Technical Complications of Coronary Bifurcation Percutaneous Interventions

Coronary bifurcation percutaneous interventions (PCI) comprise a challenging subset of patients with coronary artery disease. Beyond the well-known debate about single versus double stent strategies, which have different outcomes on mid- and long-term follow up, both strategies may be subject, although rarely, to several different technical complications, rarely reported in clinical trials, which need to be defined, classified, and understood by cardiovascular professionals involved in the management of patients with coronary bifurcation disease. The present paper aims to broaden the knowledge of the range of intraprocedural complications and relative treatment during PCI of coronary bifurcations.

Stenting strategy for coronary artery bifurcation with drug-eluting stents: a meta-analysis of nine randomised trials and systematic review

AIMS

The present study sought to compare angiographic and clinical outcomes of a simple strategy versus a complex strategy in patients with coronary bifurcation lesions undergoing drug-eluting stent implantation.

METHODS AND RESULTS

Medline, the Cochrane Library, and other internet sources were searched for randomised trials comparing simple strategy versus complex strategy for treating patients with bifurcation lesions. Nine eligible randomised trials including 2,569 patients were identified. The meta-analysis showed that cardiac death (odds ratio [OR]: 0.99, 95% confidence interval [CI]: 0.40- 2.41, p=0.98) and stent thrombosis (OR: 0.64, 95% CI: 0.31-1.34, p=0.24) were similar in the simple and the complex strategy. Compared with the complex strategy, the simple strategy was associated with a reduced risk of either early or follow-up myocardial infarction (OR: 0.53, 95% CI: 0.36-0.79, p=0.002; OR: 0.60, 95% CI: 0.43-0.86, p=0.01, respectively). The overall risks of side branch restenosis (OR: 1.44, 95% CI: 0.73-2.87, p=0.30), target lesion (OR: 1.72, 95% CI: 0.95-3.12, p=0.07) and target vessel revascularisation (OR: 1.59, 95% CI: 0.94-2.69, p=0.09) were comparable between the two groups. In the true bifurcation, with large side branches, and DK-crush subgroups, there were higher rates of reintervention seen in the simple strategy than in the complex strategy.

CONCLUSIONS

A complex strategy remains an optional treatment for patients with coronary bifurcation lesions without severe safety concerns. A complex strategy may be an optimal treatment for true bifurcation lesions with large side branches.

Overview of Technical and Cost Considerations in Complex Percutaneous Coronary Intervention

Complex percutaneous coronary intervention (PCI), encompassing an ever-expanding range of challenging lesion sets and patient populations, accounts for a significant proportion of PCI procedures being performed currently. Specific lesion types associated with lower rates of procedural success and higher rates of recurrence or major adverse cardiac events (MACE) include multivessel disease, unprotected left main coronary artery disease, fibrocalcific or undilatable lesions, chronic total occlusions, degenerated saphenous vein graft lesions, thrombotic lesions, and bifurcation disease. Validated tools and technical strategies currently exist to address most procedural scenarios encountered and should be familiar to the complex PCI operator. Anticipated clinical outcomes, projected resource utilization, and cost considerations should all factor into the decisions of when, how, and in whom to intervene.

Circumferential strut fracture as a mechanism of "crush" bifurcation restenosis

The "Crush" procedure is a 2-stent technique for the treatment of bifurcation lesions with greater rates of in-stent restenosis than the Culotte technique. In conclusion, we report a possible mechanism for this discrepancy in the case of severe Crush stent fracture with associated focal restenosis identified by postmortem microcomputed tomography and histologic examination.

Double versus single stenting for coronary bifurcation lesions: a meta-analysis

BACKGROUND

Several trials have addressed whether bifurcation lesions require stenting of both the main vessel and side branch, but uncertainty remains on the benefits of such double versus single stenting of the main vessel only.

METHODS AND RESULTS

We have conducted a meta-analysis of randomized trials including patients with coronary bifurcation lesions who were randomly selected to undergo percutaneous coronary intervention by either double or single stenting. Six studies (n=1642 patients) were eligible. There was increased risk of myocardial infarction with double stenting (risk ratio, 1.78; P=0.001 by fixed effects; risk ratio, 1.49 with Bayesian meta-analysis). The summary point estimate suggested also an increased risk of stent thrombosis with double stenting, but the difference was not nominally significant given the sparse data (risk ratio, 1.85; P=0.19). No obvious difference was seen for death (risk ratio, 0.81; P=0.66) and target lesion revascularization (risk ratio, 1.09; P=0.67).

CONCLUSIONS

Stenting of both the main vessel and side branch in bifurcation lesions may increase myocardial infarction and stent thrombosis risk compared with stenting of the main vessel only.

Hydrogen peroxide enhances osteopontin expression and matrix metalloproteinase activity in aortic vascular smooth muscle cells

1. Restenosis after percutaneous coronary intervention (PCI) is a major clinical complication. However, the underlying mechanisms remain poorly understood. The present aim of the present study was to test the hypothesis that reactive oxygen species (ROS) enhance osteopontin (OPN) expression and increase matrix metalloproteinase (MMP)-2 activity (two major factors that contribute to restenosis) in aortic vascular smooth muscle cells (VSMC), thus facilitating restenosis. 2. Primary cultured rat aortic VSMC were exposed to different concentrations (10, 50 and 100 micromol/L) of H(2)O(2). The expression of OPN mRNA and protein was determined by reverse transcription-polymerase chain reaction and Western blotting, respectively. The activity of MMP-2 was determined by gelatin zymography. 3. The expression of OPN mRNA and protein in VSMC was enhanced by H(2)O(2) in a dose-dependent manner. In addition, H(2)O(2) at all concentrations tested (which are comparable to those seen in diabetic vascular tissues) significantly increased MMP-2 activity in VSMC. 4. Because vascular ROS production is significantly increased in patients with ischaemic disease and OPN and MMP-2 have been shown to play critical role in restenosis, the results of the present study strongly suggest that a ROS-initiated and OPN- and MMP-2-mediated signalling pathway may play an important role in accelerated restenosis after PCI in patients with ischaemic disease. Therefore, the H(2)O(2)-OPN/MMP-2 system may be a new therapeutic target in reducing restenosis in patients undergoing PCI.