Flavio Airoldi

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.

Randomized Study of the Crush Technique Versus Provisional Side-Branch Stenting in True Coronary Bifurcations The CACTUS (Coronary Bifurcations: Application of the Crushing Technique Using Sirolimus-Eluting Stents) Study

Background— Sirolimus-eluting stents have been reported to be effective in the treatment of coronary bifurcations. Still, it has not been fully clarified which strategy would provide the best results with true bifurcation lesions. Methods and Results— The CACTUS trial (Coronary bifurcations: Application of the Crushing Technique Using Sirolimus-eluting stents) is a prospective, randomized, multicenter study comparing 2 different techniques of stenting, with mandatory final kissing-balloon inflation, in true bifurcations: (1) elective “crush” stenting and (2) stenting of only the main branch, with provisional side-branch T-stenting. From August 2004 to June 2007, 350 patients were enrolled in 12 European centers. The primary angiographic end point was the in-segment restenosis rate, and the primary clinical end point was the occurrence of major adverse cardiac events (cardiac death, myocardial infarction, or target-vessel revascularization) at 6 months. At 6 months, angiographic restenosis rates were not different between the crush group (4.6% and 13.2% in the main branch and side branch, respectively) and the provisional stenting group (6.7% and 14.7% in the main branch and side branch, respectively; P=NS). Additional stenting on the side branch in the provisional stenting group was required in 31% of lesions. Rates of major adverse cardiac events were also similar in the 2 groups (15.8% in the crush group versus 15% in the provisional stenting group, P=NS). Conclusions— In most bifurcations with a significant stenosis in both branches, a provisional strategy of stenting the main branch only is effective, with the need to implant a second stent on the side branch occurring in approximately one third of cases. The implantation of 2 stents does not appear to be associated with a higher incidence of adverse events at 6 months.

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.

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%.

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.

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.