待機的冠動脈ステント留置術後の再狭窄と血中Lipoprotein（a）濃度に関する検討

Lipoprotein (a) and Restenosis after Elective Coronary Stenting

要旨　待機的冠動脈ステント留置術後の再狭窄と血中Lp（a）濃度の関係を検討した．待機的冠動脈ステント留置に成功し，6カ月後に冠動脈造影を施行した連続86症例（男性65例，女性21例，平均年齢65.0±9.3歳），96病変（LAD 50，RCA 29，LCX 17）を対象とした．慢性期に血中Lp（a）濃度を測定し30mg/dl以上の高Lp（a）群（II群：n＝31）と30mg/dl未満の低Lp（a）群（L群：n＝65）とに分け再狭窄について検討した．その他の冠危険因子として，高血圧，糖尿病，喫煙，家族歴，高脂血症の有無についても評価した．年齢，性別，その他の冠危険因子に両群で有意差は認めなかった．冠動脈造影にて再狭窄を認めたのは96病変中28病変で，再狭窄率は，H群では19.4％（6/31），L群では33断8％（22./65）と両群で有意差は認めなかつた．待機的冠動脈ステント留置術は再狭窄に関して高Lp（a）血症の影響をうけず，高Lp（a）血症を有する患者にも有効であることが示唆された．

　Lipoprotein (a) 〔Lp (a)〕 appears to be a risk factorfor coronary artery disease. It may promote restenosisafter balloon angioplasty.

　The aim of this study was to evaluate the relationbetween serum Lp (a) level and restenosis after electivecoronary stenting.

The study included 86 patients (96 lesions) with successful coronary stent placement. Follow-up angiography was performed at 6 months after stent placement.At follow-up, serum biochemical data and coronary riskfactor were analyzed. According to the serum Lp (a)level, lesions were divided in two groups: high Lp (a)group (serum Lp (a)≧3mg/dl) and low Lp (a) group (serum Lp (a)＜30mg/dl).

　Lp (a) level was 32.5±40.3mg/dl (median, 20 mg/dl;range, 2 to 254mg/dl). Total restenosis rate was 29.1%.Angiographic restenosis occurred in 6 of the 31 lesions(19.4%) in the high Lp (a) group and in 22 of the 65lesions (33.8%) in the low Lp (a) group. There was nodifference between the two groups statistically.

　Serum Lp (a) level did not influence restenosis afterelective stent placement.