Resident The University Of British Columbia Burnaby, British Columbia, Canada
Background: Lipoprotein(a) (Lp(a)) is an established risk for the development of premature atherosclerotic cardiovascular disease (ASCVD) and its measurement as part of risk stratification for future cardiovascular disease is recommended by the 2021 Canadian Cardiovascular Society Dyslipidemia Guideline. However, the real-world implementation of this recommendation for primary or secondary prevention of ASCVD remains unclear. This study is the first to assess the frequency of Lp(a) measurement in a cohort of young ST-elevation myocardial infarction (STEMI) patients within a large urban Canadian setting.
METHODS AND RESULTS: We conducted a retrospective analysis of STEMI patients < 65 years old presenting to 13 regional hospitals between January 2016 and December 2022. The primary objective was to determine the proportion of patients who had baseline Lp(a) levels measured prior or within 1 year following their index STEMI hospitalization. The secondary objective was to identify predictors of Lp(a) measurement at any point in their lifetime in this population. Among 1,262 patients meeting the inclusion criteria, 1,106 (mean age 55.9±7 years, 88.1% male) were included in the final analysis. Two hundred and forty (21.7%) had an Lp(a) measurement prior or within 1 year of STEMI. Of these, 78 (32.5%) had Lp(a) levels >=100 nmol/L, while 162 (67.5%) had levels < 100 nmol/L. Based on univariable analysis, patients were less likely to have Lp(a) measured at any point in their lifetime if they were older (OR 0.71(95% CI: 0.65, 0.78) per 5-year increase, p< 0.001), had a history of hypertension (OR 0.66(0.51,0.85), p = 0.001), smoking (OR 0.64(0.48,0.85), p = 0.003), stroke/TIA (OR 0.46(0.22,0.96), p = 0.04) or a lower baseline LDL-C levels (OR 0.87 (0.77, 0.98) per mmol/L decrease, p=0.027). Older age (OR 0.68 (0.60, 0.75), p< 0.001), and smoking (0R 0.68(0.49,0.96), p=0.027) remained significantly associated with a lack of Lp(a) measurement after multivariate analysis. Approximately two-thirds had Lp(a) measured before or within 6 months of hospitalization, while one-third had their first measurement more than 12 months post-discharge.
Conclusion: In the contemporary era, only 21.7% of younger STEMI patients had LP(a) measurement within 1 year of their index event. Moreover, many patients had no Lp(a) measurement during their lifetime; this was associated with certain clinical factors such as increasing age and the presence of CAD risk factors. Strategies are needed to increase the assessment of Lp(a) amongst young patients with STEMI, especially with the development of novel targeted therapeutics.
