Scot Garg

Coronary Stents: Current Status

Coronary artery stents revolutionized the practice of interventional cardiology after they were first introduced in the mid-1980s. Since then, there have been significant developments in their design, the most notable of which has been the introduction of drug-eluting stents. This paper reviews the benefits, risks, and current status of Food and Drug Administration-approved drug-eluting stents.

Assessment of the SYNTAX score in the Syntax study

AIMSnThe SYNTAX score has been designed to better anticipate the risks of percutaneous or surgical revascularisation, taking into account the functional impact of the coronary circulation with all its anatomic components including the presence of bifurcations, total occlusions, thrombus, calcification, and small vessels. The purpose of this paper is to describe the baseline assessment of the SYNTAX score in the Syntax randomised trial, the corelab reproducibility, the potential difference in score assessment between the investigator and the corelab, and to ascertain the impact on one-year outcome after either percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) in patients with complex coronary artery disease.nnnMETHODS AND RESULTSnTo assess the reliability of Syntax scoring, 100 diagnostic angiograms from the Syntax trial were randomly selected and assessed independently by two observers. Intra-observer variability was assessed by analysing 91 sets of angiograms after an interval of at least eight weeks by one of the observers. Clinical outcomes in the randomised cohort of the Syntax trial up to one year are presented with stratification by tertile group of the SYNTAX score. The weighted kappa value for the inter-observer reproducibility on the global score was 0.45, while the intra-observer weighted kappa value was 0.59. The SYNTAX score as calculated by investigators consistently underscored the corelab score by 3.4 points. When the Syntax randomised cohort was stratified by tertiles of the SYNTAX score, there were similar or non-significantly different MACCE rates in those with low or intermediate scores; however in the top tertile the MACCE rate was greater in those receiving PCI compared to CABG.nnnCONCLUSIONSnThe SYNTAX score is a visual coronary score with an acceptable corelab reproducibility that has an impact on the one-year outcome of those having PCI, whereas it has no effect on the one-year outcome following surgical revascularisation. The SYNTAX score tool is likely to be useful in a wide range of patients with complex coronary disease.

Coronary Stents: Looking Forward

Despite all the benefits of drug-eluting stents (DES), concerns have been raised over their long-term safety, with particular reference to stent thrombosis. In an effort to address these concerns, newer stents have been developed that include: DES with biodegradable polymers, DES that are polymer free, stents with novel coatings, and completely biodegradable stents. Many of these stents are currently undergoing pre-clinical and clinical trials; however, early results seem promising. This paper reviews the current status of this new technology, together with other new coronary devices such as bifurcation stents and drug-eluting balloons, as efforts continue to design the ideal coronary stent.

5-Year Clinical Outcomes of the ARTS II (Arterial Revascularization Therapies Study II) of the Sirolimus-Eluting Stent in the Treatment of Patients With Multivessel De Novo Coronary Artery Lesions

OBJECTIVESnThe purpose of this study is to compare the 5-year clinical outcomes, safety, and efficacy of sirolimus-eluting stents (SES) in the ARTS II (Arterial Revascularization Therapies Study II) with the outcomes of coronary artery bypass graft (CABG) and bare-metal stenting (BMS) from the ARTS I.nnnBACKGROUNDnThe long-term outcomes after SES implantation in patients with multivessel disease remains to be established.nnnMETHODSnThe ARTS I was a randomized trial of 1,205 patients with multivessel disease comparing CABG and BMS. The ARTS II study was a nonrandomized trial with the Cypher sirolimus-eluting stent (Cordis, a Johnson & Johnson Company, Warren, New Jersey), applying the same inclusion and exclusion criteria, end points, and protocol definitions. The ARTS II trial enrolled 607 patients, with an attempt to enroll at least one-third of patients with 3-vessel disease.nnnRESULTSnAt 5-year, the death/stroke/myocardial infarction event-free survival rate was 87.1% in ARTS II SES, versus 86.0% (p = 0.1) and 81.9% (p = 0.007) in ARTS I CABG and BMS cohorts, respectively. The 5-year major adverse cardiac and cerebrovascular event (MACCE) rate in ARTS II (27.5%) was significantly higher than ARTS I CABG (21.1%, p = 0.02), and lower than in ARTS I BMS (41.5%, p < 0.001). The cumulative incidence of definite stent thrombosis was 3.8%. Thirty-two percent (56 of 176) of major adverse cardiac events (MACE) at 5 years were related to possible, probable, or definite stent thrombosis.nnnCONCLUSIONSnAt 5 years, SES had a safety record comparable to CABG and superior to BMS, and a MACCE rate that was higher than in patients treated with CABG, and lower than in those treated with BMS. Approximately one-third of the events seen with SES could be prevented through the elimination of early, late, and very late stent thrombosis.

Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial

OBJECTIVESnWe aimed to assess the predictive value of the SYNTAX score (SXscore) for major adverse cardiac events in the all-comers population of the LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial.nnnBACKGROUNDnThe SXscore has been shown to be an effective predictor of clinical outcomes in patients with multivessel disease undergoing percutaneous coronary intervention.nnnMETHODSnThe SXscore was prospectively collected in 1,397 of the 1,707 patients enrolled in the LEADERS trial (patients after surgical revascularization were excluded). Post hoc analysis was performed by stratifying clinical outcomes at 1-year follow-up, according to 1 of 3 SXscore tertiles.nnnRESULTSnThe 1,397 patients were divided into tertiles based on the SXscore in the following fashion: SXscore<or=8 (SXlow) (n=464), SXscore>8 and <or=16 (SXmid) (n=472), and SXscore>16 (SXhigh) (n=461). At 1-year follow-up, there was a significantly lower number of patients with major cardiac event-free survival in the highest tertile of SXscore (SXlow=92.2%, SXmid=91.1%, and SXhigh=84.6%; p<0.001). Death occurred in 1.5% of SXlow patients, 2.1% of SXmid patients, and 5.6% of SXhigh patients (hazard ratio [HR]: 1.97, 95% confidence interval [CI]: 1.29 to 3.01; p=0.002). The myocardial infarction rate tended to be higher in the SXhigh group. Target vessel revascularization was 11.3% in the SXhigh group compared with 6.3% and 7.8% in the SXlow and SXmid groups, respectively (HR: 1.38, 95% CI: 1.1 to 1.75; p=0.006). Composite of cardiac death, myocardial infarction, and clinically indicated target vessel revascularization was 7.8%, 8.9%, and 15.4% in the SXlow, SXmid, and SXhigh groups, respectively (HR: 1.47, 95% CI: 1.19 to 1.81; p<0.001).nnnCONCLUSIONSnThe SXscore, when applied to an all-comers patient population treated with drug-eluting stents, may allow prospective risk stratification of patients undergoing percutaneous coronary intervention. (LEADERS Trial Limus Eluted From A Durable Versus ERodable Stent Coating; NCT00389220).

A New Tool for the Risk Stratification of Patients With Complex Coronary Artery Disease The Clinical SYNTAX Score

Background—Presently, no effective risk model exists to predict long-term mortality or other major adverse cardiovascular and cerebrovascular events (MACCE) in those patients undergoing percutaneous coronary intervention (PCI). This study aimed to assess whether the Clinical SYNTAX Score (CSS) calculated by multiplying the SYNTAX Score to a modified ACEF score (age/ejection fraction +1 for each 10 mL the creatinine clearance <60 mL/min per 1.73 m2) would improve the ability of either score to predict mortality and MACCE. Methods and Results—The CSS was calculated in 512 patients enrolled in the ARTS-II study who had serum creatinine levels, ejection fraction, and body weight recorded at baseline. Clinical outcomes in terms of MACCE and mortality at 1- and 5-year follow-up were stratified according to CSS tertiles: CSSLOW⩽15.6 (n=170), 15.627.5 (n=171). At 1-year follow-up, rates of repeat revascularization and MACCE were significantly higher in the highest tertile group. At 5-year follow-up, CSSHIGH had a comparable rate of myocardial infarction, a trend toward a significantly higher rate of death, and significantly higher rates of repeat revascularization and overall MACCE compared with patients in the lower 2 tertiles. The respective C-statistics for the CSS, SYNTAX Score, and ACEF score for 5-year mortality were 0.69, 0.62, and 0.65 and for 5-year MACCE were 0.62, 0.59, and 0.57. Conclusions—An improvement in the ability of the SYNTAX Score to predict MACCE and mortality can be achieved by combining the SYNTAX Score with a simple clinical risk score incorporating age, ejection fraction, and creatinine clearance to produce the Clinical SYNTAX score. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00235170.

SYNTAX score and Clinical SYNTAX score as predictors of very long-term clinical outcomes in patients undergoing percutaneous coronary interventions: a substudy of SIRolimus-eluting stent compared with pacliTAXel-eluting stent for coronary revascularization (SIRTAX) trial

AIMSnTo investigate the ability of SYNTAX score and Clinical SYNTAX score (CSS) to predict very long-term outcomes in an all-comers population receiving drug-eluting stents.nnnMETHODS AND RESULTSnThe SYNTAX score was retrospectively calculated in 848 patients enrolled in the SIRolimus-eluting stent compared with pacliTAXel-Eluting Stent for coronary revascularization (SIRTAX) trial. The CSS was calculated using age, and baseline left ventricular ejection fraction and creatinine clearance. A stratified post hoc comparison was performed for all-cause mortality, cardiac death, myocardial infarction (MI), ischaemia-driven target lesion revascularization (TLR), definite stent thrombosis, and major adverse cardiac events (MACE) at 1- and 5-year follow-up. Tertiles for SYNTAX score and CSS were defined as SS(LOW) ≤ 7, 7< SS(MID) ≤ 14, SS(HIGH) >14 and CSS(LOW) ≤ 8.0, 8.0 17.0, respectively. Major adverse cardiac events rates were significantly higher in SS(HIGH) compared with SS(LOW) at 1- and 5-year follow-up, which was also seen at 5 years for all-cause mortality, cardiac death, MI, and TLR. Stratifying outcomes across CSS tertiles confirmed and augmented these results. Within CSS(HIGH), 5-year MACE increased with use of paclitaxel- compared with sirolimus-eluting stents (34.7 vs. 21.3%, P = 0.008). SYNTAX score and CSS were independent predictors of 5-year MACE; CSS was an independent predictor for 5-year mortality. Areas-under-the-curve for SYNTAX score and CSS for 5-year MACE were 0.61 (0.56-0.65) and 0.62 (0.57-0.67), for 5-year all-cause mortality 0.58 (0.51-0.65) and 0.66 (0.59-0.73) and for 5-year cardiac death 0.63 (0.54-0.72) and 0.72 (0.63-0.81), respectively.nnnCONCLUSIONnSYNTAX score and to a greater extent CSS were able to stratify risk for very long-term adverse clinical outcomes in an all-comers population receiving drug-eluting stents. Predictive accuracy for 5-year all-cause mortality was improved using CSS.nnnTRIAL REGISTRATION NUMBERnNCT00297661.

A comparison of the conformability of everolimus-eluting bioresorbable vascular scaffolds to metal platform coronary stents

OBJECTIVESnThe aim of this study was to assess the differences in terms of curvature and angulation of the treated vessel after the deployment of either a metallic stent or a polymeric scaffold device.nnnBACKGROUNDnConformability of metallic platform stents (MPS) is the major determinant of geometric changes in coronary arteries caused by the stent deployment. It is not known how bioresorbable polymeric devices perform in this setting.nnnMETHODSnThis retrospective study compares 102 patients who received an MPS (Multi-link Vision or Xience V, Abbott Vascular, Santa Clara, California) in the SPIRIT FIRST and II trials with 89 patients treated with the Revision 1.1 everolimus-eluting bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) from cohort B of the ABSORB (A bioabsorbable everolimus-eluting coronary stent system) trial. All patients were treated with a single 3 × 18 mm device. Curvature and angulation were measured with dedicated software by angiography.nnnRESULTSnBoth the MPS and BVS groups had significant changes in relative region curvature (MPS vs. BVS: 28.7% vs. 7.5%) and angulation (MPS vs. BVS: 25.4% vs. 13.4%) after deployment. The unadjusted comparisons between the 2 groups showed for BVS a nonsignificant trend for less change in region curvature after deployment (MPS vs. BVS: 0.085 cm(-1) vs. 0.056 cm(-1), p = 0.06) and a significantly lower modification of angulation (MPS vs. BVS 6.4° vs. 4.3°, p = 0.03). By multivariate regression analysis, the independent predictors of changes in curvature and angulation were the pre-treatment region curvature, the pre-treatment region angulation, and the used device.nnnCONCLUSIONSnBioresorbable vascular scaffolds have better conformability than conventional MPS. The clinical significance of the observed differences will require further investigation.

Prediction of 1-year clinical outcomes using the SYNTAX score in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVESnThis study sought to evaluate the impact of SYNTAX score (SXscore), and compare its performance in isolation and combination with the PAMI (The Primary Angioplasty in Myocardial Infarction Study) score, for the prediction of 1-year clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention.nnnBACKGROUNDnPatients with STEMI were excluded from the original SYNTAX score (SXscore) algorithm. Therefore, the utility of using the SXscore in this patient group remains undefined.nnnMETHODSnSXscore was calculated retrospectively in 807 patients with STEMI enrolled in the randomized STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) clinical trials. Clinical outcomes of all-cause death, reinfarction, and clinically driven target vessel revascularization were subsequently stratified according to SXscore tertiles: SX(LOW) ≤ 9 (n = 311), 9 < SX(MID) ≤ 16 (n = 234), SX(HIGH) >16 (n = 262).nnnRESULTSnAt 1-year follow-up, all clinical outcomes including mortality, mortality/reinfarction, major adverse cardiac events (MACE) (a composite of all-cause death, reinfarction and target vessel revascularization), and definite, definite/probable, and any stent thrombosis were all significantly higher in patients in the highest SXscore tertile. SXscore was identified as an independent predictor of mortality, MACE, and stent thrombosis out to 1-year follow-up. The combination SYNTAX-PAMI score led to a net reclassification improvement of 15.7% and 4.6% for mortality and MACE, respectively. The C-statistics for the SXscore, PAMI score, and the combined SYNTAX-PAMI score were 0.65, 0.81, and 0.73 for 1-year mortality, and 0.68, 0.64, and 0.69 for 1-year MACE, respectively.nnnCONCLUSIONSnSXscore does have a role in the risk stratification of patients with STEMI having primary percutaneous coronary intervention; however, this ability can be improved through a combination with clinical variables. (Multicentre 2×2 Factorial Randomised Study Comparing Tirofiban Versus Abciximab and SES Versus BMS in AMI; NCT00229515).

The SYNTAX score revisited: A reassessment of the SYNTAX score reproducibility

Objectives: To reassess the reproducibility of the SYNTAX score. Background: The SYNTAX score appears to have an important role to play in the evaluation of patients with complex coronary artery disease undergoing revascularisation. However, the calculation of the SYNTAX score relies on the subjective assessment of lesions using coronary angiography, and therefore is subject to intra‐and inter‐observer variability. Methods: The SYNTAX score was calculated in 100 patients randomly selected from the SYNTAX trial, on two occasions 8 weeks apart, by a team made up of three interventional cardiologists. The weighted kappa values were compared with values obtained 1 year previously, when core lab analysts assessed the intra‐observer reproducibility amongst the same patient cohort. Results: The mean ± standard deviation difference in SYNTAX score was 2.1 ± 7.6. The respective weighted kappa values for the number of lesions, bifurcation lesions, ostial lesions, and total occlusions were 0.62, 0.36, 0.66, and 0.91 compared with 0.59, 0.41, 0.63, and 0.82 in the previous core lab assessment. The weighted kappa for the intra‐observer reproducibility of the SYNTAX score grouped into deciles was 0.54, and according to the terciles ≤22, >22–≤32, >32 was 0.51 both indicating a moderate level of agreement beyond the level of chance. In the previous assessment, the comparative kappa values were 0.45 and 0.53. Conclusions: The SYNTAX score has moderate intra‐observer reproducibility when assessed by a team of three interventional cardiologists, which is consistent with a prior evaluation performed by core lab analysts. The scoring of bifurcation lesions remains the main source of inconsistency.