Carlo Briguori

Stent thrombosis with drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis

BACKGROUND The relative safety of drug-eluting stents and bare-metal stents, especially with respect to stent thrombosis, continues to be debated. In view of the overall low frequency of stent thrombosis, large sample sizes are needed to accurately estimate treatment differences between stents. We compared the risk of thrombosis between bare-metal and drug-eluting stents. METHODS For this network meta-analysis, randomised controlled trials comparing different drug-eluting stents or drug-eluting with bare-metal stents currently approved in the USA were identified through Medline, Embase, Cochrane databases, and proceedings of international meetings. Information about study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes was extracted. FINDINGS 49 trials including 50,844 patients randomly assigned to treatment groups were analysed. 1-year definite stent thrombosis was significantly lower with cobalt-chromium everolimus eluting stents (CoCr-EES) than with bare-metal stents (odds ratio [OR] 0·23, 95% CI 0·13-0·41). The significant difference in stent thrombosis between CoCr-EES and bare-metal stents was evident as early as 30 days (OR 0·21, 95% CI 0·11-0·42) and was also significant between 31 days and 1 year (OR 0·27, 95% CI 0·08-0·74). CoCr-EES were also associated with significantly lower rates of 1-year definite stent thrombosis compared with paclitaxel-eluting stents (OR 0·28, 95% CI 0·16-0·48), permanent polymer-based sirolimus-eluting stents (OR 0·41, 95% CI 0·24-0·70), phosphorylcholine-based zotarolimus-eluting stents (OR 0·21, 95% CI 0·10-0·44), and Resolute zotarolimus-eluting stents (OR 0·14, 95% CI 0·03-0·47). At 2-year follow-up, CoCr-EES were still associated with significantly lower rates of definite stent thrombosis than were bare-metal (OR 0·35, 95% CI 0·17-0·69) and paclitaxel-eluting stents (OR 0·34, 95% CI 0·19-0·62). No other drug-eluting stent had lower definite thrombosis rates compared with bare-metal stents at 2-year follow-up. INTERPRETATION In randomised studies completed to date, CoCr-EES has the lowest rate of stent thrombosis within 2 years of implantation. The finding that CoCr-EES also reduced stent thrombosis compared with bare-metal stents, if confirmed in future randomised trials, represents a paradigm shift. FUNDING The Cardiovascular Research Foundation.

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.

Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial

BACKGROUND It is unclear whether radial compared with femoral access improves outcomes in unselected patients with acute coronary syndromes undergoing invasive management. METHODS We did a randomised, multicentre, superiority trial comparing transradial against transfemoral access in patients with acute coronary syndrome with or without ST-segment elevation myocardial infarction who were about to undergo coronary angiography and percutaneous coronary intervention. Patients were randomly allocated (1:1) to radial or femoral access with a web-based system. The randomisation sequence was computer generated, blocked, and stratified by use of ticagrelor or prasugrel, type of acute coronary syndrome (ST-segment elevation myocardial infarction, troponin positive or negative, non-ST-segment elevation acute coronary syndrome), and anticipated use of immediate percutaneous coronary intervention. Outcome assessors were masked to treatment allocation. The 30-day coprimary outcomes were major adverse cardiovascular events, defined as death, myocardial infarction, or stroke, and net adverse clinical events, defined as major adverse cardiovascular events or Bleeding Academic Research Consortium (BARC) major bleeding unrelated to coronary artery bypass graft surgery. The analysis was by intention to treat. The two-sided α was prespecified at 0·025. The trial is registered at ClinicalTrials.gov, number NCT01433627. FINDINGS We randomly assigned 8404 patients with acute coronary syndrome, with or without ST-segment elevation, to radial (4197) or femoral (4207) access for coronary angiography and percutaneous coronary intervention. 369 (8·8%) patients with radial access had major adverse cardiovascular events, compared with 429 (10·3%) patients with femoral access (rate ratio [RR] 0·85, 95% CI 0·74-0·99; p=0·0307), non-significant at α of 0·025. 410 (9·8%) patients with radial access had net adverse clinical events compared with 486 (11·7%) patients with femoral access (0·83, 95% CI 0·73-0·96; p=0·0092). The difference was driven by BARC major bleeding unrelated to coronary artery bypass graft surgery (1·6% vs 2·3%, RR 0·67, 95% CI 0·49-0·92; p=0·013) and all-cause mortality (1·6% vs 2·2%, RR 0·72, 95% CI 0·53-0·99; p=0·045). INTERPRETATION In patients with acute coronary syndrome undergoing invasive management, radial as compared with femoral access reduces net adverse clinical events, through a reduction in major bleeding and all-cause mortality. FUNDING The Medicines Company and Terumo.

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.

Acetylcysteine and contrast agent-associated nephrotoxicity

OBJECTIVES Prophylactic acetylcysteine along with hydration seems to be better than hydration alone in preventing the reduction in renal function induced by a contrast dye. BACKGROUND Contrast media can lead to acute renal failure that may occasionally require hemodialysis. METHODS One hundred eighty-three consecutive patients with impairment of renal function, undergoing coronary and/or peripheral angiography and/or angioplasty, were randomly assigned to receive 0.45% saline intravenously and acetylcysteine (600 mg orally twice daily; group A, n = 92) or 0.45% saline intravenously alone (group B, n = 91) before and after nonionic, low-osmolality contrast dye administration. RESULTS The baseline serum creatinine concentrations were similar (1.5 +/- 0.4 mg/dl in group A vs. 1.5 +/- 0.4 mg/dl in group B; p = 0.37). An increase of > or =25% in the baseline creatinine level 48 h after the procedure occurred in 6 (6.5%) of 92 patients in group A and in 10 (11%) of 91 patients in group B (p = 0.22). In the subgroup with a low (<140 ml) contrast dose, renal function deterioration occurred in 5 (8.5%) of 60 patients in group B and in 0 of 60 patients in group A (p = 0.02; odds ratio [OR] 0.44, 95% confidence interval [CI] 0.35 to 0.54). In the subgroup with a high contrast dose, no difference was found (5/31 vs. 6/32 patients, p = 0.78). By multivariate analysis, the amount of contrast agent, but not the treatment strategy, was a predictor of the occurrence of contrast dye-associated nephrotoxicity (OR 2.58, 95% CI 1.1 to 4.9; p = 0.035). CONCLUSIONS In patients with reduced renal function undergoing angiography and/or angioplasty, the amount of contrast agent, but not the administration of prophylactic acetylcysteine, was a predictor of renal function deterioration. Prophylactic acetylcysteine might provide better protection than hydration alone, only when a small volume of contrast agent is used.

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.

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.

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.