Usefulness of Serum Lipoprotein (a) as a Predictor of Restenosis After Percutaneous Transluminal Coronary Angioplasty James A. Hearn, MD, Bryan C. Donohue, MD, Hisham Ba’albaki, MD, John S. Douglas, MD, Spencer B. King III, MD, Nicholas J. Lembo, MD, Gary S. Roubin, MD, PhD, and Demetrios S. Sgoutas, PhD

Serum lipoprotein (a) &Ma]) has been associated with coronary artery atherosclerosis. Its association with restenosis after percutaneous transluminal coronary angioplasty (PTCA) has not been previously studied. Serum levels of Lp(a), in addition to other lipoproteins, and their components using standard assays, were determined in subjects undergoing cardiac catheterization within 10 months after PTCA. Clinical (e.g., sex, diabetes, angina class) and angiographic (e.g., PTCA percent diameter reduction) factors were not different between the group without (diameter reduction lS mg/dl was associated with an odds ratio of 5.9 (95% confidence interval 4.6 to 7.2) (restenosis rates of 58% in the group with 0 to 19 mg/dl and 89% in the group with 19 to 120 mg/dl; p = 0.006). Hence, serum Lp(a) appears to be a potent predictor of restenosis in subjects returning for coronary arteriography after PTCA. (Am J Cardiol lSS2;69:736-739)

P

ercutaneous transluminal coronary angioplasty (PTCA) has been shown to be effective at relieving myocardial ischemia in patients with coronary artery disease.*Its major limitation is restenosis, which occurs in approximately 30% of lesionswith subsequentrequirement for further revascularization in the form of repeat PTCA or coronary artery bypassgrafting.2 Whereas serum cholesterol and other lipoproteins may be important in the developmentof coronary artery disease,their role in coronary restenosisremains unclear.3-6Previous analysis of apolipoprotein (apo) A-I and apo B, revealed no significant association of any lipid with coronary restenosis.6Serum lipoprotein (a) (Lp[a]) has not been previously reported after PTCA. Lp(a) is a low-density lipoprotein (LDL)-like lipoprotein that is characterized by its specific ape(a). Ape(a) is bound by disulfide linkage to apo Blm in the shell of the LDL particle.‘,* Previousreports have estab lished that elevated Lp(a) is a predictor of myocardial infarction,9J0 angiographic coronary artery disease,“J2 and vein graft stenosis after bypass procedures.13 Ape(a) has beendemonstratedto be histochemically localized to diseasedvein grafts,14and to human coronary arteries.15Interest has been focused on Lp(a) through the recent finding of a close homology to plasminogen and the speculation that Lp(a) inhibits fibrinolysis by competing with tissue-type plasminogenactivator16and plasminogen,” for fibrin binding. Another possibility is inhibition of local tissue plasminogenactivator secretion from endothelial ~~11s.~~ We undertook this observational study to determine if serum Lp(a) had any predictive value for restenosis. METHODS

Patients: Sixty-nine patients having had PTCA within the preceding 1 week to 10 months returned (85% with recurrent angina) for diagnostic cardiac catheterization and coronary arteriography to determine the presence of coronary restenosis,defined as 150% diameter obstruction in a previously dilated coronary arterial segment.This group does not include patients who returned to Emory University Hospital for From the Andreas Gruentzig CardiovascularCenter, Division of Cardirestenosis and who underwent cardiac catheterization at ology, Department of Medicine, and Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, their referring hospital or patients who returned in reGeorgia; and the Division of Cardiology, University of Alabama, Bir- sponseto acute events such as myocardial infarction. mingham, Alabama. Manuscript receivedJuly 2, 1991;revisedmanuFasting lipid samples were obtained before any script receivedNovember 25,1991, and acceptedNovember 30. heparinization or intravascular contrast administration Address for reprints: Demetrios S. Sgoutas,PhD, Pathology and Laboratory Medicine, Emory University Schoolof Medicine, Atlanta, since the effects of these agents on serum Lp(a) are unknown. Exclusion criteria were cigarette smokers, Georgia 30322.

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THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 69

MARCH 15, 1992

TABLE

I Demographic

Restenosis No. of patients Age (yr) Men/women Systemic hypertension (%I Diabetes mellitus (%) Positive family history of CAD (%) Vein grafts (%I Total occlusions (%I Angina class No. of diseased vessels Prior PTCA at site Pre-PTCA % diameter Post-PTCA % diameter Follow-up % diameter

and Clinical

TABLE

Characteristics

Group A

Group B

p Value

0 20 59-t 11 1515 12 (60) 4 (20)

+ 49 58+ 11 6113 17 (36) 9 (18)

NS NS NS NS

10 (50) 2 (10) 0 (0) 2.9 r 1.5 1.45 2 0.69 1.55 + 1.05 75 r+ 9 21 + 10 25 2 14

27 (55) 4 (8) 8 (16) 2.8 + 1.4 1.35 + 0.63 1.22 2 0.51 76k 15 21 + 11 74 -t 14

Values are expressed as mean k SD. CAD = coronary artery disease; NS = not statlstlcally slgnkant hmits; PTCA = percutaneous transluminal coronary angloplasty; absent.

NS NS NS NS NS NS NS NS

Usefulness of serum lipoprotein (a) as a predictor of restenosis after percutaneous transluminal coronary angioplasty.

Serum lipoprotein (a) (Lp[a]) has been associated with coronary artery atherosclerosis. Its association with restenosis after percutaneous translumina...
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