Fate of side branches after coronary arterial sirolimus-eluting stent implantation

The sirolimus-eluting stent (SES) is emerging as a potential solution for the prevention of restenosis. Although the outcome of side branches after stenting with an uncoated metal stent (UMS) has been reported, the fate of side branches after SES implantation is unknown. Furthermore, the absence of spontaneous recanalization of occluded side branches following intracoronary brachytherapy has been previously described and has been related to a delayed healing process. We assessed the procedural and 6-month follow-up angiograms of 238 patients enrolled in the RAVEL study, a double-blind controlled trial of the SES versus the UMS. Any side branch seen on the preprocedure angiogram and subsequently covered by the stent was evaluated. The side branch Thrombolysis In Myocardial Infarction (TIMI) flow grade was assessed at baseline and at follow-up by 2 observers. One hundred twenty-eight patients with > or =1 side branches were identified (63 patients in the SES group with 118 side branches, 65 patients in the UMS group with 124 side branches). Side branch occlusion occurred after stenting in 12 branches (10%) in the SES group and in 9 branches (7%) in the UMS group (p = NS). Of these occluded branches, spontaneous recanalization was observed in 11 branches (92%) in the SES group and in 6 branches (67%) in the UMS group at follow-up angiography (p = NS). Thus, the fate of side branches after SES implantation is favorable and at least as good as after UMS implantation.     

Natural history of small and medium-sized side branches after coronary stent implantation

Objective Our purpose was to identify angiographic and procedural predictors for acute and late side branch occlusion after coronary stent implantation. Methods We evaluated 185 patients with 185 lesions with 255 side branches with a mean reference diameter of 1.45 ± 0.38 mm; the lesions were covered by 240 stents. Angiographic follow-up was completed in 99 patients with 133 side branches 206 ± 120 days after stent implantation and clinical follow-up was available in 136 patients. Side branch occlusion (SBO) was defined as a Thrombolysis In Myocardial Infarction (TIMI) flow ≤1. Results Acute SBO affected 54 side branches in 49 patients and was not associated with death or Q-wave infarction. By logistic regression, independent predictors for acute SBO were (1) the reference side branch diameter (RLD) at baseline (OR [odds ratio] 0.217, 95% CI 0.07-0.67, P = .008); (2) an ostial side branch stenosis before stenting (OR 2.96, 95% CI 1.26-6.95, P = .013); (3) the involvement of the side branch origin within the lesion of the parent vessel (OR 2.77, 95% CI 1.17-6.57, P = .021); and (4) the balloon-to-artery ratio (OR 4.66, 95% CI 1.18-18.42, P = .028). Among the initially occluded side branches, 81.8% were spontaneously reperfused at follow-up. Late SBO involved 12% of the side branches without impaired antegrade flow after stenting and was predicted by the initial RLD of the side branch (OR 0.07, 95% CI 0.01-0.8, P = .032). Chronic SBO occurred in 13.5% of cases and was also predicted by the baseline RLD (OR 0.13, 95% CI 0.02-0.8, P = .028). Conclusions Acute SBO after stenting occurred in 21.2% of cases and had a benign course. Most acutely occluded side branches underwent late spontaneous reperfusion. A baseline side branch diameter >1.4 mm predicted a preserved antegrade flow immediately after stent implantation, as well as during follow-up. (Am Heart J 2002;143:627-35.)     

Contemporary stent treatment of coronary bifurcations

Treatment of coronary bifurcation lesions represents a challenging area in interventional cardiology. The introduction of drug-eluting stents (DES) reduced restenosis in the main branch (MB). However, restenosis at the ostium of the side branch (SB) remains a problem. Although stenting the MB with provisional SB stenting seems to be the prevailing approach, in the era of DES various two-stent techniques emerged (crush) or were re-introduced (V or simultaneous kissing stents, crush, T, culottes, Y, skirt) to allow stenting in the SB when needed. This review describes in detail various techniques used for implantation of two stents by intention to treat.     

Chest pain after coronary artery stent implantation

A sizeable proportion of patients who undergo successful coronary artery stent implantation experiences chest pain immediately after the procedure and/or in the following months in the absence of in-stent restenosis. We investigated this phenomenon in 57 consecutive patients with stable angina who underwent successful stent implantation. Chest pain characteristics were assessed before stent implantation and during 6-month follow-up. All patients underwent coronary angiography within 6 months of the procedure 48 hours after exercise thallium-201 perfusion scintigraphy. Patients who did not exhibit in-stent restenosis underwent an ergonovine test at the end of routine coronary angiography. During follow-up, 15 patients complained of chest pain. Six of these patients exhibited scintigraphic evidence of myocardial ischemia and in-stent restenosis at angiography. In the remaining 9 patients, chest pain occurred in the absence of in-stent restenosis at angiography. In 8 of these patients intracoronary ergonovine administration reproduced their habitual pain, whereas it did not cause any pain in the 42 patients who were completely asymptomatic at follow-up and without in-stent restenosis. Ergonovine caused more intense vasoconstriction and nitroglycerin caused more intense vasodilation of the reference coronary diameter in patients with than in patients without ergonovine-induced pain (-17 +/- 3 vs -9 +/- 3%, p <0.001; 9 +/- 6 vs 5 +/- 4%, p <0.02, respectively). In conclusion, chest pain with features similar to habitual angina occurs in the absence of in-stent restenosis in 1/5 of patients after stent implantation and appears to be associated with more intense coronary vasoreactivity.     

冠状动脉支架术后的胸部不适与再狭窄

目的 :了解冠状动脉支架术后胸部不适与再狭窄关系。方法 :选择接受冠状动脉支架术并在 6个月内进行了冠状动脉造影检查的 186例患者 ,对术后胸部不适和无胸部不适患者进行冠心病易患因素和术后再狭窄比较。结果 :胸部不适和无胸部不适者术后支架内再狭窄的百分率分别为 2 1.4 %和 15 .2 % ,两组的再狭窄率差异无显著性意义。结论 :冠状动脉支架术后的胸部不适除与再狭窄有关外 ,可能与血管内皮功能紊乱及血管的反应性有关。     

Sirolimus-eluting stent implantation for unprotected left main coronary artery stenosis: comparison with bare metal stent implantation

OBJECTIVES: This study was designed to compare the clinical and angiographic outcomes of sirolimus-eluting stent (SES) and bare metal stent (BMS) implantation for unprotected left main coronary artery (LMCA) stenosis. BACKGROUND: The safety and effectiveness of SES implantation for unprotected LMCA stenosis have not been ascertained. METHODS: Elective SES implantation for de novo unprotected LMCA stenosis was performed in 102 consecutive patients with preserved left ventricular function from March 2003 to March 2004. Data from this group were compared to those from 121 patients treated with BMS during the preceding two years. RESULTS: Compared to the BMS group, the SES group received more direct stenting, had fewer debulking atherectomies, had a greater number of stents, had more segments stented, and underwent more bifurcation stenting. The procedural success rate was 100% for both groups. There were no incidents of death, stent thrombosis, Q-wave myocardial infarction (MI), or emergent bypass surgery during hospitalization in either group. Despite less acute gain (2.06 +/- 0.56 mm vs. 2.73 +/- 0.73 mm, p < 0.001) in the SES group, SES patients showed a lower late lumen loss (0.05 +/- 0.57 mm vs. 1.27 +/- 0.90 mm, p < 0.001) and a lower six-month angiographic restenosis rate (7.0% vs. 30.3%, p < 0.001) versus the BMS group. At 12 months, the rate of freedom from death, MI, and target lesion revascularization was 98.0 +/- 1.4% in the SES group and 81.4 +/- 3.7% in the BMS group (p = 0.0003). CONCLUSIONS: Sirolimus-eluting stent implantation for unprotected LMCA stenosis appears safe with regard to acute and midterm complications and is more effective in preventing restenosis compared to BMS implantation.     

Incomplete stent apposition in a left main bifurcated lesion after kissing stent implantation

We present the case of a 75-year-old female who developed restenosis after the deployment of kissing sirolimus-eluting stents at the left main coronary artery (LMCA) bifurcation. Restenosis occurred at the left circumflex (LCx) artery ostium, where a stent deployed from the LMCA to the LCx arteries overlapped another stent deployed from the LMCA to the left anterior descending (LAD) artery. We investigated the stent expansion and deformation after kissing stent implantation using a phantom three-dimensional model depicting a LMCA bifurcation. Stent overlap was detected at the distal LMCA whether the LAD stent was positioned over the left circumflex (LCx) stent or vice versa. Stent overlap created a gap beneath the overlapped portion of the stent. Thus, we found that kissing stent implantation using different-sized stents produced compression of the LCx stent at the distal LMCA. Incomplete stent apposition caused by stent overlap and stent deformation is thought to be the main mechanism for restenosis after kissing stent implantation procedures.     

Contemporary stent treatment of coronary bifurcations.

Treatment of coronary bifurcation lesions represents a challenging area in interventional cardiology. The introduction of drug-eluting stents (DES) reduced restenosis in the main branch (MB). However, restenosis at the ostium of the side branch (SB) remains a problem. Although stenting the MB with provisional SB stenting seems to be the prevailing approach, in the era of DES various two-stent techniques emerged (crush) or were re-introduced (V or simultaneous kissing stents, crush, T, culottes, Y, skirt) to allow stenting in the SB when needed. This review describes in detail various techniques used for implantation of two stents by intention to treat.     

A randomized comparison of balloon angioplasty and stent implantation in the percutaneous treatment of coronary bifurcations

OBJECTIVE: A prospective randomized multicentre pilot trial, comparing stenting with balloon angioplasty as a treatment for coronary lesions, located in a bifurcation was performed. METHODS AND RESULTS: After balloon dilatation, with a < 30% residual stenosis in the main vessel and < 50% residual stenosis in the side branch, patients were randomized to stay in a "balloon-only" group or to stenting. The stents used were the AVE S 670 for the main vessel and the Bestent, if needed, for the side branch. The primary end point was the incidence of major adverse cardiac events (MACE) at 6 months, secondary end points were in-hospital MACE, acute angiographic results, use of materials and duration of the procedure. One hundred eleven patients were randomized: 55 in the balloon group, 56 in the stent group. No differences in MACE-rates were found at 6 months (22% versus 20%, p = 0.78). The target vessel revascularization rate was 16% in the balloon group and 12.5% in the stent group (p = 0.56). The acute angiographic results were significantly better in the stent group (residual stenosis 8% versus 26% [p < 0.05]). More materials were used, with a near doubling of the duration of the procedure in the stent group (p < 0.05). CONCLUSIONS: Although stenting resulted in better immediate angiographic results during percutaneous treatment of lesions located in a bifurcation, as compared to balloon angioplasty alone, clinical events were comparable in the two treatment arms.     

Fatal infection after rapamycin eluting coronary stent implantation

Septic complications after coronary stenting are extremely rare. The occurrence of cardiac related sepsis after rapamycin eluting stent deployment has not been previously reported. The potential role of drug eluting stents in locally blunting the innate response to bacterial agents is discussed.     

Short- and long-term outcomes of compromised side branches after Multi-Link stent implantation

The Multi-Link stent is superior to other stents in terms of low rates of restenosis and target vessel revascularization. However, few data exist regarding short- and long-term outcomes for side branches after stenting. We evaluated short and long clinical outcomes and angiographic predictors of side-branch occlusion after the deployment of 137 Multi-Link stents. Thirty-four (25%) of the 137 side branches occluded immediately after stenting. We attempted reangioplasty for the side branches and our success rate was 85%. The incidence of side branches with intrinsic ostial disease was more than 50% before stenting and origination from the stented midsegment was a powerful angiographic predictor of side-branch occlusion. Side-branch patency is well maintained long-term. The incidence of restenosis within and near the stented segment of the parent vessel was 19%, and the incidence of target vessel revascularization was 15%. We recommend the use of Multi-Link stents regardless of the presence of side branches in the vicinity of the stenosis. Received: October 4, 2001 / Accepted: December 22, 2001     

Restenosis rate after intravascular ultrasound-guided coronary stent implantation

This study was designed to test the hypothesis that patients fulfilling intravascular ultrasound (IVUS) criteria for optimal coronary stent implantation show a reduction in the restenosis rate at 6 months. IVUS guidance for stent dilation may be associated with faciliated stent implantation and an increased acute luminal gain, but it has not yet been determined, whether and to what extent this procedure is associated with a reduction in the restenosis rate. IVUS-guided optimization of Palmaz-Schatz stent placement was performed in 125 consecutive patients, 64 of whom fulfilled IVUS-criteria for optimal stent placement. Another 125 patients served as the non-IVUS control group. In 107 patients (86%) of the non-IVUS control group and 105 patients (84 %) of the IVUS group, angiographic follow-up was performed. The IVUS group of patients revealed a significantly lower restenosis rate of 20.9% as compared with 29.9% in the control group (P = 0.033). Patients that met IVUS criteria for optimal stent placement had a larger minimal lumen diameter immediately after stent implantation (3.13 ± 0.44 vs. 2.95 ± 0.47 mm; P = 0.045) and at 6-month follow-up (2.23 ± 0.78 vs. 1.87 ± 0.76 mm; P = 0.019) as well as a significantly lower restenosis rate (13.5% vs. 28.3%; P = 0.038) as compared with patients that did not fulfil these criteria. Our data suggest that patients fulfilling IVUS criteria for optimal stent placement demonstrate a reduced risk for the development of restenosis. Thus, IVUS investigation identifies factors predictive of restenosis after coronary stent placement. Cathet. Cardiovasc. Diagn. 44:380–386, 1998. © 1998 Wiley-Liss, Inc.