Violaris A G, Melkert R, Serruys P W
Catheterization Laboratory, Erasmus University, Rotterdam, The Netherlands.
Circulation. 1994 Nov;90(5):2267-79. doi: 10.1161/01.cir.90.5.2267.
Previous reports have suggested that hyperlipidemia may be associated with increased restenosis after successful coronary angioplasty. These studies have been compromised, however, by their retrospective nature, the small numbers involved, differences in the definition of restenosis, and inadequate quantitative angiographic follow-up at a prespecified time interval. The objective of the study was to examine the relation between serum cholesterol and long-term restenosis after coronary angioplasty, using quantitative angiography, at a predetermined time interval.
The study population comprised 2753 patients (3336 lesions) prospectively enrolled and successfully completing four major restenosis trials. Cineangiographic films were processed and analyzed at a central angiographic core laboratory with the use of an automated interpolated edge-detection technique. Serum total cholesterol was measured at trial entry and at 6 months. Hypercholesterolemia was defined as total cholesterol > 7.8 mmol.L-1 at trial entry. Two approaches were used to assess restenosis: first, a categorical approach using the cutoff point of > 50% diameter stenosis at follow-up and second, a continuous approach examining changes in minimal luminal dimensions, the absolute loss (change in minimum luminal diameter after PTCA to follow-up, in mm) and relative loss (absolute loss corrected for vessel size), which may give a better understanding of the underlying pathological process involved. One hundred sixty patients with 191 lesions (5.73%) had hypercholesterolemia (total cholesterol, > 7.8 mmol.L-1; mean +/- SD, 8.46 +/- 0.75 mmol.L-1) and 2593 patients with 3145 lesions (94.27%) normal cholesterol (5.67 +/- 1.06 mmol.L-1). The restenosis rate was similar in patients with and without hypercholesterolemia (31.9% versus 33.7%, respectively; relative risk, 0.975; 95% CI, 0.882 to 1.077; P = .68). Similarly, there was no difference in either the absolute or relative loss between patients with and without hypercholesterolemia (0.31 +/- 0.53 versus 0.32 +/- 0.53 mm and 0.12 +/- 0.20 versus 0.13 +/- 0.21, respectively, P = NS for both). Conversely, the total serum cholesterol in patients with restenosis (using the categorical definition) was similar to those without restenosis (5.84 +/- 1.24 versus 5.81 +/- 1.22 mmol/L, respectively, P = NS). Dividing the population into deciles according to total cholesterol and examining the categorical restenosis rate (by chi 2) as well as the absolute and relative loss by ANOVA again revealed no significant differences between deciles. Subgroup analysis of 579 patients (667 lesions) with HDL and LDL cholesterol levels available again revealed no differences in the categorical restenosis rate (by chi 2) or the absolute or relative loss between deciles according to LDL, HDL, or LDL:HDL ratio, suggesting no influence of these cholesterol subfractions on restenosis.
Our results indicate that there is no association between cholesterol and restenosis by either a categorical or continuous approach, suggesting that measures aimed at reducing total cholesterol are unlikely to significantly influence postangioplasty restenosis.
既往报道提示，高脂血症可能与冠状动脉成形术成功后再狭窄增加有关。然而，这些研究因具有回顾性、研究对象数量少、再狭窄定义不同以及在预定时间间隔内定量血管造影随访不充分而受到影响。本研究的目的是在预定时间间隔使用定量血管造影术，研究血清胆固醇与冠状动脉成形术后长期再狭窄之间的关系。
研究人群包括2753例患者（3336处病变），这些患者前瞻性入选并成功完成了四项主要的再狭窄试验。电影血管造影胶片在中央血管造影核心实验室使用自动插值边缘检测技术进行处理和分析。在试验入组时和6个月时测量血清总胆固醇。高胆固醇血症定义为试验入组时总胆固醇>7.8 mmol/L。采用两种方法评估再狭窄：第一，采用分类方法，以随访时直径狭窄>50%为界值；第二，采用连续方法，检查最小管腔尺寸的变化、绝对损失（PTCA术后至随访时最小管腔直径的变化，单位为mm）和相对损失（根据血管大小校正后的绝对损失），这可能有助于更好地理解所涉及的潜在病理过程。160例患者（191处病变，5.73%）患有高胆固醇血症（总胆固醇>7.8 mmol/L；均值±标准差，8.46±±0.75 mmol/L），2593例患者（3145处病变，94.27%）胆固醇正常（5.67±1.06 mmol/L）。有和没有高胆固醇血症患者的再狭窄率相似（分别为31.9%和33.7%；相对危险度，0.975；95%可信区间，0.882至1.077；P = 0.68）。同样，有和没有高胆固醇血症患者的绝对或相对损失均无差异（分别为0.31±0.53和0.32±0.53 mm以及0.12±0.20和0.13±0.21，两者P均无统计学意义）。相反，有再狭窄患者（采用分类定义）的血清总胆固醇与无再狭窄患者相似（分别为5.84±1.24和5.81±1.22 mmol/L，P无统计学意义）。根据总胆固醇将人群分为十分位数，并通过卡方检验检查分类再狭窄率以及通过方差分析检查绝对和相对损失，结果再次显示十分位数之间无显著差异。对579例患者（667处病变）进行的亚组分析，这些患者有高密度脂蛋白（HDL）和低密度脂蛋白（LDL）胆固醇水平数据，结果再次显示，根据LDL、HDL或LDL:HDL比值分为的十分位数之间，分类再狭窄率（通过卡方检验）或绝对或相对损失均无差异，提示这些胆固醇亚组分对再狭窄无影响。
我们的结果表明，无论是采用分类方法还是连续方法，胆固醇与再狭窄之间均无关联，这表明旨在降低总胆固醇的措施不太可能显著影响血管成形术后再狭窄。
