Matteo Montorfano

Incidence and Predictors of Drug-Eluting Stent Thrombosis During and After Discontinuation of Thienopyridine Treatment

Background— The need for prolonged aspirin and thienopyridine therapy and the risk of stent thrombosis (ST) remain as drawbacks associated with drug-eluting stents. Methods and Results— A prospective observational cohort study was conducted between June 2002 and January 2004 on 3021 patients consecutively and successfully treated in 5389 lesions with drug-eluting stents. Detailed patient information was collected on antiplatelet therapy. We analyzed the incidence of ST throughout the 18-month follow-up period and its relationship with thienopyridine therapy. ST occurred in 58 patients (1.9%) at 18 months. Forty-two patients (1.4%) experienced the event within 6 months of stent implantation. Acute myocardial infarction (fatal or nonfatal) occurred in 46 patients (79%) and death in 23 patients (39%) with ST. The median interval from discontinuation of thienopyridine therapy to ST was 13.5 days (interquartile range 5.2 to 25.7 days) for the first 6 months and 90 days (interquartile range 30 to 365 days) between 6 and 18 months. On multivariable analysis, the strongest predictor for ST within 6 months of stenting was discontinuation of thienopyridine therapy (hazard ratio, 13.74; 95% CI, 4.04 to 46.68; P<0.001). Thienopyridine discontinuation after 6 months did not predict the occurrence of ST (hazard ratio, 0.94; 95% CI, 0.30 to 2.98; P=0.92). Conclusions— Discontinuation of thienopyridine therapy was the major determinant of ST within the first 6 months, but insufficient information is available to determine whether there is benefit in continuing a thienopyridine beyond 6 months.

Early and Mid-Term Results of Drug-Eluting Stent Implantation in Unprotected Left Main

Background—The safety and efficacy of percutaneous coronary intervention in unprotected left main (ULM) coronary arteries are still a matter of debate. Methods and Results—All consecutive patients who had a sirolimus-eluting stent (Cypher, Cordis, Johnson and Johnson Co) or a paclitaxel-eluting stent (Taxus, Boston Scientific) electively implanted in de novo lesions on unprotected left main were analyzed. Patients treated with a drug-eluting stent (DES) were compared with the historical group of consecutive patients treated with bare metal stent (BMS). Eighty-five patients were treated with DES; 64 had BMS implantation. Patients treated with DES had lower ejection fractions (51.1±11% versus 57.4±13%, P=0.002) and were more often diabetics (21.2% versus 10.9%, P=0.12) with more frequent distal left main involvement (81.2% versus 57.8%, P=0.003). Furthermore, in the DES group, smaller vessels (3.33±0.6 versus 3.7±0.7 mm, respectively; P=0.0001) with more lesions (2.94±1.6 versus 2.25±1.3, P=0.004) and vessels (2.03±0.69 versus 1.8±0.72, P=0.05) were treated with longer stents (24.3±12 versus 15.8±8.6 mm, P=0.0001). Despite the higher-risk patients and lesion profiles in the DES group, the incidence of major cardiac events at a 6-month clinical follow-up was lower in the DES than in the BMS group (20.0% versus 35.9%, respectively; P=0.039). Moreover, cardiac deaths occurred in 3 DES patients (3.5%), as compared with 6 (9.3%) in the BMS group (P=0.17). Conclusions—In this early experience with DES in unprotected left main, this procedure appears safe with favorable and improved clinical results as compared with historical control subjects with a BMS. A randomized study comparing surgery appears justified at present.

Renal insufficiency following contrast media administration trial (REMEDIAL) : A randomized comparison of 3 preventive strategies

Background— Volume supplementation by saline infusion combined with N-acetylcysteine (NAC) represents an effective strategy to prevent contrast agent–induced nephrotoxicity (CIN). Preliminary data support the concept that sodium bicarbonate and ascorbic acid also may be effective in preventing CIN. Methods and Results— Three hundred twenty-six consecutive patients with chronic kidney disease, referred to our institutions for coronary and/or peripheral procedures, were randomly assigned to prophylactic administration of 0.9% saline infusion plus NAC (n=111), sodium bicarbonate infusion plus NAC (n=108), and 0.9% saline plus ascorbic acid plus NAC (n=107). All enrolled patients had serum creatinine ≥2.0 mg/dL and/or estimated glomerular filtration rate <40 mL · min−1 · 1.73 m−2. Contrast nephropathy risk score was calculated in each patient. In all cases, iodixanol (an iso-osmolar, nonionic contrast agent) was administered. The primary end point was an increase of ≥25% in the creatinine concentration 48 hours after the procedure (CIN). The amount of contrast media administered (179±102, 169±92, and 169±94 mL, respectively; P=0.69) and risk scores (9.1±3.4, 9.5±3.6, and 9.3±3.6; P=0.21) were similar in the 3 groups. CIN occurred in 11 of 111 patients (9.9%) in the saline plus NAC group, in 2 of 108 (1.9%) in the bicarbonate plus NAC group (P=0.019 by Fisher exact test versus saline plus NAC group), and in 11 of 107 (10.3%) in the saline plus ascorbic acid plus NAC group (P=1.00 versus saline plus NAC group). Conclusions— The strategy of volume supplementation by sodium bicarbonate plus NAC seems to be superior to the combination of normal saline with NAC alone or with the addition of ascorbic acid in preventing CIN in patients at medium to high risk.

Percutaneous Treatment With Drug-Eluting Stent Implantation Versus Bypass Surgery for Unprotected Left Main Stenosis A Single-Center Experience

Background— Improvements in results with percutaneous coronary intervention (PCI) with drug-eluting stents (DES) may extend their use in patients with left main coronary artery (LMCA) stenosis. Methods and Results— Two hundred forty-nine patients with LMCA stenosis were treated with PCI and DES implantation (n=107) or coronary artery bypass grafting (CABG) (n=142), in a single center, between March 2002 and July 2004. A propensity analysis was performed to adjust for baseline differences between the two cohorts. At 1 year, there was no statistical difference in the occurrence of death in PCI versus CABG both for the unadjusted (OR=0.291; 95% CI=0.054 to 1.085; P=0.0710) and adjusted analyses (OR=0.331; 95% CI=0.055 to 1.404; P=0.1673). PCI was correlated to a lower occurrence of the composite end points of death and myocardial infarction (unadjusted OR=0.235; 95% CI=0.048 to 0.580; P=0.0002; adjusted OR=0.260; 95% CI=0.078 to 0.597; P=0.0005) and death, myocardial infarction, and cerebrovascular events (unadjusted OR=0.300; 95% CI=0.102 to 0.617; P=0.0004; adjusted OR=0.385; 95% CI=0.180 to 0.819; P=0.01). No difference was detected in the occurrence of major adverse cardiac and cerebrovascular event at the unadjusted (OR=0.675; 95% CI=0.371 to 1.189; P=0.1891) and adjusted analyses (OR=0.568; 95% CI=0.229 to 1.344; P=0.2266). Conclusions— At 1 year, in this single-center, retrospective experience, there was no difference in the degree of protection against death, stroke, myocardial infarction, and revascularization between PCI with DES and CABG for LMCA disease.

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.

Novel Approaches for Preventing or Limiting Events (Naples) II Trial Impact of a Single High Loading Dose of Atorvastatin on Periprocedural Myocardial Infarction

OBJECTIVES Atorvastatin administered at least 7 days before the percutaneous coronary intervention (PCI) reduces the rate of periprocedural myocardial infarction (MI). It is unknown whether a single, high (80 mg) loading dose of atorvastatin may reduce the rate of periprocedural MI. BACKGROUND Periprocedural MI is a prognostically important complication of PCI. METHODS The day before the elective PCI, 668 statin-naive patients were randomly assigned to atorvastatin 80 mg (atorvastatin group; n = 338) or no statin treatment (control group; n = 330). Creatine kinase-myocardial isoenzyme (CK-MB) (upper limit of normal [ULN] 3.5 ng/ml) and cardiac troponin I (ULN 0.10 ng/ml) were assessed before and 6 and 12 h after the intervention. Periprocedural MI was defined as a CK-MB elevation >3x ULN alone or associated with chest pain or ST-segment or T-wave abnormalities. RESULTS The incidence of a periprocedural MI was 9.5% in the atorvastatin group and 15.8% in the control group (odds ratio: 0.56; 95% confidence interval: 0.35 to 0.89; p = 0.014). Median CK-MB peak after PCI was 2.10 ng/ml (interquartile range 1.00 to 12.50 ng/ml) in the atorvastatin group and 3.20 ng/ml (interquartile range 1.37 to 16.07 ng/ml) in the control group (p = 0.014). The incidence of cardiac troponin I elevation >3x ULN was 26.6% in the atorvastatin group and 39.1% in the control group (odds ratio: 0.56; 95% confidence interval: 0.40 to 0.78; p < 0.001). CONCLUSIONS A single, high (80 mg) loading (within 24 h) dose of atorvastatin reduces the incidence of periprocedural MI in elective PCI.

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.

Favorable Long-Term Outcome After Drug-Eluting Stent Implantation in Nonbifurcation Lesions That Involve Unprotected Left Main Coronary Artery A Multicenter Registry

Background— The presence of a lumen narrowing at the ostium and the body of an unprotected left main coronary artery but does not require bifurcation treatment is a class I indication of surgical revascularization. Methods and Results— A total of 147 consecutive patients who had a stenosis in the ostium and/or the midshaft of an unprotected left main coronary artery (treatment of the bifurcation not required) and were electively treated with percutaneous coronary intervention and sirolimus-eluting stents (n=107) or paclitaxel-eluting stents (n=40) in 5 centres were included in this registry. In 72 patients (almost 50%), intravascular ultrasound guidance was performed. Procedural success was achieved in 99% of the patients; in 1 patient with stenosis in the left main coronary artery ostium, a >30% residual stenosis persisted at the end of the procedure, and the patient was referred for coronary artery bypass graft surgery. During hospitalization, no patients experienced a Q-wave myocardial infarction or died. One patient died 19 days after the procedure because of pulmonary infection. At long-term clinical follow-up (886±308 days), 5 patients had died; 7 patients had target vessel revascularization (5 repeat percutaneous coronary interventions and 2 coronary artery bypass graft surgeries), and of these only 1 patient had a target lesion revascularization. Angiographic follow-up was performed in 106 patients (72%) with a late loss of −0.01 mm. Restenosis in the left main trunk occurred only in 1 patient (0.9%). Conclusions— Percutaneous coronary intervention with sirolimus-eluting stents or paclitaxel-eluting stents implantation in nonbifurcation left main coronary artery lesions appears safe with a long-term major adverse clinical event rate of 7.4% and a restenosis rate of 0.9%.

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.

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.