This study was designed to test the hypothesis that high plasma lipoprotein (a) (Lp[a]) levels are associated with an increase incidence of restenosis after angioplasty. Elective transluminal coronary angioplasty was performed in 66 patients (58 men and 8 women) aged 57 +/- 9 years (mean +/- SD). Two days before and 5 days after angioplasty, all patients underwent low-density lipoprotein (LDL) apheresis with a dextran sulfate cellulose column as an Lp(a) absorbent; 39 patients also received 10 mg of pravastatin and 1,500 mg of niacin daily. Restenosis was defined as a recurrent luminal stenosis of > or = 50% in a previously dilated segment. Median Lp(a) levels were reduced from 23.3 mg/dl before apheresis to 10.9 mg/dl after apheresis (p < 0.0001). Angiography performed 2 to 9 months after angioplasty revealed restenosis in at least 1 site in 38% of the 137 control patients and in 32% of the 66 patients who underwent apheresis. Restenosis also occurred in 37% of the patients who underwent apheresis alone and in 28% of the patients who also received pravastatin and niacin in combination with LDL apheresis. The restenosis rate was 21% in the 42 patients whose Lp(a) levels were significantly reduced > or = 50%, and in 50% of the 24 patients whose Lp(a) levels were significantly reduced < 50% (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)