Evaluation Of Drug Eluting Stents And Ischemic Events Research Articles

Machine Learning to Predict Stent Restenosis Based on Daily Demographic, Clinical, and Angiographic Characteristics

BackgroundMachine learning (ML) has arrived in medicine to deliver individually adapted medical care. This study sought to use ML to discriminate stent restenosis (SR) compared with existing predictive scores of SR. To develop an easily applicable model, we performed our predictions without any additional variables other than those obtained in daily practice. MethodsThe dataset, obtained from the Grupo de Análisis de la Cardiopatía Isquémica Aguda (GRACIA)-3 trial, consisted of 263 patients with demographic, clinical, and angiographic characteristics; 23 (9%) of them presented with SR at 12 months after stent implantation. A methodology to work with small imbalanced datasets, based in cross-validation and the precision/recall (PR) plots, was used, and state-of-the-art ML classifiers were trained. ResultsOur best performing model (0.46, area under the PR curve [AUC-PR]) was developed with an extremely randomized trees classifier, which showed better performance than chance alone (0.09 AUC-PR, corresponding to the 9% of patients presenting SR in our dataset) and 3 existing scores; Prevention of Restenosis With Tranilast and its Outcomes (PRESTO)-1 (0.31 AUC-PR), PRESTO-2 (0.27 AUC-PR), and Evaluation of Drug-Eluting Stents and Ischemic Events (EVENT) (0.18 AUC-PR). The most important variables ranked according to their contribution to the predictions were diabetes, ≥2 vessel-coronary disease, post-percutaneous coronary intervention thrombolysis in myocardial infarction (PCI TIMI)-flow, abnormal platelets, post-PCI thrombus, and abnormal cholesterol. To counteract the lack of external validation for our study, we deployed our ML algorithm in an open source calculator, in which the model would stratify patients of high and low risk as an example tool to determine generalizability of prediction models from small imbalanced sample size. ConclusionsApplied immediately after stent implantation, a ML model better differentiates those patients who will present with SR over current discriminators.

Prognostic implications of procedural vs spontaneous myocardial infarction: Results from the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) registry

In randomized clinical trials, procedural myocardial infarction (MI) or spontaneous MI is often weighted equally as a component of a composite clinical end point. An underlying assumption of this approach is that procedural and spontaneous MIs have similar prognostic impact. Our aim was to evaluate the prognostic impact of procedural vs spontaneous MI in patients undergoing percutaneous coronary intervention (PCI). We used data from the EVENT registry to examine the relative prognostic impact of procedural vs spontaneous MI. For the purposes of this study, patients undergoing initial PCI were stratified into 3 groups-no MI, procedural MI, or spontaneous MI-based on standard definitions applied at the time of the index procedure and followed for 1 year for outcomes of all-cause mortality and cardiovascular mortality. Multiple propensity score adjustment analysis was used to adjust for differences in baseline covariates among the 3 groups. Among 7,380 patients included in this analysis, 4,568 (62%) patients had no MI, 580 (8%) patients had procedural MI at the time of their index procedure, and 2,232 (30%) patients presented with a spontaneous MI before PCI. In unadjusted analyses, there was a graded increase in risk of 1-year mortality (1.9% vs 3.1% vs 3.9%; P < .0001) and cardiovascular death (0.5% vs 1.0% vs 1.7%; P < .0001) across the 3 groups. After adjusting for propensity scores, spontaneous MI (adjusted hazard ratio [HR] 1.62, 95% CI 1.11-2.37, P = .01) but not procedural MI (adjusted HR 1.51, 95% CI 0.89-2.54, P = .12) was independently associated with death at 12 months when compared with the no-MI group. Findings were similar when the analysis was limited to cardiovascular death (adjusted HRs 3.14 [95% CI 1.68-5.90, P < .001] and 1.74 [95% CI 0.69-4.40, P = .24], respectively). Among patients undergoing PCI, spontaneous but not procedural MI was independently associated with death and cardiovascular death at 1 year. These finding suggest that the prognostic impact of procedural MI may be less than that of spontaneous MI and should be considered in designing end points for future studies of coronary revascularization.

Troponin Criteria for Myocardial Infarction After Percutaneous Coronary Intervention

The universal definition of myocardial infarction specifies creatine kinase-MB fraction (CKMB) or troponin values more than 3 times the 99th percentile of the upper reference limit as diagnostic after percutaneous coronary intervention, with a preference for the use of troponin. Outcomes of 4930 patients with elective coronary stent placement between July 1, 2004, and September 30, 2007, as part of the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) registry were analyzed to test the association between 1-year mortality and postprocedure elevation of either CKMB or troponin. All values were normalized to the individual clinical center myocardial infarction diagnostic levels. Myocardial infarction occurred in 7.2% of patients by the CKMB criteria and in 24.3% of patients by the troponin criteria of greater than 3 times the diagnostic level. Both CKMB (hazard ratio [HR], 1.38; 95% CI, 1.22-1.55) and troponin (HR, 1.35; 95% CI, 1.18-1.54) as continuous values were associated with 1-year mortality. The mortality effect of a more than 3-fold increase was greater for CKMB (adjusted HR, 2.5; 95% CI, 1.5-4.1) than for troponin (adjusted HR, 1.7; 95% CI, 1.1-2.5). A troponin threshold more than 20 times the diagnostic level provided similar frequency (7.0%) and mortality risk (adjusted HR, 2.6; 95% CI, 1.6-4.3) as a 3-fold increase in CKMB. A regression spline model of the relationship between troponin and 1-year mortality demonstrated that the hazard of mortality increased from 1.02 at 3-fold to 1.67 at 20-fold troponin elevation. Troponin and CKMB elevations after percutaneous coronary intervention are associated with increased 1-year mortality rates, but thresholds for similar event frequency and mortality hazard are much higher for troponin than for CKMB.

Abstract 8888: Statin Therapy In Patients with Chronic Kidney Disease Undergoing Percutaneous Coronary Interventions Is Associated with Better One Year Outcomes. An Analysis from the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) Registry

Background: Primary and secondary prevention trials have shown that statin therapy reduces cardiovascular morbidity and mortality in patients with coronary artery disease. However, there has been a paucity of data concerning the benefits of statin use in patients with advanced chronic kidney disease (CKD) since they have been excluded from most trials. Methods and results: Of 10,148 patients entered into EVENT, a multicenter registry of unselected patients undergoing attempted PCI from July 2004- December 2007, we studied 2313 patients with advanced CKD (estimated glomerular filtration rate &lt; 60 mL/min based on the Modified Diet in Renal Disease calculation). Patients were stratified into those discharged on statins (n=1837, 79%) or not receiving statins at discharge (n=476, 21%). Patients discharged on statins were more often male and had higher prevalence of hypertension, recent myocardial infarction (MI) and greater use of beta blockers. One year mortality was 5.7% among statin users vs. 8.7% among non-users (HR 0.65; 95% CI: 0.45-0.93). When adjusted for covariates (age, gender, hypertension, recent MI (&lt; 7 days), ejection fraction, NYHA Class and medical therapy differences at discharge (warfarin, beta blockers, ACEi), one year all-cause mortality and composite end point of death/MI/repeat revascularization favored statin (HR 0.55 [0.34, 0.88] and 0.71 [0.51, 0.99] respectively). Conclusion: The proportion of patients with advanced CKD not discharged on statins post PCI is still high (21%). The current registry analysis showed favorable one year survival in patients discharged on statins following percutaneous coronary intervention in patients with advanced CKD, suggesting the need to investigate broader statin use in this clinical setting.

Abstract P271: Mortality Benefit With Drug-Eluting Stents in Observational Studies: Fact or Artifact? Insights From the Prospective, Multicenter EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) Registry

Background: Both randomized trials and observational studies comparing drug-eluting stents (DES) with bare metal stents (BMS) have demonstrated substantial reductions in target lesion revascularization (TLR) with DES use. Data on mortality, however, are strikingly disparate with only observational studies supporting a benefit of DES. We hypothesized that these differences are related predominantly to residual selection biases in non-randomized studies. Methods: We examined the association between stent type (DES vs. BMS) and both TLR and mortality over one year among 9266 unselected pts who underwent PCI at 55 US centers and were enrolled in the prospective EVENT registry from 2004 to 2007. In addition to standard approaches to risk-adjustment (i.e., multivariable regression and propensity matching), we performed an instrumental variable (IV) analysis using the treatment era (2007 vs. 2004-6) as the instrument. Results: Overall 88% pts received DES, and there was a substantial difference by treatment year (93% in 2004-06, 73% in 2007, p&lt;0.001). Unadjusted event rates over one year were significantly lower with DES compared to BMS (Death: 2.5% vs. 5.6%, TLR: 4.2% vs. 6.9%, p for both &lt;0.001). Both multivariable and propensity-matched Cox regression analyses demonstrated a significantly lower risk of death and TLR with DES use (Table). IV analysis showed a strong trend towards lower TLR with DES but no difference in mortality. Conclusion: Among unselected PCI patients in contemporary practice, DES use is associated with a consistent reduction in TLR regardless of risk-adjustment methodology but no effect on mortality using IV analysis. These findings underscore the limitations of conventional multivariable and propensity score analyses to adequately address both known and unknown factors influencing treatment selection in non-randomized studies. Adjusted * risk of post discharge clinical outcomes over one year after PCI with drug-eluting stents (reference: bare metal stents) Death Any TLR Hazard ratio (95% CI) P value Hazard ratio (95% CI) P value Multivariable Cox regression 0.51 (0.37-0.69) &lt;0.001 0.49 (0.37-0.64) &lt;0.001 Propensity-matched Cox regression 0.54 (0.39-0.74) &lt;0.001 0.52 (0.39-0.69) &lt;0.001 Absolute risk difference(%) (95% CI) P value Absolute risk difference (%) (95% CI) P value Instrumental variable analysis (instrument: treatment era) 1.9 (-1.9, 5.7) 0.33 -4.5 (-9.0, 0.3) 0.07 TLR: Target Lesion revascularization; * Adjusted/ matched for: Age, gender, insurance status, hyperlipidemia, hypertension, diabetes, smoking status, medical history (myocardial infarction, peripheral artery disease, stroke, heart failure), history of PCI or bypass surgery, e Glomerular filtration rate, ejection fraction, multivessel disease, attempted lesion location (left main, LAD, SVG), # lesions treated, stent length, # of stents, maximum stent diameter

Bleeding Risk Comparing Targeted Low-Dose Heparin With Bivalirudin in Patients Undergoing Percutaneous Coronary Intervention

Prior randomized trials have shown reduced bleeding with bivalirudin compared with unfractionated heparin (UFH) in patients undergoing percutaneous coronary intervention (PCI). However, it is not known if this benefit is also present when UFH doses are more tightly controlled (as measured by activated clotting time, ACT). Patients enrolled in the EVENT (Evaluation of Drug-Eluting Stents and Ischemic Events) registry, were divided into 3 groups, based on the antithrombotic drug used during PCI (UFH monotherapy, UFH+glycoprotein IIb-IIIa receptor inhibitor [GPI], or bivalirudin alone). Propensity score matching was used to adjust for measured covariates (89 variables) and to compare bivalirudin versus UFH monotherapy and bivalirudin versus UFH+GPI groups. The UFH groups were stratified based on ACT achieved (optimal ACT defined as 250-300 for UFH monotherapy and 200-250 when GPI was also used). The primary bleeding outcome was in-hospital composite bleeding, defined as events of access site bleeding, Thrombolysis In Myocardial Infarction major/minor bleeding, or transfusion. Primary (in-hospital death/myocardial infarction) and secondary ischemic outcomes (death/MI/unplanned repeat revascularization at 12 months) were also evaluated. Propensity score matching yielded 3022 patients for the UFH monotherapy versus bivalirudin comparison and 3520 patients for the UFH+GPI versus bivalirudin comparison. Bivalirudin use was associated with numerically lower bleeding rates at all categories of achieved ACT when compared with UFH (low, optimal, high ACT: 2.5% versus 4.7%, 1.9% versus 6.0%, 3.1% versus 4.8%, respectively) or heparin+GPI groups (low, optimal, high ACT: 0.0% versus 2.7%, 2.7% versus 5.2%, 2.4% versus 6.1%, respectively) and was not associated with any statistically significant increase in either primary or secondary ischemic outcomes. Among unselected patients undergoing PCI, bivalirudin use during PCI was associated with a lower risk of bleeding at all comparator ACT levels without an increase in ischemic outcomes.

Prognostic Implications of Creatine Kinase-MB Elevation After Percutaneous Coronary Intervention

Creatine kinase-MB (CK-MB) elevation after percutaneous coronary intervention (PCI) has been associated with increased risk for mortality. Although most studies have defined periprocedural myocardial infarction (pMI) as an elevation in CK-MB >3× upper limit of normal (ULN), use of different CK-MB assays and variation in site-specific definitions of the ULN may limit the value of such relative thresholds. We used data from the multicenter Evaluation of Drug-Eluting Stents and Ischemic Events (EVENT) registry to examine the impact of variations in site-specific thresholds for CK-MB elevation on the incidence of pMI as well as the relationship between absolute peak levels of CK-MB after PCI and 1-year mortality. The study cohort consisted of 6347 patients who underwent nonemergent PCI and had normal CK-MB at baseline. Across the 59 study centers, the ULN for CK-MB ranged from 2.6 to 10.4 ng/mL (median, 5.0 ng/mL), and there was an inverse relationship between the site-specific ULN and the incidence of pMI (defined as CK-MB elevation >3× ULN). Although any postprocedure elevation of CK-MB was associated with an adverse prognosis, in categorical analyses, only CK-MB ≥50 ng/mL was independently associated with increased 1-year mortality (hazard ratio, 4.71; 95% confidence interval, 2.42 to 9.13; P<0.001). Spline analysis using peak CK-MB as a continuous variable suggested a graded, nonlinear relationship with 1-year mortality, with an inflection point at ≈30 ng/mL. Among unselected patients undergoing PCI, there is a graded relationship between CK-MB elevation after PCI and 1-year mortality that is particularly strong for large CK-MB elevations (>30 to 50 ng/mL). Future studies that include pMI as a clinical end point should consider using a core laboratory to assess CK-MB (to ensure consistency) and raising the threshold for defining pMI above current levels (to enhance clinical relevance).

Clinical and Economic Outcomes of Liberal Versus Selective Drug-Eluting Stent Use

Background— Although the benefits of drug-eluting stents (DES) for reducing restenosis after percutaneous coronary intervention are well established, the impact of alternative rates of DES use on population-level outcomes is unknown. Methods and Results— We used data from the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) registry to examine the clinical impact and cost-effectiveness of varying DES use rates in routine care. Between 2004 and 2007, 10 144 patients undergoing percutaneous coronary intervention were enrolled in the EVENT registry at 55 US centers. Clinical outcomes and cardiovascular-specific costs were assessed prospectively over 1 year of follow-up. Use of DES decreased from 92 in 2004 to 2006 (liberal use era; n=7587) to 68 in 2007 (selective use era; n=2557; P &lt;0.001). One-year rates of death or myocardial infarction were similar in both eras. Over this time period, the incidence of target lesion revascularization increased from 4.1 to 5.1, an absolute increase of 1.0 (95 confidence interval, 0.1 to 1.9; P =0.03), whereas total cardiovascular costs per patient decreased by $401 (95 confidence interval, 131 to 671; P =0.004). The risk-adjusted incremental cost-effectiveness ratio for the liberal versus selective DES era was $16 000 per target lesion revascularization event avoided, $27 000 per repeat revascularization avoided, and $433 000 per quality-adjusted life-year gained. Conclusions— In this prospective registry, a temporal reduction in DES use was associated with a small increase in target lesion revascularization and a modest reduction in total cardiovascular costs. These findings suggest that although clinical outcomes are marginally better with unrestricted DES use, this approach represents a relatively inefficient use of healthcare resources relative to several common benchmarks for cost-effective care.

Circulation : Clinical Summaries

<i>Circulation</i> : Clinical Summaries

Incidence and clinical outcome of minor surgery in the year after drug-eluting stent implantation: Results from the Evaluation of Drug-Eluting Stents and Ischemic Events Registry

The aim of the study was to describe the incidence and consequences of minor surgery after drug-eluting stent (DES) implantation. The Evaluation of Drug-Eluting Stents and Ischemic Events (EVENT) Registry prospectively enrolled unselected patients undergoing percutaneous coronary intervention at 47 US centers between July 2004 and December 2007. We examined 8,323 patients who received a DES in EVENT to determine the frequencies of minor surgery and postoperative adverse events. Minor surgery (defined as procedures not requiring a major surgical incision) was performed in 164 (2.0%) of 8,323 patients <1 year after stenting, as follows: pacemaker/defibrillator implantation (46%), eye surgery (17%), orthopedic (9%), dermatologic (8%), endovascular (6%), and gastrointestinal procedures (5%). Compared with patients who did not undergo minor surgery, those who did were older, had more comorbidities, had more extensive coronary disease, and were more likely to have received warfarin after stenting. Only 1 (0.6%, 95% CI 0.0%-3.4%) of 164 patients had an event (stent thrombosis causing myocardial infarction) during the first week after minor surgery; this rate was slightly higher than the background rate of ischemic events in the study population (exact mid P = .01). Clopidogrel use at 12 months was similar between patients who did and those who did not undergo minor surgery (65.2% vs 65.5%, P = .95). In the EVENT Registry, minor surgery was performed in 2% of patients in the first year after DES implantation. The risk of stent thrombosis during the first week after surgery was increased slightly compared with background rates, but the absolute event rate was low (0.6%).

Rapid adoption of drug-eluting stents: Clinical practices and outcomes from the early drug-eluting stent era

We sought to evaluate the early drug-eluting stent (DES) era, characterized by widespread device use. Contemporary clinical practice incorporating more selective DES use can only be assessed by understanding the early DES era. All patients receiving DES during the first 3 waves of the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) Registry (2004-2006) were evaluated. The primary end point was a composite of death, myocardial infarction (MI), and urgent revascularization at discharge and death, MI, or target lesion revascularization (TLR) at 1 year. The composite end point at each time point was compared across waves. Multivariable logistic regression was used for in-hospital outcomes and multivariable Cox regression was used for 1-year end points. Ninety-two percent of EVENT patients received at least one DES. One third of patients were treated for Acute Coronary Syndromes (ACS) (33.8%), and later waves included lower lesion complexity. Across waves there was more frequent clopidogrel loading, a decrease in heparin and an increase in bivalirudin use (all P < .01). The primary composite end point of in-hospital death, MI or urgent revascularization occurred in 7.2% of patients, and did not differ across waves. Despite remarkably high levels of routine DES usage, the composite end point of death, MI, or TLR at 1 year averaged 13.5% and did not differ across waves. After adjustment, no statistically significant effect of wave on composite bleeding (P = .068) as well as in-hospital TLR (P = .053) was noted. At 1 year, wave was associated with a lower likelihood of TLR in the adjusted model (HR 0.81, P = .03). The high-adoption DES era was associated with favorable outcomes, decreasing bleeding rates and changes in antithrombotic approach.

Frequency of Major Noncardiac Surgery and Subsequent Adverse Events in the Year After Drug-Eluting Stent Placement: Results From the EVENT (Evaluation of Drug-Eluting Stents and Ischemic Events) Registry

This study sought to determine the frequency of noncardiac surgery and adverse post-operative events among patients who recently received a drug-eluting stent (DES) following noncardiac surgery. Little is known about frequency of and risks associated with noncardiac surgery after DES implantation. In the EVENT (Evaluation of Drug-Eluting Stents and Ischemic Events) registry, consecutive patients who underwent attempted stent placement at 42 hospitals between July 2004 and September 2005 were enrolled and followed for 1 year. In this study, we analyzed patients who received ≥ 1 DES to determine the frequency of noncardiac surgery and cardiac death, myocardial infarction, or stent thrombosis in the following week. Among 4,637 DES recipients, 206 (4.4%) underwent major noncardiac surgery in the following year (median days to surgery: 179 [interquartile range 112 to 266 days; range 13 to 360 days]). Overall, stent use averaged 1.5 per patient. The most frequent operations were orthopedic (36%), abdominal (31%), and vascular (20%). Compared with patients who did not undergo surgery, those who did were older, more likely to be women, and have had a prior stroke; the frequencies of prior myocardial infarction, prior coronary artery bypass graft, and diabetes were similar, as were left ventricular ejection fraction and indication for percutaneous coronary intervention. In the 7 days after surgery, 4 patients had a cardiac death, myocardial infarction, or stent thrombosis (1.9% [exact 95% confidence interval (CI): 0.5% to 4.9%]). The risk of the composite outcome was increased 27-fold in the week following noncardiac surgery compared with any other week after stent implantation (hazard ratio [HR]: 27.3 [95% CI: 10.0 to 74.2], p < 0.001). The frequency of major noncardiac surgery in the year after DES placement is >4%. Although the overall risk of adverse outcomes was less than previously reported when surgery is performed months after DES placement, it is significantly increased in the week after major noncardiac surgery.

Prognostic Impact of Periprocedural Bleeding and Myocardial Infarction After Percutaneous Coronary Intervention in Unselected Patients: Results From the EVENT (Evaluation of Drug-Eluting Stents and Ischemic Events) Registry

Our aim was to examine the prognostic importance of hemorrhagic and ischemic complications after percutaneous coronary intervention (PCI) in unselected patients. In randomized trials of PCI, major bleeding and periprocedural myocardial infarction (pMI) have been associated with increased mortality. Whether similar associations exist among un-selected PCI patients is unknown. We used data from the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) registry-a multicenter registry of unselected patients undergoing PCI-to examine the association between both in-hospital bleeding and pMI and 1-year mortality. Cardiac enzyme levels were assessed in all patients, and pMI was defined as a peak creatine kinase-MB value >or=3x the upper limit of normal. Post-PCI bleeding was classified by Thrombolysis In Myocardial Infarction criteria. After excluding patients with elevated pre-PCI creatine kinase-MB values and ST-segment elevation myocardial infarction at presentation (n = 1,626), a total of 5,961 patients were available for evaluation. Rates of post-PCI bleeding and pMI were 3.0% and 7.1%, respectively; 1-year all-cause mortality was 2.8%. After multivariable adjustment, both post-PCI bleeding (adjusted hazard ratio [HR]: 3.83, 95% confidence interval: 2.48 to 5.90, p < 0.001) and pMI (adjusted HR: 1.84, 95% confidence interval: 1.17 to 2.89, p = 0.009) were independently associated with 1-year mortality. Time period-specific analyses demonstrated that the adjusted HR for bleeding was similar for 30-day mortality and mortality between 1 month and 1 year, while the adjusted HR for pMI was greater for 30-day mortality as compared with mortality between 1 month and 1 year. Among unselected PCI patients, both post-PCI bleeding and pMI are independently associated with increased 1-year mortality. Continued efforts to reduce these complications after PCI are warranted.

In-Hospital and 1-Year Outcomes Among Unselected Percutaneous Coronary Intervention Patients Treated With Either Sirolimus- or Paclitaxel-Eluting Stents: Results From the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) Registry

The aim of this study was to compare outcomes among unselected patients undergoing percutaneous coronary intervention (PCI) with either sirolimus-eluting (SES) or paclitaxel-eluting stents (PES). Although the benefits of both SES and PES are well-established, studies comparing these stents directly have yielded conflicting results. We used data from the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) registry to compare in-hospital and 1-year outcomes among unselected patients undergoing nonemergent PCI with either SES or PES implantation. Between July 2004 and June 2006, 6,035 patients underwent PCI with either SES (n = 3,443) or PES (n = 2,592) at 47 U.S. centers. Baseline clinical and angiographic characteristics were generally similar for the 2 stent types. At 1-year, there were no differences in the primary end point of cardiac death or myocardial infarction (MI) between the SES and PES groups (9.1% vs. 10.0%, p = 0.11) or in any individual end points including cardiac death, nonfatal MI, or stent thrombosis. In unadjusted analyses, target lesion revascularization (TLR) was slightly more common with SES than with PES (4.4% vs. 3.3%, p = 0.048), but this difference was no longer apparent after adjusting for baseline characteristics as well as site-related factors (adjusted hazard ratio: 1.09, 95% confidence interval: 0.78 to 1.50). Among unselected patients undergoing PCI, adjusted rates of both ischemic complications as well as clinically important restenosis were similar for SES and PES. The unexpected finding that TLR was influenced by site characteristics suggests that the correlation between TLR and angiographic restenosis might be weaker than previously described and warrants further study.

In-Hospital and 1-Year Outcomes Among Percutaneous Coronary Intervention Patients With Chronic Kidney Disease in the Era of Drug-Eluting Stents: A Report From the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) Registry

This study sought to evaluate ischemic and bleeding outcomes in patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Previous studies have shown that CKD is associated with poor outcomes after PCI. However, these studies were largely conducted before the introduction of DES and aggressive antithrombotic therapy or were performed in the setting of randomized trials. With data from a contemporary registry, we evaluated the influence of CKD on major cardiovascular events and bleeding complications in unselected "real-world" patients undergoing PCI. Data from 4,791 patients enrolled in the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) Registry between July 2004 and September 2005 were analyzed. Patients were stratified into 4 groups: creatinine clearance (CrCl) >75, 50 to 75, 30 to 49 and <30 ml/min. During the index hospital stay, there was a step-wise increase in bleeding complications with decreasing CrCl (3.3%, 5.0%, 8.8%, and 14.3%; p < 0.0001 for trend). Lower CrCl was also associated with more frequent death or myocardial infarction (MI) during the initial hospital stay (p = 0.001) and at 1 year (p < 0.001). These findings were confirmed in multivariate analyses that adjusted for baseline differences in demographic, clinical, and angiographic factors. Use of guideline-recommended medications at 1 year, including aspirin, clopidogrel, angiotensin-converting enzyme inhibitors, and statins, also decreased with declining renal function. Renal function is an independent and powerful predictor of bleeding and ischemic complications in the era of DES and contemporary antithrombotic therapy in patients undergoing PCI. The low use of guideline-recommended drugs among patients with CKD undergoing PCI might contribute to these adverse outcomes and warrants further evaluation.

Biomarker Release After Percutaneous Coronary Intervention

Cardiac biomarkers of necrosis provide clinicians with important “messages” from the heart. They are released into the interstitium of the myocardium after loss of the integrity of cardiac myocyte membranes. The pattern of the rise and fall of an individual biomarker (ie, its release kinetics) depends on its intracellular location in the myocyte, molecular weight, and clearance from the interstitium of the myocardium and ultimately the circulation.1 Cardiac biomarkers play an integral role in the clinical diagnosis of myocardial infarction (MI). Referring to the spontaneous occurrence of MI in patients, the World Health Organization required that at least 2 of the following be present to fulfill the criteria for MI: a history of ischemia-type chest discomfort, evolutionary changes on serially obtained ECG tracings, and a rise and fall in serum cardiac markers.2 Article see p 10 See Editorial Circulation . 2008;118:609–611 See Article Circulation . 2008;118:632–638 Several dramatic advances have occurred in the biomarker component of the diagnosis of MI. Analytes with greater specificity for the myocardium were introduced into clinical medicine, with creatine kinase-MB replacing total creatine kinase and subsequently cardiac-specific troponins replacing creatine kinase-MB as the biomarker of choice for diagnosing MI.3 Assay technology improved as clinical chemists moved from enzymatic activity assays for CK to highly specific immunoassays that can detect progressively smaller concentrations of cardiac troponins in the peripheral circulation.4 Although ST-elevation MI (STEMI) is easily identified on the 12-lead ECG, we now recognize that many patients previously diagnosed with unstable angina are more properly diagnosed as having non–ST-elevation MI (NSTEMI) on the basis of the detection of elevated levels of cardiac troponins in their blood.5 Cardiac biomarkers are used as a rough guide to the extent of myocardial necrosis. The higher the peak biomarker level after STEMI, the larger the …