Successful Drug-eluting Stent Implantation Research Articles

Prediction of Left Ventricular Function After Drug-Eluting Stent Implantation for Chronic Total Coronary Occlusions

We studied the effect of drug-eluting stent implantation for chronic total coronary occlusion (CTO) on left ventricular volumes and function and assessed the predictive value of magnetic resonance imaging (MRI) performed before revascularization. The effect of recanalization of CTO on long-term left ventricular function and the value of myocardial viability assessment with MRI is incompletely understood. Twenty-seven patients underwent contrast-enhanced MRI before and five months after successful drug-eluting stent implantation for CTO. A CTO was defined as a complete occlusion of a major epicardial coronary artery existing for at least six weeks (mean, 7 +/- 5 months). Myocardial wall thickening and left ventricular volumes were quantified on cine-images, and the transmural extent of infarction (TEI) was scored on delayed-enhancement images. A significant decrease in mean end-systolic volume index (34 +/- 13 ml/m2 to 31 +/- 13 ml/m2; p = 0.02) and mean end-diastolic volume index (84 +/- 15 ml/m2 to 79 +/- 15 ml/m2; p < 0.002) was observed, whereas the mean ejection fraction did not change significantly (61 +/- 9% to 62 +/- 11%; p = 0.54). The extent of the left ventricle that was dysfunctional but viable before revascularization was related to improvement in end-systolic volume index (R = 0.46; p = 0.01) and ejection fraction (R = 0.49; p = 0.01) but not to the end-diastolic volume index (R = 0.10; p = 0.53). Segmental wall thickening improved significantly in segments with <25% TEI (21 +/- 15% to 35 +/- 25%; p < 0.001), tended to improve in segments with 25% to 75% TEI (18 +/- 22% to 27 +/- 22%; p = 0.10), whereas segments with >75% TEI did not improve (4 +/- 14% to -9 +/- 14%; p = 0.54). Drug-eluting stent implantation for a CTO has a beneficial effect on left ventricular volumes and function that can be predicted by performing MRI before revascularization.

Incidence, Predictors, and Outcome of Thrombosis After Successful Implantation of Drug-Eluting Stents

Traditionally, stent thrombosis has been regarded as a complication of percutaneous coronary interventions during the first 30 postprocedural days. However, delayed endothelialization associated with the implantation of drug-eluting stents may extend the risk of thrombosis beyond 30 days. Data are limited regarding the risks and the impact of this phenomenon outside clinical trials. To evaluate the incidence, predictors, and clinical outcome of stent thrombosis after implantation of sirolimus-eluting and paclitaxel-eluting stents in routine clinical practice. Prospective observational cohort study conducted at 1 academic hospital and 2 community hospitals in Germany and Italy. A total of 2229 consecutive patients underwent successful implantation of sirolimus-eluting (1062 patients, 1996 lesions, 2272 stents) or paclitaxel-eluting (1167 patients, 1801 lesions, 2223 stents) stents between April 2002 and January 2004. Implantation of a drug-eluting stent (sirolimus or paclitaxel). All patients were pretreated with ticlopidine or clopidogrel and aspirin. Aspirin was continued indefinitely and clopidogrel or ticlopidine for at least 3 months after sirolimus-eluting and for at least 6 months after paclitaxel-eluting stent implantation. Subacute thrombosis (from procedure end through 30 days), late thrombosis (>30 days), and cumulative stent thrombosis. At 9-month follow-up, 29 patients (1.3%) had stent thrombosis (9 [0.8%] with sirolimus and 20 [1.7%] with paclitaxel; P = .09). Fourteen patients had subacute thrombosis (0.6%) and 15 patients had late thrombosis (0.7%). Among these 29 patients, 13 died (case fatality rate, 45%). Independent predictors of stent thrombosis were premature antiplatelet therapy discontinuation (hazard ratio [HR], 89.78; 95% CI, 29.90-269.60; P<.001), renal failure (HR, 6.49; 95% CI, 2.60-16.15; P<.001), bifurcation lesions (HR, 6.42; 95% CI, 2.93-14.07; P<.001), diabetes (HR, 3.71; 95% CI, 1.74-7.89; P = .001), and a lower ejection fraction (HR, 1.09; 95% CI, 1.05-1.36; P<.001 for each 10% decrease). The cumulative incidence of stent thrombosis 9 months after successful drug-eluting stent implantation in consecutive "real-world" patients was substantially higher than the rate reported in clinical trials. Premature antiplatelet therapy discontinuation, renal failure, bifurcation lesions, diabetes, and low ejection fraction were identified as predictors of thrombotic events.

Stent Thrombosis after Successful Drug-Eluting Stent Implantation

Background and Objectives:Stent thrombosis (ST) after a successful drug-eluting stent (DES) implantation has been reported in around 1% of clinical trials. However, the incidence of ST with a DES in practice is not well known. Here, we evaluated the possible causes of ST encountered in four Korean hospitals. Subjects and Methods:Between March 2003 and December 2003, 450 patients were treated using a DES in the four study hospitals. We reviewed the clinical and procedural characteristics of 8 patients that experienced ST after a successful DES implantation. Results:Eight patients (1.8%), who were administered antiplatelet medication, experienced ST, with a mortality of 50% at the 2 month follow-up. ST occurred within 7 days in all patients, with the exception of one, with an occurrence 37 days after intervention. Initially, all patients were diagnosed as having acute coronary syndrome. Direct PTCA was performed in 3 patients (38%). Severe calcification or a thrombus was noted in 6 (67%) of 9 lesions. In all cases, no GPIIbIIIa inhibitors were used prior to the DES implantation. Incomplete lesion coverage and incomplete stent expansion appeared in 7 (88%) cases. Conclusion:Our study demonstrated that full expansion of the DES and complete lesion coverage must be accomplished, with high pressure inflation or use of cutting balloon preferably under IVUS guidance, for the prevention of ST. Those patients with acute coronary syndrome might warrant intensive antiplatelet therapy, including GPIIbIIIa inhibitors. (Korean Circulation J 2005;35:163-171)