Short-term outcome of stent implantation in saphenous vein grafts: predictors of distal embolization and restenosis

Predictors of periprocedural complications in patients undergoing percutaneous coronary interventions within coronary artery bypass grafts

BACKGROUND

During the first decade following the coronary bypass grafting, at least ten percent of the patients require percutaneous coronary interventions (PCI) due to graft failure. Saphenous vein grafts (SVG) are innately at a higher risk of periprocedural complications. The present study aimed to investigate predictors of periprocedural complications of PCI within coronary artery bypass grafts.

METHODS

This study analyzed data gathered in the Polish National Registry (ORPKI) between January 2015 and December 2016. Of the 221,195 patients undergoing PCI, data on 2,616 patients after PCI of SVG and 442 patients after internal mammary artery (IMA) were extracted. The dissimilarities in periprocedural complications between the SVG, IMA and non-IMA/SVG groups and their predictors were investigated.

RESULTS

Patients in the SVG group were older (p < 0.001), with a higher burden of concomitant disease and differing clinical presentation. The rate of de-novo lesions was lower, while restenosis was higher at baseline in the SVG (p < 0.001). The rate of no-reflows (p < 0.001), perforations (p = 0.01) and all periprocedural complications (p < 0.01) was higher in the SVG group, while deaths were lower (p < 0.001). Among the predictors of no-reflows, it was found that acute coronary syndromes (ACS), thrombectomy and past cerebral stroke, while the complications included arterial hypertension, Thrombolysis in Myocardial Infarction (TIMI) flow before PCI and thrombectomy.

CONCLUSIONS

Percutaneous coronary interventions of SVG is associated with increased risk of specific periprocedural complications. The ACS, slower TIMI flow before PCI and thrombectomy significantly increase the periprocedural complication rate in patients undergoing PCI of SVG.

Procedural results and distal embolization after saphenous vein graft stenting and angioplasty for in-stent restenosis of grafts

Saphenous vein graft (SVG) angioplasty is associated with frequent periprocedural complications due to distal embolization and a high risk of restenosis. The purpose of this single-center, retrospective study was to determine the distal embolization incidences and outcomes of stenting for SVG lesions and percutaneous angioplasty for in-stent restenosis of these SVGs. We studied 48 consecutive patients (mean age, 62 +/- 7 years, 92% men) who had prior CABG and underwent stent deployment to SVG lesions detected at our institution over a period of 4 years. Mean lesion length was 12.4 +/- 3.2 mm. The minimal lumen diameter increased from 0.7 +/- 0.3 mm to 3.2 +/- 0.4 mm after stenting. Distal embolization as no reflow/slow flow phenomenon occurred in 5 (10%) patients. Angiographic success was achieved in 98% of the patients. Procedural success was achieved in 96% of the patients. No reflow/slow flow phenomenon was observed, particularly in patients with acute coronary syndrome. During the follow-up, 11 patients (23%) had angiographic evidence of restenosis. Lesions were treated with balloon angioplasty and the minimal lumen diameter increased from 2.6 +/- 1.1 mm to 3.1 +/- 0.3 mm. The angiographic and procedural success rates were both 100%. There were no cases of "no" reflow/slow flow. Restenosis was particularly frequent in patients with diabetes mellitus, hypercholesterolemia, and acute coronary syndrome. Stent implantation in patients with de novo SVG lesions can be achieved with a high rate of angiographic and procedural success. The distal embolization risk is lower during angioplasty of in-stent restenosis lesions of SVGs compared to de novo SVG lesions.

Impact of the cross-sectional geometry of the post-deployment coronary stent on in-stent neointimal hyperplasia: an intravascular ultrasound study

To establish the relationship between the cross-sectional geometry of the post-deployment stent and the degree of in-stent neointimal hyperplasia (INH), intravascular ultrasound (IVUS) was used to examine cross-sections of the coronary arteries from 23 patients with coronary stents 6 months after implantation. Stent cross-sectional area (Sa) and stent perimeter (Sp) from 200 stent cross-sections, and the stent radius (Sr) and thickness of INH (Id) of 2,880 radial axes, were measured, and the mean degree of roundness (Rd) of stent cross-section was calculated for each stent as Rd=4piSa/Sp2. The degree of deformity (Df) of the stent cross-section was also calculated by comparing it with a hypothetical circle (the area of this hypothetical circle was equal to the Sa): Df=Sr/R, where R is the radius of the hypothetical circle. The area of INH was significantly larger in the Rd<0.87 group (n=84) than in the Rd> or =0.87 group (n=116) (3.83+/-1.26 vs 3.16+/-1.32 mm2, p<0.0005). There were significant differences in the thickness of INH among the 3 groups classified by the value of Df (Df<0.95: n=425, 0.21+/-0.12mm; 0.95< or =Df<1.05: n=2008, 0.29+/-0.15mm; Df> or =1.05: n=447, 0.34+/-0.15mm, overall p<0.0001). These data suggest that in-stent neointimal proliferation is more likely to occur in stented coronary arteries with a more oval than rounded cross-section, and particularly within the more pronounced and curved portion of the oval.