Impact of serum lipoprotein (a) level on coronary plaque progression and cardiovascular events in statin-treated patients with acute coronary syndrome: a yokohama-acs substudy

Background: Lipoprotein (a) [Lp(a)] has been reported to be a residual risk factor in patients who have achieved target lipid levels. The aim of the present study was to investigate the associations of Lp(a) with plaque progression and major cardiovascular events in patients with acute coronary syndromes (ACS).

Methods: The Yokohama-ACS study included 102 patients with ACS who underwent intravascular ultrasound (IVUS) at baseline and at 10-month follow-up after percutaneous coronary intervention (PCI). The patients were randomly assigned to receive either moderate- or low-intensity statin therapy. IVUS was performed to measure the plaque volume at non-culprit lesions. We enrolled 76 patients for whom Lp(a) levels at 10-month follow-up were available.

Results: The patients were divided into 2 groups according whether their Lp(a) levels were ≤20 mg/dl [low Lp(a) group; n = 49] or >20 mg/dl [high Lp(a) group; n = 27]. Baseline characteristics and low-density lipoprotein cholesterol levels at 10-month follow-up were similar in the low Lp(a) group and high Lp(a) group (87 ± 29 mg/dl vs. 93 ± 27 mg/dl, p = 0.42). The low Lp(a) group had significant plaque regression, whereas the high Lp(a) group showed slight plaque progression (-6.8% vs. 2.5%, p = 0.02). Ninety-five percent of the prognostic data were obtained 5 years after PCI. The cumulative event-free survival rate was significantly lower in the high Lp(a) group (p = 0.02; log-rank test).

Conclusions: Lp(a) levels may be an alternative predictor of further plaque regression and the likelihood of major adverse cardiovascular events in statin-treated ACS patients.