By Michael H. Crawford, MD
Professor of Medicine, Associate Chief for Education, Division of Cardiology, University of California, San Francisco
Dr. Crawford reports no financial relationships relevant to this field of study.
SYNOPSIS: A retrospective contemporary review of STEMI patients younger than 35 years of age shows that these patients are predominantly overweight men who smoke (some abuse drugs and present with dyslipidemia).
SOURCE: Ruiz Pizarro V, Palacios-Rubio J, Cruz-Utrilla A, et al. ST-elevation myocardial infarction in patients ≤ 35 years of age. Am J Cardiol 2019;123:889-893.
Although infrequent, acute ST-elevation myocardial infarction (STEMI) in patients younger than 35 years of age can devastate quality of life. To better understand clinical profile and prognosis of such patients, investigators from Madrid evaluated STEMI patients ≤ 35 years of age from three urban hospitals between 2004 and 2016. All three hospitals were percutaneous coronary intervention (PCI) centers. The authors performed an extensive initial determination of clinical factors and followed patients for major adverse cardiac events (MACE) over an average of six years.
Out of 3,883 STEMI patients at the three hospitals, 61 were ≤ 35 years of age, with a mean age in this cohort of 32 years. Most were men (88%), smokers (80%), and overweight (67%). Only 3% did not exhibit conventional risk factors. Compared to a similar-aged reference group from the Spanish population, young STEMI patients more often were diabetic, exhibited dyslipidemia, were overweight, and smoked.
Drug abuse was discovered in 26% of these patients. Almost all patients underwent primary PCI (87%); the rest underwent thrombolysis before PCI. Although complications during hospitalization were infrequent, the hospital mortality rate was 5%. The long-term survival rate was 97%, and the MACE rate was 17%. The authors concluded that despite the rarity of STEMI in patients ≤ 35 years of age, such patients present with modifiable predisposing conditions and an excellent long-term prognosis.
This study is important because it is a contemporary cohort of young patients with STEMI treated at large urban PCI centers. Perhaps not surprisingly, such young patients are rare, comprising 1-2% of all STEMIs. However, these young STEMI patients feature a unique clinical profile. They are mostly male smokers who are overweight. The only other clinical factors that rise above a prevalence of one-quarter of the cohort are dyslipidemia (32%) and drug abuse (26%). Common risk factors found in older patients were uncommon in this cohort: diabetes (15%) and hypertension (16%). Unusual causes in older patients, which one would assume to be more common in this young cohort, were surprisingly low: familial hypercholesterolemia (5%) and HIV (3%).
Despite experiencing a STEMI, which was caused by an occlusion of the left anterior descending coronary artery in two-thirds of this young cohort, complications were infrequent. Most were Killip class I (85%); a majority exhibited left ventricular ejection fraction > 50%. The hospital mortality rate was 5%, while the total mortality rate over the six-year follow-up was 8% (includes hospital mortality). The MACE rate was 17%.
There are some limitations to this study. The authors did not include patients with spontaneous coronary artery dissection or MI with normal coronary arteries. The authors also excluded patients with non-STEMI and type II MI. In addition, this was a homogeneous population of Mediterranean people; thus, the results may not be applicable to other populations. Finally, the authors reported no data on the subsequent management of these patients.
Although as a group these young patients performed well, some died; others were left with impaired left ventricular function. Thus, these data inform a public health opportunity since the major factors predisposing these patients to STEMI are largely modifiable. Young men should not smoke, should maintain a normal weight, should keep their lipid values in the desirable range, and should not abuse drugs. If these goals are accomplished, the number of STEMI episodes in young men could approach zero.