Comparison of the efficacy of direct coronary stenting with sirolimus-eluting stents versus stenting with predilation by intravascular ultrasound imaging (from the DIRECT trial)

Does direct stenting with drug-eluting stents improve outcome? A meta-analysis of 10,900 patients

OBJECTIVES

The aim of this study is to summarize the outcomes of patients undergoing direct stenting (DS) with drug-eluting stents (DES) compared to those who underwent balloon predilatation.

BACKGROUND

DS has been associated with improved outcomes in the bare-metal stent era. Although DS with DES implantation has been increasingly adopted in clinical practice, its safety and effectiveness remain controversial.

METHODS

The search criteria identified 546 studies in the Medline/PubMed, Cochrane, and EMBASE databases from 2001 to July 2014. From these, seven studies totaling 10,900 patients were selected. Summarized estimates [odds ratio (OR) and 95% confidence intervals] were obtained using a random-effects model. The primary outcomes were a composite of major adverse cardiac events (MACE), including all-cause death, myocardial infarction (MI), and repeat revascularization. The secondary outcomes included a composite of death and MI and the rates of target lesion revascularization (TLR).

RESULTS

Overall, 4101 (38%) and 6799 (62%) patients underwent DS with DES and balloon pre-dilatation, respectively. DS with DES reduced the likelihood of MACE (OR: 0.81 [0.71-0.93]). Additionally, DS with DES was associated with reduced rates of death/MI (OR: 0.76 [0.62-0.92]), and TLR (OR: 0.66 [0.44-0.98]).

CONCLUSIONS

DS with DES is safe and may be associated with better outcomes in selected patients. © 2016 Wiley Periodicals, Inc.

Serial endovascular assessment of polytetrafluoroethylene-covered stent: Capabilities and limitations of intravascular imaging modalities affected by a temporal factor

A 47-year-old male who previously underwent coronary bypass graft surgery was transferred to our hospital for treatment of bare metal in-stent restenosis (ISR) of severely calcified left main (LM) coronary lesion. During a repeat coronary intervention, LM coronary perforation occurred after rotational atherectomy followed by balloon dilatation. Hemostasis was successfully achieved by implantation of a single polytetrafluoroethylene (PTFE)-covered stent. Although intravascular ultrasound (IVUS) and optical coherence tomography (OCT) were documented, any additional information was not obtained except stent expansion. Routine 6-month follow-up angiography revealed no findings of restenosis. Three representative imaging modalities, IVUS, OCT, and angioscopy were applied to visualize and differentiate any structures within the PTFE-covered stent. Intravascular findings included, (1) vascular structures outside the covered stent could be observed sufficiently by both IVUS and OCT at this time that could not be seen at all just after implantation, (2) neointimal hyperplasia distributed dominantly at both stent edges, and (3) in-stent micro thrombi still existed even 6 months after implantation. Intravascular findings of PTFE-covered stent may vary between the observational periods. Furthermore, vascular healing process of this special stent may be different from those of non-covered mesh stents. <Learning objective: Even with the use of IVUS and OCT, it may be difficult to evaluate apposition of PTFE-covered stent just after implantation. However, it could be visualized as being sufficiently similar to the other common stents at 6-month follow-up. Unique longitudinal NIH distribution (bilateral edge dominant) was evaluated, and existence of micro thrombi within PTFE-covered stent even at 6 months.>.

Outcomes in patients undergoing multivessel percutaneous coronary intervention using sirolimus-eluting stents: a report from the e-SELECT registry

AIMS

Performing percutaneous coronary intervention (PCI) to multiple coronary lesions during the same procedure has potential economic and social advantages. However comprehensive outcome data of real world practice in a large population is limited. We aimed to compare short- and long-term outcomes between patients with multivessel coronary artery disease who either underwent single- or multivessel PCI within the e-SELECT registry.

METHODS AND RESULTS

The e-SELECT registry combines data collected at 320 medical centres in 56 countries where patients received CYPHER Select® or CYPHER Select® Plus sirolimus-eluting stent (SES). Rates of myocardial infarction and major adverse cardiac event (MACE) (defined as any death, myocardial infarction or target lesion revascularisation) were compared between patients undergoing single-vessel versus multivessel PCI. A total of 15,147 patients who satisfied the inclusion criteria were included in the e-SELECT registry. Two thousand two hundred and seventy-eight (2,278) subjects (15%) underwent multivessel PCI and 12,869 (85%) had single-vessel PCI. The mean age was higher in the multivessel PCI group (63 vs. 62 years, p<0.001) and there was a higher prevalence of diabetes mellitus (32.4 vs. 30.0%, p=0.02). Lesions were more complex in the single-PCI group while pre- and post-dilatation were less common in the multivessel PCI group. Myocardial infarction within the first 30 days post PCI was more common in the multivessel PCI group (1.9 vs. 0.8%, p<0.001) and most of the infarctions were periprocedural (1.3 vs. 0.6%, p=0.001). Mortality and myocardial infarction at one-year were higher in the multivessel PCI group resulting in a significantly higher MACE (6.1 vs. 4.6%, p=0.005).

CONCLUSIONS

Overall procedural and one year outcomes were excellent for both single- and multivessel procedures. However despite lower lesion complexity, performing multivessel PCI was associated with higher rates of periprocedural myocardial infarction and MACE when compared to single-vessel PCI in the e-SELECT registry.

Impact of different re-stenting strategies on expansion of a drug-eluting stent implanted to treat bare-metal stent restenosis

We used intravascular ultrasound (IVUS) to compare the expansion of drug-eluting stents (DES) implanted to treat bare-metal stent (BMS) restenosis after 3 common re-stenting strategies. A total of 80 consecutive BMS restenotic targets were re-stented either directly (n = 30, group 1) or after low-pressure (<8 atm) pre-dilation with an undersize regular balloon (n = 16, group 2) or after high-pressure (>12 atm) pre-dilation with a semicompliant balloon the same or greater diameter as the original BMS diameter (n = 34, group 3). More patients from groups 2 and 3 had diabetes mellitus. The targets in group 1 were more proximal and focal. Lesions from groups 2 and 3 were more severe. The size and deployment pressure of the DESs and the achieved angiographic results were all similar. The post-intervention minimum stent area and the percentage of expansion of DES (minimum stent area/distal reference lumen area x 100%) were, however, both significantly larger in group 3 (6.4 +/- 1.5 mm(2) in group 3 vs 5.6 +/- 1.6 mm(2) in group 1 vs 4.4 +/- 1.4 mm(2) in group 2, p <0.001; and 88 +/- 30% in group 3 vs 74 +/- 14% in group 1 vs 73 +/- 23% in group 2, p = 0.021). A post-intervention minimum stent area <5.0 mm(2) was seen in only 3 lesions in group 3 (8.8%) versus 14 in group 1 (46.7%) and 11 in group 2 (68.8%; adjusted odds ratio 0.11, 95% confidence interval 0.03 to 0.38, p <0.001). Overall, the acute lumen gain was mainly from BMS re-expansion; however, the BMS volume increased the most in group 3 (p <0.001). In conclusion, high-pressure pre-dilation leads to superior post-intervention expansion of DESs implanted to treat BMS restenosis, regardless of the original expansion because of the greater BMS re-expansion.

Functional result following direct coronary artery stenting with drug eluting stents in chronic stable angina is similar to stenting after balloon predilatation

BACKGROUND

The safety and efficacy of direct coronary artery stenting without predilatation using drug eluting stents has not been firmly established. Concerns have been raised that this technique may be associated with increased risk of immediate and short term complications.

METHODS

68 consecutive patients with chronic stable angina and angiographically proven single vessel disease were randomised to undergo either direct coronary artery stenting or stenting after balloon predilation. All patients underwent Pressure Wire directed percutaneous coronary intervention (PCI) and drug eluting stents were deployed. Pre and post-PCI fractional flow reserve (FFR) was assessed following administration of intravenous adenosine. Post-procedure troponin I (TNI) and creatine kinase-MB (CK-MB) were compared. 51 of the 68 patients successfully completed a 6 month treadmill exercise test.

RESULTS

There were no significant differences in the demographic, risk factor or angiographic profiles between the two groups except for hyperlipedemia and statin therapy. Drug eluting stents were deployed in all patients. Majority of the lesions were relatively simple (all lesions were either type A or B1). The pre-procedure FFR [mean(SD)]was marginally lower in the pre-dilatation group compared to the direct stenting group [0.57(0.17) versus 0.64(018); p=0.04]. The post-procedure FFR was similar in both groups [0.97(0.05) versus 0.98(0.03); p=0.26]. There was no difference in the post-procedure rise of either TNI or CK-MB in both groups. At 6 months, no major adverse cardiac events (death, MI or revascularisation) were observed in all patients. A positive exercise test was seen in 5 patients (10%) and there was no difference between the two groups.

CONCLUSION

A strategy of direct stenting of appropriate coronary lesions with drug eluting stents in patients with chronic stable angina is associated with similar functional results as balloon predilatation followed by stenting.

Intravascular ultrasound findings in ENDEAVOR II and ENDEAVOR III

The results of 2 randomized controlled trials of the Endeavor zotarolimus-eluting stent (ZES; Medtronic Vascular, Santa Rosa, CA) were recently reported: ENDEAVOR II, in which the Endeavor stent was compared with the Driver bare metal stent (BMS; Medtronic Vascular), and ENDEAVOR III, in which the Endeavor stent was compared with the first-generation Cypher sirolimus-eluting stent (SES; Cordis Corporation, Miami Lakes, FL). To examine in detail the vascular responses to the Endeavor stent, serial intravascular ultrasound (IVUS) analyses were performed in subsets of patients in the 2 trials at baseline and 8-month follow-up. The investigators report results for various IVUS parameters and compare those with published results for the first-generation SES and paclitaxel-eluting stent (PES). The ZES demonstrated significantly improved effectiveness and equivalent safety compared with the BMS in ENDEAVOR II. Although the ZES seems to be slightly less effective at inhibiting intimal hyperplasia than the SES and PES, early results are indicative of an acceptable safety profile. This finding may be due in part to the relatively complete and uniform neointimal coverage associated with the ZES.

Detailed intravascular ultrasound analysis of Zotarolimus-eluting phosphorylcholine-coated cobalt-chromium alloy stent in de novo coronary lesions (results from the ENDEAVOR II trial)

Zotarolimus-eluting phosphorylcholine-coated cobalt-chromium alloy Driver stents (ZES) demonstrated significant reductions in target lesion revascularization rate with few apparent adverse events compared with bare metal stents (BMS; uncoated Driver stents) in a prospective, multicenter, double-blind, randomized controlled trial in de novo coronary lesions. The aim of this study was to examine detailed vascular responses to ZES compared with BMS using serial intravascular ultrasound analysis. A total of 343 patients (ZES n = 178, BMS n = 165) were enrolled in this formal, prespecified intravascular ultrasound substudy of the Randomized Controlled Trial to Evaluate the Safety and Efficacy of the Medtronic AVE Zotarolimus-Eluting Driver Coronary Stent in de Novo Native Coronary Artery Lesions (ENDEAVOR II), a prospective, multicenter, double-blind, randomized controlled trial to compare ZES and BMS in de novo native coronary artery lesions. Quantitative and qualitative intravascular ultrasound analyses were performed postprocedurally and at 8-month follow-up in stented and reference segments. ZES showed significantly less neointima, with a larger lumen than BMS at 8 months (percentage neointimal volume 17.6 +/- 10.1% vs 29.4 +/- 17.2%, p <0.0001; maximum percentage neointimal area 32.9 +/- 13.0% vs 47.6 +/- 18.6%, p <0.0001; minimum luminal area 4.9 +/- 1.6 vs 4.0 +/- 1.7 mm(2), p <0.0001) and no unfavorable edge effect. In the 18-mm single stents, ZES showed evenly inhibited neointima compared with BMS. Neither persistent stent-edge dissection nor late-acquired incomplete stent apposition was observed in either group. In conclusion, ZES showed evenly inhibited neointima with no apparent adverse vascular response in stented and reference segments at 8 months compared with BMS.

Direct stenting limits sirolimus-eluting stent edge neointimal thickening

OBJECTIVE

The use of sirolimus eluting stent (SES) has strongly limited the incidence of in-stent restenosis that still remains a problem at the stent edge. The aim of this study was to analyze the neointimal thickening after implantation of SES and to assess the influence of the stent implantation procedure on the neointimal thickening in the in-stent segment and at the edge of the stent in an ex-vivo model of stented human artery.

METHODS

Both balloon expandable SES and the corresponding bare metal stent (BMS) were used in a model of human mammary artery culture. Stents were implanted either directly or after predilatation (10 atm, 60 seconds) and analysis of arterial segments were performed at 28 days poststenting. Cell proliferation and neointimal thickening were assessed by immunohistochemistry, western blotting, and histomorphometry, both in the in-stent segment and at the edge of the stent. Neointimal thickening was expressed as the ratio ([neointimal area/neointimal area + media area]).

RESULTS

The in-stent neointimal thickening was dramatically inhibited in the SES group compared with the BMS group whatever the stenting technique was (predilatation: 0.22 +/- 0.05 vs 0.30 +/- 0.10; P < .04; direct stenting 0.16 +/- 0.04 vs 0.30 +/- 0.13; P <.01). This effect of SES was associated with a smallest expression of the small G protein RhoA and an increase of p27kip expression. In the BMS group, predilatation and direct stenting gave similar in-stent neointimal thickening. In contrast, in the SES group, in-stent neointimal thickening was significantly reduced when direct stenting was performed (0.16 +/- 0.04 [direct stenting] vs 0.22 +/- 0.05 [predilatation], P < .03). At the stent edge, a similar neointimal thickening was observed with both type of stent when predilatation was performed on the entire segment of the artery. Direct stenting significantly reduced the neointimal thickness at the stent edge when SES where used (0.06 +/- 0.01 [direct stenting] vs 0.19 +/- 0.06 [predilatation]; P < .001) but not in the BMS group.

CONCLUSION

These results confirm the efficiency of sirolimus released form SES to inhibit RhoA expression and to increase p27kip level in the arterial wall and show the benefit of direct stenting to limit the edge effect with SES.