Background: In established ischemic heart disease, the relationship between lipoprotein(a) and new cardiovascular events showed contradictory results. Our aim was to assess the relationship between lipoprotein(a) and very long-term recurrent myocardial infarction (MI) after an index episode of ST-segment elevation acute myocardial infarction (STEMI).
Methods: We included 435 consecutive STEMI patients discharged from October 2000 to June 2003 in a single teaching center. The relationship between lipoprotein(a) at discharge and recurrent MI was evaluated through negative binomial regression and Cox regression analysis.
Results: The mean age was 65 years (55-74 years), 25.5% were women, 34.7% were diabetic, and 66% had a MI of anterior location. Fibrinolysis, rescue, or primary angioplasty was performed in 215 (49.4%), 19 (4.4%), and 18 (4.1%) patients, respectively. The median lipoprotein(a) was 30.4 mg/dL (12-59.4 mg/dL). After a median follow-up of 9.6 years (4.1-15 years), 180 (41.4%) deaths and 187 MI in 133 (30.6%) patients were recorded. After a multivariate adjustment, the risk gradient of lipoprotein(a) showed a neutral effect along most of the continuum and only extreme higher values identified those at higher risk of recurrent MI (P = 0.020). Those with lipoprotein(a) values >95th percentile (≥135 mg/dL) showed a higher risk of recurrent MI (incidence rate ratio, 2.34; 95% confidence interval, 1.37-4.02; P = 0.002). Lipoprotein(a) was not related to the risk of mortality (P = 0.245).
Conclusions: After an episode of STEMI, only extreme high values of lipoprotein(a) were associated with an increased risk of long-term recurrent MI.