Pascal Vranckx

Clinical End Points in Coronary Stent Trials A Case for Standardized Definitions

Background— Although most clinical trials of coronary stents have measured nominally identical safety and effectiveness end points, differences in definitions and timing of assessment have created confusion in interpretation. Methods and Results— The Academic Research Consortium is an informal collaboration between academic research organizations in the United States and Europe. Two meetings, in Washington, DC, in January 2006 and in Dublin, Ireland, in June 2006, sponsored by the Academic Research Consortium and including representatives of the US Food and Drug Administration and all device manufacturers who were working with the Food and Drug Administration on drug-eluting stent clinical trial programs, were focused on consensus end point definitions for drug-eluting stent evaluations. The effort was pursued with the objective to establish consistency among end point definitions and provide consensus recommendations. On the basis of considerations from historical legacy to key pathophysiological mechanisms and relevance to clinical interpretability, criteria for assessment of death, myocardial infarction, repeat revascularization, and stent thrombosis were developed. The broadly based consensus end point definitions in this document may be usefully applied or recognized for regulatory and clinical trial purposes. Conclusion— Although consensus criteria will inevitably include certain arbitrary features, consensus criteria for clinical end points provide consistency across studies that can facilitate the evaluation of safety and effectiveness of these devices.

Updated standardized endpoint definitions for transcatheter aortic valve implantation: The Valve Academic Research Consortium-2 consensus document

OBJECTIVESnThe aim of the current Valve Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI) clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand the understanding of patient risk stratification and case selection.nnnBACKGROUNDnA recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous.nnnMETHODS AND RESULTSnTwo in-person meetings (held in September 2011 in Washington, DC, and in February 2012 in Rotterdam, The Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and noninterventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the US Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document provides an overview of risk assessment and patient stratification that need to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding complications, acute kidney injury, vascular complications, conduction disturbances and arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiographic recommendations are provided for the evaluation of prosthetic valve (dys)function. Definitions for the quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints.nnnCONCLUSIONSnThis VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of the study results, supplying an increasingly growing body of evidence with respect to TAVI and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavors of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).

Standardized Endpoint Definitions for Transcatheter Aortic Valve Implantation Clinical Trials : A Consensus Report From the Valve Academic Research Consortium

Objectives To propose standardized consensus definitions for important clinical endpoints in transcatheter aortic valve implantation (TAVI), investigations in an effort to improve the quality of clinical research and to enable meaningful comparisons between clinical trials. To make these consensus definitions accessible to all stakeholders in TAVI clinical research through a peer reviewed publication, on behalf of the public health. Background Transcatheter aortic valve implantation may provide a worthwhile less invasive treatment in many patients with severe aortic stenosis and since its introduction to the medical community in 2002, there has been an explosive growth in procedures. The integration of TAVI into daily clinical practice should be guided by academic activities, which requires a harmonized and structured process for data collection, interpretation, and reporting during well-conducted clinical trials. Methods and results The Valve Academic Research Consortium established an independent collaboration between Academic Research organizations and specialty societies (cardiology and cardiac surgery) in the USA and Europe. Two meetings, in San Francisco, California (September 2009) and in Amsterdam, the Netherlands (December 2009), including key physician experts, and representatives from the US Food and Drug Administration (FDA) and device manufacturers, were focused on creating consistent endpoint definitions and consensus recommendations for implementation in TAVI clinical research programs. Important considerations in developing endpoint definitions included (i) respect for the historical legacy of surgical valve guidelines; (ii) identification of pathophysiological mechanisms associated with clinical events; (iii) emphasis on clinical relevance. Consensus criteria were developed for the following endpoints: mortality, myocardial infarction, stroke, bleeding, acute kidney injury, vascular complications, and prosthetic valve performance. Composite endpoints for TAVI safety and effectiveness were also recommended. Conclusion Although consensus criteria will invariably include certain arbitrary features, an organized multidisciplinary process to develop specific definitions for TAVI clinical research should provide consistency across studies that can facilitate the evaluation of this new important catheter-based therapy. The broadly based consensus endpoint definitions described in this document may be useful for regulatory and clinical trial purposes.

Stent thrombosis and major clinical events at 3 years after zotarolimus-eluting or sirolimus-eluting coronary stent implantation: a randomised, multicentre, open-label, controlled trial.

BACKGROUNDnWe sought to compare the long-term safety of two devices with different antiproliferative properties: the Endeavor zotarolimus-eluting stent (E-ZES; Medtronic, Inc) and the Cypher sirolimus-eluting stent (C-SES; Cordis, Johnson & Johnson) in a broad group of patients and lesions.nnnMETHODSnBetween May 21, 2007 and Dec 22, 2008, we recruited 8791 patients from 36 recruiting countries to participate in this open-label, multicentre, randomised, superiority trial. Eligible patients were those aged 18 years or older undergoing elective, unplanned, or emergency procedures in native coronary arteries. Patients were randomly assigned to either receive E-ZES and C-SES (ratio 1:1). Randomisation was stratified per centre with varying block sizes of four, six, or eight patients, and concealed with a central telephone-based or web-based allocation service. The primary outcome was definite or probable stent thrombosis at 3 years and was analysed by intention to treat. Patients and investigators were aware of treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT00476957.nnnFINDINGSnPROTECT randomised 8791 patients, of whom 8709 provided consent to participate and were eligible: 4357 were allocated to the E-ZES group and 4352 patients to the C-SES group. At 3 years, rates of definite or probable stent thrombosis did not differ between groups (1·4% for E-ZES [predicted: 1·5%] vs 1·8% [predicted: 2·5%] for C-SES; hazard ratio [HR] 0·81, 95% CI 0·58-1·14, p=0·22). Dual antiplatelet therapy was used in 8402 (96%) patients at discharge, 7456 (88%) at 1 year, 3041 (37%) at 2 years, and 2364 (30%) at 3 years.nnnINTERPRETATIONnNo evidence of superiority of E-ZES compared with C-SES in definite or probable stent thrombosis rates was noted at 3 years. Time analysis suggests a difference in definite or probable stent thrombosis between groups is emerging over time, and a longer follow-up is therefore needed given the clinical relevance of stent thrombosis.nnnFUNDINGnMedtronic, Inc.

Combined anatomical and clinical factors for the long-term risk stratification of patients undergoing percutaneous coronary intervention: the Logistic Clinical SYNTAX score

BACKGROUNDnThe SYNTAX score (SXscore), an anatomical-based scoring tool reflecting the complexity of coronary anatomy, has established itself as an important long-term prognostic factor in patients undergoing percutaneous coronary intervention (PCI). The incorporation of clinical factors may further augment the utility of the SXscore to longer-term risk stratify the individual patient for clinical outcomes.nnnMETHODS AND RESULTSnPatient-level merged data from >6000 patients in seven contemporary coronary stent trials was used to develop a logistic regression model-the Logistic Clinical SXscore-to predict 1-year risk for all-cause death and major adverse cardiac events (MACE). A core model (composed of the SXscore, age, creatinine clearance, and left ventricular ejection fraction) and an extended model [incorporating the core model and six additional (best performing) clinical variables] were developed and validated in a cross-validation procedure. The core model demonstrated a substantial improvement in predictive ability for 1-year all-cause death compared with the SXscore in isolation [area under the receiver operator curve (AUC): core model: 0.753, SXscore: 0.660]. A minor incremental benefit of the extended model was shown (AUC: 0.791). Consequently the core model alone was retained in the final the Logistic Clinical SXscore model. Validation plots confirmed the model predictions to be well calibrated. For 1-year MACE, the addition of clinical variables did not improve the predictive ability of the SXscore, secondary to the SXscore being the predominant determinant of all-cause revascularization.nnnCONCLUSIONnThe Logistic Clinical SXscore substantially enhances the prediction of 1-year mortality after PCI compared with the SXscore, and allows for an accurate personalized assessment of patient risk.

Clinical introduction of the Tandemheart, a percutaneous left ventricular assist device, for circulatory support during high-risk percutaneous coronary intervention

BACKGROUND: In patients with poor left ventricular function and high-risk coronary lesions, prolonged ischemia during percutaneous coronary intervention (PCI) may have major hemodynamic consequences. The Tandemheart is a percutaneous left ventricular assist device intended for short-term circulatory support. METHODS AND RESULTS: The Tandem-heart incorporates 9-17 F. arterial cannulae and a unique 21 F. transseptal cannula and centrifugal bloodpump. Operating at 7500 rpm, the pump withdraws oxygenated blood from the left atrium and delivers up to 4 liters/min to the arterial circulation. As of May 2001, the Tandem-heart was electively employed in three male patients (ages 52, 54 and 56) scheduled for high-risk PCI. The mean time to initial circulatory support was less than 30 minutes. Systemic hemodynamics significantly improved prior to PCI in two patients. Pump flow after one hour ranged from 2.43 to 3.8 liters/min (mean 3.17 liters/min) and duration of support from 23 to 49 hours (mean 33 hours). Procedural success was 100%, with no significant hemolysis or bleeding. Successful weaning was completed in all patients, who have remained free of major cardiac events up to seven months post-PCI. CONCLUSIONS: In this first clinical experience of elective use of Tandem-heart for circulatory support during high-risk PCI, the device was easily inserted and preserved hemodynamic stability, regardless of the intrinsic cardiac function, creating optimism for more widespread use for this and other indications.

A Global Risk Approach to Identify Patients With Left Main or 3-Vessel Disease Who Could Safely and Efficaciously Be Treated With Percutaneous Coronary Intervention : The SYNTAX Trial at 3 Years

OBJECTIVESnThe aim of this study was to assess the additional value of the Global Risk--a combination of the SYNTAX Score (SXscore) and additive EuroSCORE--in the identification of a low-risk population, who could safely and efficaciously be treated with coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI).nnnBACKGROUNDnPCI is increasingly acceptable in appropriately selected patients with left main stem or 3-vessel coronary artery disease.nnnMETHODSnWithin the SYNTAX Trial (Synergy between PCI with TAXUS and Cardiac Surgery Trial), all-cause death and major adverse cardiac and cerebrovascular events (MACCE) were analyzed at 36 months in low (GRC(LOW)) to high Global Risk groups, with Kaplan-Meier, log-rank, and Cox regression analyses.nnnRESULTSnWithin the randomized left main stem population (n = 701), comparisons between GRC(LOW) groups demonstrated a significantly lower mortality with PCI compared with CABG (CABG: 7.5%, PCI: 1.2%, hazard ratio [HR]: 0.16, 95% confidence interval [CI]: 0.03 to 0.70, p = 0.0054) and a trend toward reduced MACCE (CABG: 23.1%, PCI: 15.8%, HR: 0.64, 95% CI: 0.39 to 1.07, p = 0.088). Similar analyses within the randomized 3-vessel disease population (n = 1,088) demonstrated no statistically significant differences in mortality (CABG: 5.2%, PCI: 5.8%, HR: 1.14, 95% CI: 0.57 to 2.30, p = 0.71) or MACCE (CABG: 19.0%, PCI: 24.7%, HR: 1.35, 95% CI: 0.95 to 1.92, p = 0.10). Risk-model performance and reclassification analyses demonstrated that the EuroSCORE-with the added incremental benefit of the SXscore to form the Global Risk-enhanced the risk stratification of all PCI patients.nnnCONCLUSIONSnIn comparison with the SXscore, the Global Risk, with a simple treatment algorithm, substantially enhances the identification of low-risk patients who could safely and efficaciously be treated with CABG or PCI.

Incidence and multivariable correlates of long-term mortality in patients treated with surgical or percutaneous revascularization in the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) trial

AIMSnThe aim of this investigation was to determine the incidence and multivariable correlates of long-term (4-year) mortality in patients treated with surgical or percutaneous revascularization in the synergy between percutaneous coronary intervention (PCI) with TAXUS Express and Cardiac Surgery (SYNTAX) trial.nnnMETHODS AND RESULTSnA total of 1800 patients were randomized to undergo coronary artery bypass graft (CABG) surgery (n = 897) or PCI (n = 903). Prospectively collected baseline and peri- and post-procedural data were used to determine independent correlates of 4-year all-cause death in the CABG and the PCI arms (Cox proportional hazards model). Four-year mortality rates in the CABG and the PCI arms were 9.0% [74 deaths (12 in-hospital)] and 11.8% [104 deaths (16 in-hospital)], respectively (log-rank P-value = 0.063). Censored data comprised 78 patients (8.7%) in the CABG arm, and 24 patients (2.7%) in the PCI arm (log-rank P-value < 0.001). Within the CABG arm, the strongest independent correlates of 4-year mortality were lack of discharge aspirin [hazard ratio (HR) 3.56; 95% CI: 2.04, 6.21; P < 0.001], peripheral vascular disease (PVD) (HR: 2.65; 95% CI: 1.49, 4.72; P = 0.001), chronic obstructive pulmonary disease, age, and serum creatinine. Within the PCI arm, the strongest independent correlate of 4-year mortality was lack of post-procedural anti-platelet therapy (HR: 152.16; 95% CI: 53.57, 432.22; P < 0.001), with 10 reported early (within 45 days) in-hospital deaths secondary to multifactorial causes precluding administration of anti-platelet therapy. Other independent correlates of mortality in the PCI arm included amiodarone therapy on discharge, pre-procedural poor left ventricular ejection fraction, a history of gastrointestinal bleeding or peptic ulcer disease, PVD (HR: 2.13; 95% CI: 1.26, 3.60; P = 0.005), age, female gender (HR: 1.60; 95% CI: 1.01, 2.56; P = 0.048), and the SYNTAX score (Per increase in 10 points: HR: 1.25; 95% CI: 1.06, 1.47; P = 0.007).nnnCONCLUSIONnIndependent correlates of 4-year mortality in the SYNTAX trial were multifactorial. Lack of discharge aspirin and lack of post-procedural anti-platelet therapy were the strongest independent correlates of mortality in the CABG and the PCI arms, respectively. Peripheral vascular disease is a common independent correlate of 4-year mortality and may be a marker of the severity of baseline coronary disease and risk of future native coronary disease (and extra-cardiac disease) progression.

5-year follow-up of coronary revascularization in diabetic patients with multivessel coronary artery disease: Insights from ARTS (Arterial revascularization therapy study)-II and ARTS-I trials

OBJECTIVESnWe compared the 5-year outcomes of diabetic patients with multivessel disease treated with sirolimus-eluting stents (SES), bare-metal stents (BMS), and coronary artery bypass graft surgery (CABG) enrolled in the ARTS (Arterial Revascularization Therapy Study) I and II studies.nnnBACKGROUNDnDiabetes is an established risk factor for major adverse cardiac events after revascularization. Recent trials suggest that revascularization with drug-eluting stents has equivalent safety to CABG up to 2 years.nnnMETHODSnThe ARTS I and II studies included 367 diabetic patients (SES: 159, CABG: 96, and BMS: 112) compared with respect to 5-year clinical outcomes.nnnRESULTSnThe rate of major adverse cardiovascular and cerebrovascular events was significantly higher in patients treated with BMS (BMS 53.6% vs. CABG 23.4% vs. SES 40.5%; log-rank, p < 0.01 for SES vs. BMS and SES vs. CABG). There was no significant difference in mortality among all 3 groups. There was, however, a statistically significant difference in the myocardial infarction rate between BMS and CABG arms (BMS 11.0%, CABG 5.2%, SES 4.8%, p = 0.04 for SES vs. BMS and p = 0.76 for SES vs. CABG). The rate of repeat revascularization was significantly lower in patients treated with CABG compared with SES (SES 33.2% vs. CABG 10.7%, p < 0.001). Revascularization rate of patients treated with SES at 5 years approached that of patients treated with BMS although remained significantly lower. This catch-up phenomenon was not apparent in the nondiabetic population.nnnCONCLUSIONSnAt 5-year follow-up, CABG has comparable safety and superior efficacy compared with BMS and SES in the treatment of diabetic patients with multivessel disease.

Assisted circulation using the TandemHeart® during very high-risk PCI of the unprotected left main coronary artery in patients declined for CABG†

Objectives: In a single center experience, we retrospectively evaluated the short‐term safety and efficacy of the TandemHeart® percutaneous transseptal left ventricular assist (PTVA®) system to deliver extracorporeal circulatory support during catheter based treatment of the unprotected left main coronary artery (ULMCA). Background: Percutaneous Coronary Intervention (PCI) of the ULMCA usually has been restricted to patients who are hemodynamically unstable or ineligible for coronary artery bypass grafting (CABG). High‐risk patients for CABG should be considered at increased risk for PCI as well. In these patients the TandemHeart PTVA System (p‐LVAD) may provide a valuable safeguard to reduce procedural risks. Methods and Results: Between July 2002 and May 2008 the TandemHeart was used in 9 very high risk patients (Logistic Euro score: 13.64 (7.46–29.67); Syntax score:43 (41–50); Mayo Clinic Risk score (MCRS) 7 (6–8); age: median 65 (range 55–71) undergoing elective PCI for the novo lesions on the ULMCA. All patients were declined for CABG by a heart team. A ‘‘true’’ percutaneous insertion technique was used in all patients, technical success rate was 100%. The median (range) time for implementation of circulatory support was 27 min (24–30). A median (range) pump flow up to 4.36 (3.40–5.54) L/min was achieved with significant reduction of left ventricular filling pressures, pulmonary capillary wedge pressure and a small increase of systemic arterial pressures. Median (range) duration of support was 93 min (50.4–102). Successful weaning was achieved in all patients. There was no in hospital death, survival at 6 months was (89%), whereas vascular access site complications were seen in 4 patients (44.4%). Conclusions: In very high risk PCI, assisted circulation using the TandemHeart‐PTVA provides effective, total left ventricular support and may contribute to a reduced procedural risk and improved survival. The rate of device related cardiac and vascular complications was acceptable.