Patients Under 40 Years old-Observational Study of More than a Decade

Background: There are little data regarding the unique features of acute myocardial infarction in young patients. We therefore aimed to examine the clinical characteristics and short and long term outcomes in patients less than 40 years admitted with ST- segment elevation myocardial infarction (STEMI).

Methods: A retrospective analysis of STEMI patients who were admitted to the Rabin Medical Center during the years 2001-2014 and underwent primary percutaneous intervention within 12 hours from the beginning of symptoms. We compared the clnical characteristics and outcomes between patients≤40 years and those> 40 years.

Results: Out of the 2578 patients included 3.68% were 40 year old or younger. Young patients were more predominantly of male gender (p=0.04), were more commonly current smokers (p=0.02), and had higher rate of family history (p<0.0001). Other traditional risk factors including hypertension, hypercholesterolemia, diabetes mellitus and past history of cardiovascular illness were less common in youngsters. Clinical presentation in young patients was milder: they were less likely to present with cardiogenic shock (p=0.04) or high Killip (III/IV) class (p=0.07). Echocardiography revealed higher involvement of the anterior wall (p=0.02), without a significant difference in global LV function. Angiography demonstrated single vessel disease in ~75% of young patients but in only about 1/3 of elders. Angiographic outcomes were comparable in both groups. We did not observe significant differences in 1 year MACE (major adverse cardiac events) of young compared with older patients.

Conclusion: STEMI in young patients is a distinct clinical entity associated with different risk factors. These patients most commonly present with anterior wall MI and have a single vessel disease. The 1-year MACE of young patients admitted with STEMI is comparable to that of older patients, although larger trials may be necessary to elucidate more subtle differences.