Percutaneous revascularization of ostial saphenous vein graft stenoses

Risk assessment of slow or no-reflow phenomenon in aortocoronary vein graft percutaneous intervention

Slow or no-reflow phenomenon (SNR) complicates 10%-15% of cases of percutaneous intervention (PCI) in aortocoronary saphenous vein grafts (SVG). At present, there are no uniform, effective strategies to predict or prevent this common and potentially serious complication. The purpose of our study was to characterize variables correlated with the risk of SNR in SVG PCI in the era of stenting and glycoprotein IIb/IIIa receptor inhibitors. We identified 2,898 consecutive patients who had PCI, of whom 163 underwent PCI of at least one SVG. The clinical and angiographic characteristics of patients who developed SNR (SNR group) were compared with those who did not (no-SNR group). A total of 23 patients experienced SNR and 140 did not. Using a stepwise multivariate logistic regression analysis, four independent predictors for SNR were detected: probable thrombus (OR 6.9; 95% CI, 2.1-23.9; P = 0.001), acute coronary syndromes (OR 6.4; 95% CI, 2.0-25.3; P = 0.003), degenerated vein graft (OR 5.2; 95% CI, 1.7-16.6; P = 0.003), and ulcer (OR 3.4; 95% CI, 0.99-11.6; P = 0.04). The risk of developing SNR could be estimated according to the number of predictors found: low-grade risk (1%-10%) if < or = one variable was present, moderate risk (20%-40%) if two variables were present, and high risk (60%-90%) if three or more variables were present. We identified and quantified current risk factors for SNR and concluded that the risk of developing SNR during PCI in SVG can be predicted by simple clinical and angiographic variables obtained before PCI. This information may be useful when the risk of PCI has to be balanced against alternative strategies such as medical therapy or redo-bypass surgery or in the selection of those patients that will most benefit from the use of protection devices during PCI.

Comparison of debulking followed by stenting versus stenting alone for saphenous vein graft aortoostial lesions: immediate and one-year clinical outcomes

OBJECTIVES

We compared in-hospital and one-year clinical outcomes in patients undergoing debulking followed by stent implantation versus stenting alone for saphenous vein graft (SVG) aortoostial lesions.

BACKGROUND

Stent implantation in SVG aortoostial lesions may improve procedural and late clinical outcomes. However, the impact of debulking before stenting in this complex lesion subset is unknown.

METHODS

We studied 320 consecutive patients (340 SVG aortoostial lesions) treated with Palmaz-Schatz stents. Debulking with excimer laser or atherectomy was performed in 133 patients (139 lesions) before stenting (group I), while 187 patients (201 lesions) underwent stent implantation without debulking (group II). Procedural success and late clinical outcomes were compared between the groups.

RESULTS

Overall procedural success (97.6%) was similar between the groups. Procedural complications were also similar (2.2% for group I and 2.6% for group II). At one-year follow-up, target lesion revascularization (TLR) was 19.4% for group I and 18.2% for group II (p = 0.47). There was no difference in cumulative death or Q wave myocardial infarction between the groups. Overall cardiac event-free survival was similar (69% for group I and 68% for group II). By Cox regression analysis, the independent predictors of late cardiac events were final lumen cross-sectional area (CSA) by intravascular ultrasound (IVUS) (p = 0.001) and restenotic lesions (p = 0.01). Similarly, final IVUS lumen CSA (p = 0.0001) and restenotic lesions (p = 0.006) were found to predict TLR at one year.

CONCLUSIONS

These results suggest that, in most patients with SVG aortoostial lesions, debulking before stent implantation may not be necessary.

The importance of proteinuria as a determinant of mortality following percutaneous coronary revascularization in diabetics

OBJECTIVES

The aims of this study were to compare mortality and clinical events following percutaneous coronary intervention (PCI) between nondiabetics and diabetics with and without proteinuria.

BACKGROUND

Diabetics have increased rates of late myocardial infarction, repeat revascularization and mortality when compared with nondiabetics following PCI. Proteinuria is a marker for diabetic nephropathy and potentially a surrogate marker for advanced atherosclerosis. It is unknown if proteinuria is a predictor of outcome in diabetics following PCI.

METHODS

We performed an observational study of 2,784 patients who underwent PCI at the Cleveland Clinic between January 1993 and December 1995. There were 2,247 nondiabetics and 537 diabetics with urinalysis and follow-up data available (proteinuria n = 217, nonproteinuria n = 320). The diabetic proteinuria group was further prospectively stratified into low concentration (n = 182) and high concentration (n = 35). The end points were all-cause mortality and the composite end point of death, nonfatal myocardial infarction (MI) and need for revascularization.

RESULTS

The mean follow-up time was 20.2 months. The two-year mortality rate was 7.3% and 13.5% for nondiabetics and diabetics, respectively (p < 0.001). The two-year mortality rate was 9.1% and 20.3% for the nonproteinuria and proteinuria groups, respectively (p < 0.001). There was a graded increase in mortality comparing the diabetic group. The two-year mortality rate was 9.1%, 16.2% and 43.1% for the nonproteinuria, low concentration and high concentration groups, respectively (p < 0.001). The difference in survival between the nondiabetic and nonproteinuric diabetics was not significant (p = 0.8).

CONCLUSIONS

The presence of proteinuria is the key determinant of risk following PCI for diabetics. Diabetics without evidence of proteinuria have similar survival compared with nondiabetics.

Coronary artery stenting: indications and cost implications

The practice of coronary stenting is evolving rapidly, with new stent designs, deployment techniques, and adjunctive therapy. In many respects, clinical practice is changing in advance of the availability of supporting data. The consistent excellent angiographic result with stent deployment exceeds that achieved by any other previous interventional device, and the extent to which this accounts for the exponential increase in stent utilization cannot be accurately determined but is undoubtedly considerable. Controlled randomized trials have confirmed that stent deployment is superior to balloon angioplasty in certain lesion subsets or clinical scenarios. These include focal de novo native vessel lesions, lesions with late recoil after balloon angioplasty, acute closure after balloon angioplasty, and proximal left anterior descending coronary artery lesions. In addition, observational data is persuasive in focal coronary saphenous vein graft lesions and aorto-ostial lesions. On the other hand, the evidence supporting the use of stents strictly to improve on a suboptimal result, possibly the most frequent indication, is indirect and circumstantial. Stents are expensive, but it was anticipated that with the reduction in restenosis not only would they be cost-effective but also ultimately would reduce costs. This hope has not as yet been realized. However, there is little question that the introduction of intracoronary stents has been the most significant and exciting development since the introduction of percutaneous revascularization almost 20 years ago. It has revitalized the field.

Percutaneous transcatheter therapy of aorto-ostial stenoses

The treatment of native coronary and saphenous vein graft aorto-ostial stenoses with balloon angioplasty (PTCA) has been associated with lower procedural success rates, more frequent in-hospital complications and a greater likelihood of late restenosis when compared with PTCA of non-ostial stenoses. The advent of ablative technologies and intracoronary stents have significantly altered both early and late outcomes of percutaneous intervention for aorto-ostial disease. The optimal approach to this complex lesion subset often involves decalcification or tissue ablation followed by stent deployment. Improvements in currently available stent technology including enhanced radial force and visibility, reduced thrombogenicity, and the availability of shorter stent lengths, may also facilitate stent deployment and further improve outcomes following percutaneous transcatheter therapy for aorto-ostial stenoses.