Nicola Corvaja

Results and Long-Term Predictors of Adverse Clinical Events After Elective Percutaneous Interventions on Unprotected Left Main Coronary Artery

Background—The safety and efficacy of percutaneous coronary intervention of de novo lesions in unprotected left main coronary arteries remains an unresolved issue. Methods and Results—We analyzed 67 consecutive patients treated with the following devices: 39 with stents, 12 with rotational atherectomy plus stents, 13 with directional coronary atherectomy plus stents (a total of 64 patients were treated with stents), and 3 patients with directional coronary atherectomy only. The reference vessel size was 3.78±0.73 mm and lesion length was 6.6±3.0 mm. In-hospital complications were 2 coronary artery bypass grafts (CABGs) (3.0%), 2 Q-wave myocardial infarctions (MIs) (3.0%), and 3 non-Q-wave MIs (4.5%); there were no deaths. The estimated cardiac survival at 3 years was 91%. The cardiac mortality rate was higher in patients with Parsonnet score >15 versus ≤15 (21.4% versus 4.2%, P =0.02) at 3 years. The independent covariate of cardiac death was preserved left ventricular ejection fraction; for combined cardiac events (cardiac death, MI, repeat revascularization) it was large reference vessel size. Follow-up angiography at 5±2 months in 85% of eligible patients revealed 31.4% restenosis. Extending the follow-up to 31±23 months (19 patients with follow-up beyond 3 years) the cumulative event rates were 11 deaths (16.4%), 8 of them cardiac (11.9%), 2 (3.0%) MI, and 16 (23.9%) repeat revascularizations (CABG in 5 patients). Conclusions—Elective percutaneous coronary intervention of de novo lesions in left main coronary arteries is feasible, with low procedural risk. The long-term follow-up revealed a high rate of angiographic restenosis and repeat revascularization, with a relatively high incidence of cardiac death. Reference vessel size and left ventricular function are the most important predictors of favorable follow-up.

MODIFIED T-STENTING TECHNIQUE WITH CRUSHING FOR BIFURCATION LESIONS: IMMEDIATE RESULTS AND 30-DAY OUTCOME

We report a new stenting technique employed in 20 consecutive patients to treat true bifurcation lesions using the Cypher stent (Cordis, Warren, NJ). Both stents are advanced at the site of the bifurcation. The proximal marker of the side‐branch stent must be situated in the main branch at a distance of 4–5 mm proximal to the carina of the bifurcation and the main branch stent must cover the bifurcation as well as the protruding segment of the side‐branch stent. The side‐branch stent is deployed first and balloon and wire are removed. The stent deployed in the main branch completely covers and crushes the protruding segment of the side branch stent against the vessel wall of the main branch. Following main‐ and side‐branch predilatation, stents were successfully deployed in all lesions. Final kissing balloon inflation was performed in seven patients. Two patients had in‐hospital myocardial infarction and one patient underwent in‐hospital re‐PTCA due to a dissection distal to a stent. No other major adverse cardiac events were observed in‐hospital and during 1‐month clinical follow‐up. Treatment of bifurcation lesions using crushing stent technique is feasible with acceptable rate of procedural complications. Angiographic follow‐up is necessary to prove the advantage of this specific technique to give complete coverage of the ostium of the side branch with a drug‐eluting stent. Catheter Cardiovasc Interv 2003;60:145–151.

In-Stent Restenosis in Small Coronary Arteries Impact of Strut Thickness

UNLABELLED OBJECTIVES; We sought to evaluate whether strut thickness may impact the restenosis rate after stent implantation in small coronary arteries. BACKGROUND Small vessel size (<3.0 mm) is an independent risk factor for the occurrence of in-stent restenosis. It has been reported that vessel damage induced during stent deployment is an important factor in restenosis. METHODS From our database, we selected all patients who had successful stenting in small native vessels, with angiographic follow-up available, between March 1996 and April 2001. The strut was defined as thin when <0.10 mm and thick when > or = 0.10 mm. According to these criteria, we identified two subgroups: a thin group and a thick group. RESULTS A total of 821 (57%) of the 1,447 patients had angiographic follow-up available and were included in the analysis. The thin group included 400 patients with 505 lesions. The thick group included 421 patients with 436 lesions. The restenosis rate was 28.5% in the thin group and 36.6% in the thick group (p = 0.009; odds ratio [OR] 1.44, 95% confidence interval [CI] 1.09 to 1.90). The study group was classified into three subgroups according to the reference vessel diameter: < or = 2.50 mm, 2.51 to 2.75 mm and 2.76 to 2.99 mm. Strut thickness influenced the restenosis rate only in the subgroup with a reference vessel diameter between 2.76 and 2.99 mm, with rates of 23.5% in the thin group and 37% in the thick group (p = 0.006). By logistic regression analysis, predictors of restenosis were stent length (OR 1.03, 95% CI 1.01 to 1.04; p = 0.001), strut thickness (OR 1.68, 95% CI 1.23 to 2.29; p = 0.001) and diabetes mellitus (OR 2.10, 95% CI 1.21 to 3.68; p = 0.007). CONCLUSIONS This study supports that strut thickness is an independent predictor of restenosis in coronary arteries with a reference diameter of 2.75 to 2.99 mm.

First Clinical Experience With a Paclitaxel Derivate–Eluting Polymer Stent System Implantation for In-Stent Restenosis Immediate and Long-Term Clinical and Angiographic Outcome

Background—It has been shown that antiproliferative drugs such as paclitaxel lower the amount of intimal hyperplasia after stent implantation. We report the first clinical experience of 7-hexanoyltaxol (QP2)–eluting polymer stent system (QuaDS) implantation for in-stent restenosis. Methods and Results—Fifteen consecutive patients with elective indication to percutaneous coronary intervention for in-stent restenosis were treated with the QuaDS-QP2 stent implantation. The QuaDS-QP2 stent was successfully implanted in all but 2 target lesions. In one lesion, the restenotic segment could not be completely covered by the stent, and in another lesion, a bare metal stent was implanted distally to the QuaDS-QP2 stent. One patient suffered from postprocedural non–Q-wave myocardial infarction (NQWMI). No other adverse events were observed during hospital stay. Six- and 12-month angiographic and clinical follow-up was scheduled for all patients. At 6 months, 3 patients had target lesion revascularization (20%). Two patients had restenosis (13.3%); one experienced restenosis in a gap between 2 drug-eluting stents, and the other had stent occlusion leading to NQWMI. Minimal intimal hyperplasia was observed in all the segments covered by drug-eluting stents (late loss=0.47±1.01 mm with a loss index=0.17±0.39). At 12 months, 1 patient suffered from NQWMI, and 8 of 13 patients (61.5%) had angiographic restenosis (late loss=1.36±0.94 mm with a loss index=0.62±0.44). Conclusion—This first experience with QuaDS-QP2 stent implantation for in-stent restenosis revealed minimal intimal hyperplasia at the 6-month follow-up. However, the antiproliferative effect was not maintained at the 12-month follow-up, resulting in delayed occurrence of angiographic restenosis.

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenoses and comparison with fractional flow reserve.

The functional significance of coronary artery stenoses of intermediate severity is important in determining strategy in patient care. Intravascular ultrasound (IVUS) is often used to evaluate coronary stenosis severity. However, at present, few data are available about the role IVUS in the assessment of functional significance of intermediate lesions. Myocardial fractional flow reserve (FFR) <0.75 is a reliable index of a functionally severe coronary stenosis. In 53 lesions we assessed (1) by pressure wire: FFR (index of functional significance), and (2) by IVUS: minimal lumen cross-sectional area (MLA, square millimeters), minimal lumen diameter (MLD, millimeters), lesion length (millimeters), and percent area stenosis at the lesion site. By regression analysis, percent area stenosis and lesion length had a significant inverse correlation with FFR (r = -0.58, p <0.001, r = -0.41, p <0.004, respectively). MLD and MLA showed a significant positive relation with FFR (r = 0.51, p <0.001, r = 0.41, p <0.004, respectively). By using a receiver operating characteristic (ROC) curve, we identified a percent area stenosis > 70% (sensitivity 100%, specificity 68%), a MLD < or = 1.8 mm (sensitivity 100%, specificity 66%), a MLA < or =4.0 mm2 (sensitivity 92%, specificity 56%), and a lesion length of >10 mm (sensitivity 41%, specificity 80%) to be the best cut-off values to fit with a FFR <0.75. The combined evaluation of both percent area stenosis and MLD made the IVUS examination more specific (sensitivity 100%, specificity 76%). In 53 intermediate coronary lesions found by angiography, IVUS area stenosis >70%, MLD < or =1.8 mm, MLA < or =4.0 mm2, and lesion length > 10 mm reliably identified functionally critical intermediate coronary stenoses.

Multicenter evaluation of carotid artery stenting with a filter protection system

OBJECTIVES The aim of this study was to evaluate the feasibility and safety of carotid artery stenting (CAS) with a filter protection system. BACKGROUND Neurologic events linked to the embolization of particulate matter to the cerebral circulation may complicate CAS. Strategies designed to capture embolic particles during carotid intervention are being evaluated for their efficacy in reducing the risk of these events. METHODS Between September 1999 and July 2001, a total of 162 patients (164 hemispheres) underwent CAS with filter protection (NeuroShield, MedNova Ltd., Galway, Ireland) according to prospective protocols evaluating the filter system at three institutions. RESULTS Angiographic success was achieved in 162 of the procedures (99%) and filter placement was successful in 154 (94%) procedures. Carotid access was unsuccessful in two cases (1%) and filter placement in eight cases (5%). Of the latter, five procedures were completed with no protection and three were completed using alternative protection devices. On an intention-to-treat basis, the overall combined 30-day rate of all-stroke and death was 2% (four events: two minor strokes and two deaths). This includes one minor stroke in a patient with failed filter placement and CAS completed without protection. There was one cardiac arrhythmic death and one death from hyperperfusion-related intracerebral hemorrhage. There were no major embolic strokes. CONCLUSIONS Carotid artery stenting with filter protection is technically feasible and safe. Early clinical outcomes appear to be favorable and need to be confirmed in a larger comparative study.

Treating chronic total occlusions using subintimal tracking and reentry: The STAR Technique

Successful recanalization of coronary total occlusions (CTOs) remains an area where improvements are needed. We propose an approach similar to the one utilized in treating some peripheral artery occlusions and aimed to create a subintimal dissection with distal reentry. A 0.014′ hydrophilic wire with a J‐configuration is utilized for this purpose. We applied this technique to CTO of native coronaries in 31 patients where previous attempts failed in 21 of them (67%). The right coronary artery (RCA) was the index vessel in 87% of patients. Recanalization of the vessel and of most of distal branches was achieved in 21 patients; patency of at least one major distal branch was achieved in 9 patients. Drug‐eluting stents (DESs) were implanted in 53% of patients. Three patients had intraprocedural vessel perforation without consequences. Five patients (16%) had in‐hospital non‐Q‐wave myocardial infarction. No other adverse events occurred at a mean follow‐up of 5.1 ± 3.7 months except for one noncardiac death. Angiographic follow‐up was performed in 21 (67%) patients and 53% of them developed restenosis. Reintervention on the target vessel was performed in 11 patients (52%). Complete success with the procedure was originally obtained in 8 of the 10 patients who did not develop restenosis and in 8 of them DESs were originally implanted. This technique appears a promising approach to recanalize difficult total occlusions, particularly the ones localize on the RCA, which has the most important side branches located distally. Catheter Cardiovasc Interv 2005;64:407–411.

Preliminary Observations Regarding Angiographic Pattern of Restenosis After Rapamycin-Eluting Stent Implantation

Background—Restenosis after implantation of drug-eluting stents (DES) is a rare phenomenon, occurring more frequently peri-stent. Methods and Results—We evaluated the pattern of restenosis occurring after implantation of DES in unselected lesions. From April 15 to December 6, 2002, we treated 368 patients with 735 lesions by using 841 rapamycin-eluting stents (Cypher, Cordis, a Johnson & Johnson Company). Mean baseline lesion length was 17.48±12.19 mm, and mean stent length was 27.59±14.02 mm. Follow-up ischemia-driven angiography was performed in 24 patients. Eleven patients had angiographic restenosis (≥50% diameter stenosis) in 14 stented segments (stent and 5 mm proximal and distal to the stent). The pattern of restenosis in all 14 stented segments was focal, and in 6 of them it was multifocal, occurring inside the stents. Mean length of restenotic lesions was 5.62±1.90 mm, with a range from 2.54 to 8.44 mm. One multifocal restenosis involved also the distal stent margin. Intravascular ultrasound evaluation at follow-up, performed in 2 patients, showed significant lumen obstruction attributable to in-stent hyperplasia in both cases. Individual cases can be viewed in the Data Supplement. Conclusions—The pattern of restenotic lesions after rapamycin-eluting stent implantation was focal and mostly inside the stent.

Edge Restenosis After Implantation of High Activity 32P Radioactive β-Emitting Stents

Background—A high restenosis rate has been reported at the edges (“edge restenosis”) of 32P radioactive stents with an initial activity level of 3 to 12 μCi. This edge effect might be due to balloon injury and to a low dose of radiation at the stent margins. The aim of this study was to evaluate whether the implantation of 32P radioactive stents with a higher activity level (12 to 21 μCi) combined with a nonaggressive stent implantation strategy could solve the problem of edge restenosis. Methods and Results—We compared the results of lesions treated with single radioactive BX stents with an activity of 12 to 21 μCi (group 2, n=54 lesions) with the results of lesions treated by single radioactive BX stents with an initial activity level of 3 to 12 μCi (group 1, n=42 lesions). There were no procedural events. At the 6-month follow-up, no myocardial infarctions, deaths, or stent thromboses had occurred. Intrastent binary restenosis was 0% in group 1 versus 4% in group 2 (n=2, both at the ostium of the right...

Treatment of bifurcation lesions with two stents: one year angiographic and clinical follow up of crush versus T stenting

Objectives: To compare long term outcomes of the crush versus the T technique in bifurcation lesions. Design: 182 consecutive patients were identified who underwent percutaneous coronary interventions for bifurcation lesions with drug eluting stents between April 2002 and January 2004. Two techniques were used according to the operator’s discretion: crush (group C, n  =  121) or T (group T, n  =  61). Results: In-hospital outcome differed significantly between the two groups. Angiographic follow up was available for 142 (78%) patients. Groups C and T did not differ significantly regarding late loss (0.42 (0.39) mm v 0.34 (0.35) mm, p  =  0.52) and rate of restenosis (16.2% v 13.0%, p  =  0.80) in both the main and the side branch without final kissing balloon post-dilatation. However, when final kissing balloon post-dilatation was performed, group C had significantly lower late lumen loss (0.23 (0.21) mm v 0.37 (0.33) mm, p  =  0.02) and restenosis rate (8.6% v 26.5%, p  =  0.04) in the side branch. At one year’s clinical follow up, group C compared with group T had lower rates of target lesion revascularisation (14.0% v 31.1%, p  =  0.01) and target vessel revascularisation (16.5% v 32.8%, p  =  0.02). Conclusions: In non-selected bifurcation lesions treated with drug eluting stents, the restenosis rate remains relatively high in the side branch. Compared with the T stenting technique, crush stenting with kissing balloon post-dilatation is associated with a reduced rate of restenosis in the side branch.