Prognostic significance of post-clopidogrel platelet reactivity assessed by a point-of-care assay on thrombotic events after drug-eluting stent implantation.

AIMS: The aim of this study was to determine whether platelet reactivity on clopidogrel therapy, as measured by a point-of-care platelet function assay, is associated with thrombotic events after percutaneous coronary intervention (PCI) with drug-eluting stents (DESs). METHODS AND RESULTS: Platelet reactivity on clopidogrel (post-treatment reactivity) was measured with the VerifyNow P2Y12 assay (Accumetrics Inc., San Diego, CA, USA) in 380 patients undergoing PCI with sirolimus-eluting stents. Receiver-operating characteristic curve analysis was used to derive the optimal cut-off value for post-treatment reactivity in predicting 6 month out-of-hospital cardiovascular (CV) death, non-fatal MI, or stent thrombosis. The mean post-treatment reactivity was 184 +/- 85 PRU (P2Y12 reaction units). The optimal cut-off for the combined endpoint was a post-treatment reactivity > or =235 PRU [area under the curve 0.711 (95% confidence interval 0.529-0.893), P = 0.03], which was similar to the threshold of the upper tertile (231 PRU). Patients with post-treatment reactivity greater than the cut-off value had significantly higher rates of CV death (2.8 vs. 0%, P = 0.04), stent thrombosis (4.6 vs. 0%, P = 0.004), and the combined endpoint (6.5 vs. 1.0%, P = 0.008). CONCLUSION: High post-treatment platelet reactivity measured with a point-of-care platelet function assay is associated with post-discharge events after PCI with DES, including stent thrombosis. Investigation of alternative clopidogrel dosing regimens to reduce ischaemic events in high-risk patients identified by this assay is warranted.

Efficacy and safety of triple antiplatelet therapy with and without concomitant anticoagulation during elective percutaneous coronary intervention (the REMOVE trial).

Adjunctive glycoprotein IIb/IIIa inhibition decreases ischemic events after percutaneous coronary intervention (PCI) but is associated with increased bleeding. We hypothesized that maximal antiplatelet therapy with aspirin, a thienopyridine, and a glycoprotein IIb/IIIa inhibitor without unfractionated heparin (UFH) would result in fewer bleeding complications and maintain efficacy in elective PCI. A total of 159 patients undergoing elective PCI were randomized to intraprocedural eptifibatide alone or eptifibatide plus UFH. Patients received aspirin 325 mg and clopidogrel 300 mg before the procedure. The primary end point was the Landefeld bleeding index. Secondary end points included the composite clinical outcome of in-hospital death, myocardial infarction, urgent target vessel revascularization, and Thrombolysis In Myocardial Infarction major bleeding, and a composite bleeding outcome of major, minor, and nuisance bleeding. The Landefeld bleeding index was significantly lower in the eptifibatide-only group compared with the eptifibatide-plus-UFH group (3.0 vs 3.9, p = 0.03). There was no significant difference in the composite clinical end point between groups (eptifibatide only 17% vs eptifibatide plus UFH 15%, p = 0.7). There was a trend toward a decrease in the composite bleeding end point in the eptifibatide-only compared with the eptifibatide-plus-UFH group (43% vs 56%, p = 0.10). In conclusion, during elective PCI, a strategy of aggressive antiplatelet therapy using aspirin, clopidogrel, and eptifibatide without anticoagulant therapy appears to decrease bleeding complications.

Early- and medium-term outcomes after paclitaxel-eluting stent implantation for sirolimus-eluting stent failure.

The optimal treatment for sirolimus-eluting stent (SES) restenosis is not known. This study evaluated the safety and clinical outcome of paclitaxel-eluting stent (PES) implantation for SES restenosis. From March 2004 to July 2005, PESs were implanted in 125 patients with 140 lesions with SES restenosis. Acute and 6-month clinical outcomes were determined through review of the medical record and/or telephone interview. In-hospital major adverse cardiac events (death, nonfatal myocardial infarction, or repeat revascularization) occurred in 14 patients (11.2%), driven entirely by postprocedure non-Q-wave myocardial infarction. At a mean clinical follow-up of 7.2 +/- 1.8 months, the incidence of target lesion revascularization (TLR) was 14.0%, and the rate of major adverse cardiac events was 17.2%. Subacute thrombosis occurred in 2 patients (1.6%). Length of PES implanted, postprocedure diameter stenosis, and total occlusion of the target lesion were independent predictors of TLR. In patients with de novo SES restenosis, TLR was only 8.7%. In conclusion, at medium-term follow-up, PES implantation for SES failure appears to be safe and effective, although efficacy is decreased in the setting of total occlusions, greater residual diameter stenosis, and longer PESs.

Direct thrombin inhibition appears to be a safe and effective anticoagulant for percutaneous bypass graft interventions.

BACKGROUND: Percutaneous coronary interventions (PCI) of coronary artery bypass grafts (CABG) are associated with worse outcomes compared with those of native coronary PCI. Little is known concerning the use of direct thrombin inhibition during CABG intervention. The objective of this report is to examine the safety and efficacy of bivalirudin with GPIIb/IIIa blockade inhibition in patients undergoing CABG PCI. GP IIb/IIIa use was provisional in REPLACE-2 and planned in REPLACE-1. METHODS AND RESULTS: A post hoc analysis of patients undergoing CABG PCI in the REPLACE-1 and -2 trials was performed. In REPLACE-1, patients were randomized to either heparin or bivalirudin, with GP IIb/IIIa inhibitor use at the operator's discretion. In REPLACE-2, patients were randomized to heparin plus GP IIb/IIIa inhibition versus bivalirudin with provisional GP IIb/IIIa blockade. In both studies, randomized treatment groups were well matched. In unadjusted and logistic regression analysis, there were no significant differences in the combined endpoint of death, myocardial infarction, urgent revascularization, or major bleeding when patients were treated with either heparin or bivalirudin. Individual safety and efficacy endpoints were also similar. Minor bleeding was significantly reduced in patients treated with bivalirudin (14.8% vs. 22.7%, P = 0.037). Follow-up data available from the REPLACE-2 trial at 12 months found similar efficacy between groups with a trend towards decreased 12 month mortality in the bivalirudin vs. heparin groups (4.2% vs. 7.8%, P = 0.16). CONCLUSION: CABG PCI using bivalirudin with provisional GPIIb/IIIa inhibition appears to provide similar safety and efficacy to heparin with GPIIb/IIIa inhibition.

Recent trends in the percutaneous treatment of chronic total coronary occlusions.

Percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) has a lower success rate than PCI for non-CTO lesions. We sought to determine trends in the treatment of CTOs within the current interventional era. Using 4 sequential recruitment waves of the National Heart, Lung, and Blood Institute Dynamic Registry, we assessed the relative prevalence and success rates in treating CTO (n=371) versus non-CTO (n=4,802) lesions over a 7-year period (1997 to 2004). Characteristics of attempted lesions and factors associated with PCI outcome were evaluated. CTO lesion attempts decreased by 41% over time, from 9.6% (1997 to 1998) to 5.7% (2004, p<0.0001 for trend). More contemporary CTO lesions were longer (22.4 vs 17.0 mm, p=0.006 for trend), had thrombus less often (21.3% vs 35.4%, p=0.03 for trend), and were more often treated with stents (69.8% vs 45.4% p=0.02). The rate of successful intervention for CTO lesions decreased nonsignificantly during this time, from 79.7% to 71.4% (p=0.18). Using multivariable analysis, female gender (adjusted odds ratio 0.42, 95% confidence interval 0.20 to 0.88, p=0.02), and thrombus (adjusted odds ratio 0.31, 95% confidence interval 0.15 to 0.61, p=0.0008) were associated with higher success rates, whereas the presence of severe noncardiac disease (adjusted odds ratio 1.91, 95% confidence interval 1.05 to 3.45, p=0.03) was associated with a higher risk for PCI failure. Recruitment wave and patient age were not independently related to lesion success. In conclusion, during the PCI period of 1997 to 2004, CTO lesions were attempted less frequently and success rates did not increase, indicating a need for new operator techniques or device technologies to treat this important lesion subset by a percutaneous approach.

Differential effects between intravenous and targeted renal delivery of fenoldopam on renal function and blood pressure in patients undergoing cardiac catheterization.

A randomized, controlled clinical trial demonstrated that intravenous (IV) fenoldopam did not prevent further deterioration in renal function after contrast administration in patients with chronic renal insufficiency. This lack of effect may have been a consequence of the inability to administer an effective renal dose of IV fenoldopam. This study sought to determine whether compared with IV administration, selective intrarenal (IR) fenoldopam would increase local concentration, leading to a higher glomerular filtration rate (GFR), and, because of first-pass renal elimination, result in lower systemic drug levels and less decrease in systemic blood pressure (BP). A randomized, controlled, open-label, partial crossover design trial was conducted in which 33 patients who underwent coronary angiography were randomized in a 1:2 ratio to control or fenoldopam (initially IV, then crossed over to IR through a bifurcated renal infusion catheter). Compared with IV fenoldopam, IR administration was associated with a significantly higher GFR (73.7 +/- 3.1 vs 62.6 +/- 2.5 ml/min, p = 0.0007) and renal plasma flow (537.2 +/- 34.0 vs 494.0 +/- 35.5 ml/min, p <0.01), lower fenoldopam plasma levels (3.3 +/- 0.3 vs 4.8 +/- 0.3 ng/ml, p <0.0001), and greater nadir systolic BP (125.5 +/- 3.6 vs 117.4 +/- 2.8 mm Hg, p <0.0001). Two hours after drug discontinuation after contrast administration, GFRs in the patients who received IR fenoldopam remained higher than in controls (+15.0 ml/min [+25%] vs -8.0 ml/min [-14.0%], p <0.05). In conclusion, this pilot trial demonstrates that the IR infusion of fenoldopam is safe and practical, producing greater renal effect and less reduction of BP than IV infusion. It would be appropriate to restudy this renal vasodilator for the prevention of contrast nephropathy, using selective IR delivery.

Serial angiographic follow-up of sirolimus-eluting stents for unprotected left main coronary artery revascularization.

OBJECTIVES: This study was performed to evaluate the clinical and serial angiographic outcomes of patients undergoing sirolimus-eluting stent (SES) implantation for unprotected left main coronary artery (LMCA) stenosis. BACKGROUND: The efficacy of SES has led to their expanded use for off-label indications, including LMCA disease. METHODS: Unprotected LMCA intervention with SES was attempted in 50 patients. Surveillance angiography was performed at three and nine months' follow-up. RESULTS: The target lesion involved the distal LMCA in 47 patients (94%). In-lesion restenosis occurred in 21 patients (42%), was focal in 85% of cases, and in 82% involved the branch ostia, sparing the LMCA itself. Target lesion revascularization (TLR) occurred in 19 patients (38%) over a mean follow-up of 276 +/- 57 days; TLR was ischemia-driven in 7 patients (14%). Late loss was significantly greater within the left circumflex (LCX) ostium compared to the parent vessel (PV) of the LMCA bifurcation (0.83 +/- 0.89 mm vs. 0.49 +/- 0.72 mm, p = 0.04). Late loss continued to increase between three- and nine-month follow-up. Final minimal luminal diameter and maximal balloon pressure were independent predictors of restenosis of the PV. CONCLUSIONS: Restenosis is a frequent finding when serial angiographic follow-up is performed after SES implantation for unprotected distal LMCA lesions. Restenosis is usually focal, most often involves the LCX ostium, and often occurs without symptoms.

Clinical outcomes after sirolimus-eluting stent implantation for de novo saphenous vein graft lesions.

The purpose of this study was to evaluate the clinical outcome of patients undergoing sirolimus-eluting stent implantation for de novo lesions within saphenous vein grafts (SVGs). Although the incidence of restenosis following sirolimus-eluting stenting (SES) of native coronary arteries is low, the efficacy of SES to treat de novo lesions within SVGs has not been well studied. A total of 35 patients underwent SES implantation of 39 lesions during 36 procedures. All patients had a minimum follow-up of 6 months following the index procedure. The mean bypass graft age was 10.1 +/- 6.5 years (range, 0-23 years). In-hospital major adverse cardiac events [death, myocardial infarction, thrombosis, or target vessel revascularization (TVR)] occurred in four patients (11%). Clinical follow-up was obtained in 100% of patients (mean follow-up, 7.5 +/- 2.2 months). There was one cardiac death, presumed due to stent thrombosis. TVR occurred in only two patients (6%). Myocardial infarction (MI) occurred in four patients (11%), all attributable to a nontarget vessel. The combined endpoint of death, MI, or TVR occurred in seven patients (20%). Freedom from death, nonfatal MI, thrombosis, or any revascularization was 65%. Early experience indicates sirolimus-eluting stents for de novo saphenous vein graft lesions have a low (6%) rate of clinically driven target vessel revascularization. By 7-month follow-up, event-free survival is limited primarily by disease in nontarget vessels.

Treatment of left anterior descending coronary artery disease with sirolimus-eluting stents.

BACKGROUND: Revascularization strategies often hinge on the presence and degree of left anterior descending coronary artery (LAD) stenosis. A decision for bypass surgery is often based on the durability of surgical LAD revascularization compared with percutaneous approaches. By decreasing restenosis, drug-eluting stents may have reduced the "reintervention gap" between surgery and percutaneous intervention, making the percutaneous route preferable. METHODS AND RESULTS: Of the 1101 patients in the SIRIUS trial, 459 with an LAD stenosis were randomized to percutaneous intervention with either sirolimus-eluting or bare-metal stents. Baseline demographic, clinical, and angiographic data were obtained. Patients had 1-year clinical and 8-month angiographic follow-up. Baseline characteristics were similar in both groups. The majority of lesions were tubular type B lesions (69.7%) with a mean diameter of 2.73 mm and a mean length of 14.0 mm. The binary in-stent restenosis rate was 2% for the sirolimus stent group and 41.6% for the bare-metal arm (relative risk, 0.05; 95% CI, 0.02 to 0.1; P<0.001). One-year major adverse events (defined as cardiac death, Q-wave and non-Q-wave myocardial infarction, or target vessel revascularization) was decreased 59% in the sirolimus-stent group (9.8% versus 24.9%; relative risk, 0.39; 95% CI, 0.26 to 0.61; P<0.001). Subgroup analysis of 135 patients with proximal LAD lesions showed similar benefits. In-stent restenosis was 0 in the proximal LAD sirolimus-eluting group (n=67), compared with 38% in the bare-metal arm (n=68), and major adverse events demonstrated a similar trend, with a 50% decrease compared with control patients (10.4% versus 20.6%, P=NS). CONCLUSIONS: Sirolimus-eluting stents significantly decrease revascularization rates in LAD lesions. At 1 year, sirolimus-eluting stent revascularization rates are comparable to historic single vessel bypass surgery revascularization rates.

Calcific aortic stenosis in the elderly: a brief overview.

Aortic stenosis is the most common valvular lesion in patients above the age of 65. The etiology, presentation, and management of aortic stenosis differs in the elderly compared to younger patients in many ways. Many of the classic physical findings are absent in the elderly, making the diagnosis of critical aortic stenosis more difficult. Due to coexisting morbidity in many elderly patients, there is often a reluctance to recommend aortic valve replacement despite the dismal prognosis of medical therapy. In the following review, the authors discuss the pathophysiology, presentation, and management of aortic stenosis in the elderly.