Therapeutic strategy for in-stent restenosis based on the restenosis pattern after drug-eluting stent implantation

Usefulness of coronary pressure measurement for functional evaluation of drug-eluting stent restenosis

Despite the widespread adoption of drug-eluting stent (DES) implantation, the optimal treatment of DES failures remains challenging. The present study evaluated the relation between quantitative angiography and the fractional flow reserve (FFR) in restenotic lesions after DES implantation and the efficacy of FFR in determining whether to treat these lesions. To assess their functional significance, the coronary pressure-derived FFR was measured in 50 DES restenotic lesions (49 patients). Additional intervention was performed in lesions with a FFR <0.8. Major adverse cardiac events were assessed at 12 months after the reintervention procedure. The mean percent diameter stenosis (%DS) was 58 ± 13%. Of the 50 lesions, 20 (40%) were deferred without additional intervention. The FFR and %DS had a negative correlation (r = -0.61, p <0.001). However, when only the lesions with diffuse-type restenosis (15 lesions) were analyzed, the degree of correlation decreased (r = -0.56, p = 0.12). Although most lesions (89%) with a %DS of ≥70 had significant functional ischemia, among 41 lesions with a %DS <70, only 20 (49%) had demonstrated functional patency. The incidence of adverse events during the 12 months of follow-up after FFR-guided treatment was 18.0% (23.3% in the FFR <0.80 group and 10.0% in FFR ≥0.80 group). In conclusion, a discrepancy was found between functional ischemia measured by the FFR and the angiographic %DS, in particular, in moderate- or diffuse-type restenotic lesions after DES implantation. The outcome of FFR-guided deferral in patients with DES in-stent restenosis seems favorable.

Late catch-up phenomenon associated with stent fracture after sirolimus-eluting stent implantation: incidence and outcome

OBJECTIVE

To examine the long-term outcome of the stent fracture (SF) and the potential predictive factors contributing to in-stent restenosis (ISR) in the fractured stent.

BACKGROUND

The SF is thought to be a higher risk of ISR in drug-eluting stent, although SF does not always develop ISR.

METHODS

The consecutive 1,228 de novo lesions in 1,079 patients who underwent sirolimus-eluting stents implantation and assessed by 8 months follow-up coronary angiography were retrospectively analyzed.

RESULTS

One hundred and seventeen SFs (9.5%) were identified in 100 patients and 22 (18.8%) SFs revealed ISR at the first follow-up. In addition, 16 (13.7%) developed new ISRs from 95 residual SFs without ISR prior to the second follow-up. Overall, 38 (32.5%) of all 117 SFs developed ISR, and 16 (42.1%) of 38 SFs occurred in a late phase beyond the first 8 months follow-up. A higher risk of ISR in the SF site was associated with the chronic total occlusion (ISR vs. no ISR: 34.2% vs. 16.5%, P = 0.0304), calcified lesions (55.3% vs. 34.2%, P = 0.0299), and correspondence 89.5% versus 43.0%, P < 0.0001 (SF site occurring at the original target lesion site) in the univariate analysis. The correspondence was identified as the only strong predictive factor for ISR at the SF site according to a multivariate logistic regression analysis (odds ratio 12.6, 95% confidence interval 3.82-53.5, P < 0.0001).

CONCLUSIONS

SF occurring at the site of the original target lesion was a strong independent predictor of ISR. This indicates the need for a careful, long-term follow-up in those situations, even when no significant ISR is initially detected.

Comparison of plain balloon and cutting balloon angioplasty for the treatment of restenosis with drug-eluting stents vs bare metal stents

BACKGROUND

The efficacy of cutting or plain balloon angioplasty (CBA or PBA) has not been analyzed for the treatment of drug-eluting stent (DES) restenosis vs bare metal stent (BMS) restenosis.

METHODS AND RESULTS

The 252 in-stent restenosis (ISR) lesions in 224 consecutive patients treated by CBA (n=167) or PBA (n=85) between July 2002 and December 2007 were analyzed. At 6-month angiographic and 12-month clinical follow-up, CBA and PBA showed similar efficacies: repeat-ISR (37.0% vs 37.8%, P=0.90), late loss (0.62+/-0.60 vs 0.61+/-0.47 mm, P=0.92), and target lesion revascularization (18.3% vs 22.4%, P=0.50). This comparable efficacy was maintained for treatment in the DES-ISR and BMS-ISR subgroups. However, target lesion-related myocardial infarction (n=9) occurred more frequently in the CBA than in the PBA arm (6.2% vs 0%, P=0.03), most of which developed early after ISR treatment (n=7; 54+/-26 days). Independent predictors of repeat-ISR were diffuse ISR and smaller pretreatment minimal lumen diameter, both of which might imply heavier plaque burden in the ISR group.

CONCLUSIONS

Plain or cutting balloon angioplasty for ISR seems to be comparable, as the angiographic or clinical endpoints were not affected by initial stent type but by parameters related to the plaque burden of the ISR lesion. However, CBA might be associated with higher risk of myocardial infarction than PBA, suggesting more attention to dual-antiplatelet therapy after its use for ISR.