Homocysteine and long-term recurrent infarction following an acute coronary syndrome.

BACKGROUND: There are no well-established predictors of recurrent ischemic coronary events after an acute coronary syndrome (ACS). Higher levels of homocysteine have been reported to be associated with an increased atherosclerotic burden. The primary endpoint was to assess the relationship between homocysteine at discharge and very long-term recurrent myocardial infarction (MI). METHODS: 1306 consecutive patients with ACS were evaluated (862 with non-ST-segment elevation ACS [NSTEACS] and 444 with ST-segment elevation myocardial infarction [STEMI]) discharged from October 2000 to June 2003 in a single teaching-center. The relationship between homocysteine at discharge and recurrent MI was evaluated through bivariate negative binomial regression accounting for mortality as a competitive event. RESULTS: The mean age was 66.8 ± 12.4 years, 69.1% were men, and 32.2% showed prior diabetes mellitus. Most of the patients were admitted for an NSTEACS (66.0%). The median (interquartile range) GRACE risk score, Charlson comorbidity index, and homocysteine were 144 (122-175) points, 1 (1-2) points, and 11.9 (9.3-15.6) µmol/L, respectively. In-hospital revascularization was performed in 26.3% of patients. At a median follow-up of 9.7 (4.5-15.1) years, 709 (54.3%) deaths were registered and 779 recurrent MI in 478 (36.6%) patients. The rates of recurrent MI were higher in patients in the upper homocysteine quartiles (p < 0.001). After a multivariate adjustment, homocysteine along its continuum remained almost linearly associated with a higher risk of recurrent MI (p = 0.001) and all-cause mortality (p < 0.001). CONCLUSIONS: In patients with ACS, higher homocysteine levels identified those at a higher risk of recurrent MI at very long-term follow-up.

Lipoprotein(a) and long-term recurrent infarction after an episode of ST-segment elevation acute myocardial infarction.

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.