This article is more than 5 years old. Information may no longer be current.
The Take Home: TCT
Click Here to Manage Email Alerts
Source: The Cardiovascular Research Foundation; reprinted with permission.
This past October, Transcatheter Cardiovascular Therapeutics Scientific Symposium was held in Miami for the first time in its 24 years and brought in nearly 11,800 attendees. In all, 1,750 abstracts were submitted from 52 countries and 37 US states, which reviewers narrowed down to 114 oral presentations and 796 posters for a final tally of 910 accepted abstracts.
Attending the meeting were Ajay Kirtane, MD, SM, FACC, FSCAI, and Isaac George, MD, both from the New York Presbyterian Hospital – Columbia University Medical Center, who shared with Cardiology Today’s Intervention their impressions of the late-breaking data and sessions presented during the 5-day meeting.
Ajay Kirtane, MD, SM, FACC, FSCAI
A total of nine late-breaking clinical trials were presented at TCT. These trials, as well as several other trial and registry updates presented at the meeting in various other sessions, provide clinicians with potential ways to improve on current clinical practice.
Ajay Kirtane
FAME II Cost-Effectiveness
The FAME II trial was an important clinical trial for interventional cardiology because it demonstrated, in a randomized trial, that up-front PCI of fractional flow reserve-positive coronary artery lesions was associated with a reduction in unplanned hospitalization for urgent revascularization compared with medical therapy (leaving the lesion without PCI) alone. In a cost-effectiveness analysis presented at TCT, the FAME II investigators demonstrated that although up-front PCI of all these lesions was more expensive than medical therapy alone, the cost-effectiveness ratios of a PCI-based strategy did appear acceptable on a societal scale because patients had improved quality of life without experiencing adverse events (such as excess MI).
MASTER
The MASTER randomized trial examined the use of a mesh-covered bare-metal stent (MGuard, InspireMD), currently approved for use outside the United States and designed to trap thrombotic debris behind the mesh in order to prevent distal embolization, among patients (n=433) undergoing primary PCI for STEMI. In the multicenter trial, use of the MGuard stent was associated with improved rates of post-PCI TIMI flow as well as ST-segment resolution, a marker of myocardial perfusion. These data set the stage for a larger US-based trial that should begin enrollment soon.
ISAR-LEFT MAIN 2 and XIMA
These two trials examined safety and efficacy of current-generation drug-eluting stents in patient/lesion subsets extending beyond routine clinical practice. ISAR-LEFT MAIN included 650 patients with left main disease randomly assigned to PCI with either the Resolute zotarolimus-eluting stent (Medtronic) or the Xience V everolimus-eluting stent (Abbott Vascular). In this trial, both stents performed similarly, with very low rates of stent thrombosis in both groups (0.6% definite stent thrombosis for both).
The XIMA trial examined the use of the Xience V stent compared with a BMS for elderly patients older than 80 years. This trial aimed to determine whether the anti-restenotic advantages afforded by DES would be counterbalanced by increased bleeding in a vulnerable population. Despite missing the primary endpoint of the trial (MACE: BMS, 18.7% vs. DES, 14.5%; P=.092), there were no differences in bleeding rates between groups, with a modest decrease in target lesion revascularization (7% vs. 2%; P<.001), suggesting that the use of DES in appropriately selected octogenarians is effective and safe.
RESPECT and PC Trial
These trials were two of the most hotly anticipated trials at TCT 2012, both testing whether percutaneous patent foramen ovale closure in patients with cryptogenic stroke would be superior to medical therapy in the prevention of recurrent stroke events. Both trials missed their primary endpoints, in part due to the very low rate of recurrent stroke in the patient population studied (1.6% vs. 3% at 2 years in RESPECT). However, PFO closure was very well tolerated in both studies with an extremely low rate of complications. Thus, further study of the utility of targeting PFO closure to subsets of patients at the highest risk (or those unwilling to take more potent antithrombotic therapies) will be required before PFO closure in the cryptogenic stroke population becomes more widely accepted.
POSEIDON
The randomized POSEIDON trial aimed to demonstrate whether strategy of volume repletion titrated to an individual patient’s LV end diastolic pressure (LVEDP) could reduce the incidence of contrast-induced nephrotoxicity (CIN) during cardiac catheterization. Patients at high risk for CIN had LVEDP measured prior to angiography, and the rate of hydration was increased or decreased accordingly in the experimental arm, or managed by standard practice in the control arm. Overall, the LVEDP-based titration strategy was associated with a significant reduction in the rate of CIN in these high-risk patients. This strategy of avoiding one of the serious complications of cardiac catheterization should be relatively easy to implement in most cardiac cath labs.
ISAR-DESIRE 3
The optimal management of DES restenosis is unclear, with a variety of approaches currently in use by treating physicians (including repeat DES, stand-alone balloon angioplasty or — if available — drug-eluting balloon angioplasty). The ISAR-DESIRE 3 study randomly assigned 402 patients with DES restenosis to either paclitaxel-eluting stent (PES) implantation, treatment with a paclitaxel-eluting balloon (PEB) or angioplasty with a standard balloon. Patients treated with either PEB or PES had lower rates of repeat restenotic events compared with standard balloon angioplasty, and the PEB performed very similarly to the PES. These data suggest that when PEB become available in the United States, they should be considered first-line for the treatment of DES restenosis.
STEMI-RADIAL
There has been a growing interest in transradial PCI in the United States, and for patients at the greatest risk for bleeding events (those with STEMI), there have been several sources of data suggesting that the use of transradial access can improve outcomes compared with femoral access. In the STEMI-RADIAL trial, 707 patients at high-volume transradial centers were randomly assigned to the radial vs. femoral approach for STEMI PCI. The transradial approach was associated with a lower rate of bleeding complications (1.4% vs. 7.2%; P<.001), with similar rates of overall MACE. These data, combined with other prior studies, suggest that — for operators who are facile in transradial intervention — the transradial approach may be the preferred approach in STEMI patients.
Disclosure: Kirtane reports no relevant financial disclosures.
Isaac George, MD
Valvular Heart Disease Summit: Part 1 – Aortic Valve Therapies
FDA approval for transfemoral transcatheter aortic valve replacement in the United States occurred in November 2011 for inoperable patients, and penetration of TAVR in the European Union has reached 25%, leading to unprecedented growth in high-volume centers.
Isaac George
At TCT, several important data updates on TAVR were presented. First, mortality from TAVR continues to drop compared with early experience for high-risk patients, according to results from the German Aortic Valve Registry (GARY) trial, SOURCE XT registry and other high-volume European registries documenting 30-day mortalities of 4.1% to 5.7% for transfemoral access, independent of device type. Persistent predictors of mortality in all studies continue to be paravalvular leak, worsened NYHA Class upon presentation and transapical access. Data from the PARTNER non-randomized transfemoral registry demonstrate progress in terms of mortality (4.9%), stroke (3.8%) and paravalvular leak (PVL; <10% moderate-severe), which represent significant advances from the early experience and importantly fail to show an effect of mild PVL on survival. Continued-access registry data for the transapical approach from the PARTNER trial were presented and showed a distinct reduction in stroke after the procedure vs. the pre-market approval trial data (6.1% vs. 12.5%), though mortality in this high-risk group remained high at 33.6% at 2 years.
Given the almost double mortality seen with transapical access compared with transfemoral access, increased interest has been shown in direct aortic access, in which the ascending aorta is accessed through a mini-sternotomy and TAVR is performed. Proposed benefits include reduced pain, quicker recovery, less pulmonary complications and fewer bleeding events.
Finally, two TAVR studies in the United States are ongoing. The PARTNER II trial continues enrollment for intermediate-risk patients, with important differences from PARTNER I being the inclusion of coronary disease and its treatment, a 29-mm size valve in addition to 23-mm and 26-mm sizes and a significantly smaller device sheath size (16F-20F) expected to drastically reduce vascular complications. The Medtronic CoreValve pivotal trial has completed enrollment and results will be upcoming. Future studies evaluating cost-effectiveness, risk-stratification, valve-in-valve and futility in TAVR will guide decision-making in the current era.
Valvular Heart Disease Summit: Part 2 – Mitral Valve Therapies
The anatomic difficulties underlying percutaneous mitral valve technology have limited successful transition from preclinical to clinical application. Currently, the only device under investigation in the United States is the MitraClip (Abbott Vascular).
Updates to the COAPT trial design were presented at TCT. The COAPT trial is a 420-patient, randomized controlled trial comparing the MitraClip with optimal medical therapy for moderate-severe, functional mitral regurgitation (MR) in patients deemed extremely high risk for surgery. This study comes on the heels of EVEREST II, in which the clip was compared with traditional mitral valve surgery and found to be safe, although less effective in reducing MR.
Updates were also presented on two percutaneous annuloplasty devices: the Carillon Mitral Contour System (Cardiac Dimensions) and the CardiAQ Valve Technologies system; both have been shown feasible for reduction of annulus size. Further study is under way.
Finally, valve-in-valve procedures via transapical access for both failed bioprosthetic valves and prior annuloplasty rings have increased in popularity, though careful planning and specialized expertise are required.
Main Arena – Structural Heart and Other Novel Technology
A number of non-TAVR advances in percutaneous structural heart disease were presented, either as part of live case demonstrations or as potential future technologies.
Select stable patients with a post-MI ventricular septal defect (VSD) may benefit from the recently released Amplatzer (St. Jude Medical) and Occlutech (Occlutech) Post-MI VSD closure devices, specifically designed to reduce radial force at the waist, yet provide adequate left and right ventricular coverage over necrotic VSD tissue. These devices range from elliptical waist sizes of 16 mm to 36 mm (larger than traditional VSD devices) and are accommodated by 10F to 14F sheaths.
Finally, the experience is growing with adult congenital patients with aortic coarctation successfully treated with stenting (bare-metal or covered) or pulmonary valve/RV conduit failure treated with transcatheter valve replacement with the Sapien (Edwards Lifesciences) and Melody (Medtronic) valves.
Surgical, Interventional and Hybrid Procedures
One of the best attended concurrent sessions at TCT was the American Association for Thoracic Surgery (AATS) Symposium for Surgical, Interventional and Hybrid Procedures, in which considerable debate was generated on the continued controversy regarding the optimal treatment for multivessel and left main disease.
Review of the recently released 5-year SYNTAX trial data revealed similar trends as in previous years, including disparity between CABG and PCI for high SYNTAX scores (>32), with death (11.4% vs. 19.2%) and composite death/cerebrovascular accident (CVA)/MI (17.1% vs. 26.1%) favoring CABG. However, for low (0-22; data shown) and intermediate scores (23-32), there was equivalence between the procedures for death (CABG, 10.1% vs. PCI, 8.9%) and death/CVA/ MI (CABG, 14.9% vs. PCI, 16.1%), but higher revascularization rates for PCI (23% vs. 16.9%).
However, several arguments were made that these trial data may not be currently applicable based on several reports of improved performance of second- and third-generation DES platforms and optimized PCI with FFR or IVUS, neither of which were reflected in SYNTAX. As such, particularly for left main CAD, the results from the EXCEL trial for PCI vs. CABG for left main disease are eagerly awaited, as primary endpoints of death, MI and stroke will be examined at 3 years in patients with unprotected left main disease.
Finally, one of the main focuses of the symposium was the hybrid approach to coronary disease. Experienced, specialized centers, such as Vanderbilt, University of Maryland, Columbia and Emory, described hybrid techniques to both coronary and valvular disease, in which open cardiac surgery for coronary or valvular disease was performed in a staged or single setting in conjunction with PCI. With the primary rationale to lower operative risk (especially in re-operative surgery) or facilitate minimally invasive surgery (for example, minimally invasive direct coronary artery bypass surgery plus PCI, or minimally invasive mitral valve repair plus PCI), creative treatment plans (shown with detailed algorithms to minimize bleeding and maintain stent patency) may improve overall operative outcomes and maximize the benefits of both interventional cardiology and cardiac surgery.
Disclosure: George reports no relevant financial disclosures.