Trials of Special Relevance From TCT 2020

Introduction
Every major clinical meeting provides significant information for the advancement of patient care, improved understanding of mechanisms of disease, as well as evolving studies that support future exploration. In the interest of assuring that the cardiology community has access to relevant studies with important clinical application, the ACC.org Editorial Board highlights certain trials for special recognition. What follows are those selected studies from Transcatheter Cardiovascular Therapeutics 2020 focusing on relevance for the practicing physician. We look forward to your response to this new format.

PROSPECT ABSORB (Percutaneous Coronary Intervention for Vulnerable Coronary Atherosclerotic Plaque)

The principle objective of the PROSPECT ABSORB randomized pilot study was to determine whether prophylactic percutaneous coronary intervention (PCI) of a vulnerable, non-obstructive, non-flow limiting lesion using a bioabsorbable scaffold (BVS) plus guideline-directed medical therapy (GDMT) would result in larger minimal lumen area compared to GDMT alone.  Study findings show that at 25-month angiographic follow-up, treatment with BVS did indeed result in increased luminal dimensions compared to GDMT alone. Authors hypothesize that presence of BVS may provide stabilization of vulnerable plaque although current trial was not powered to study clinical end points.  Based on their pilot study findings, safety and clinical efficacy of BVS to treat vulnerable, non-obstructive, non-flow limiting plaque would need to be tested in a large, randomized trial.1

Reliable identification and management of vulnerable coronary plaques remains controversial.  In current practice, PCI of non-acute, non-flow limiting lesions is not recommended and GDMT for secondary prevention should be instituted.  The current findings lay the groundwork for testing the hypothesis of prophylactic PCI for vulnerable plaque.  This approach, if found to be safe and clinically efficacious, stands to dramatically change the current management of coronary artery disease.      

COMPARE CRUSH (Comparison of Pre-Hospital Crushed vs. Uncrushed Prasugrel Tablets in Patients With STEMI Undergoing Primary Percutaneous Coronary Intervention)

In the COMPARE CRUSH trial, 727 patients with ST-segment elevation myocardial infarction (STEMI) were randomized to crushed or intact prasugrel tablets, administered in-ambulance prior to primary PCI.  The groups did not differ significantly with regard to either of the independent primary endpoints: TIMI 3 flow in the infarct-related artery at coronary angiography (31.0% in the crushed prasugrel group vs. 32.7% in the intact prasugrel group; p = 0.64) or complete ST-segment resolution at 1 hour post-PCI (59.9% in the crushed prasugrel group vs. 57.3% in the intact prasugrel group; p = 0.55).  Platelet reactivity, assessed from blood samples acquired at the beginning of PCI, was lower in the crushed prasugrel group (median platelet reactivity units 192 vs. 227; p < 0.01).2

In acute myocardial infarction, high platelet reactivity correlates with extent of myocardial damage.  Early platelet inhibition is protective against complications of PCI, including in-stent thrombosis.  However, in this trial, administration of crushed prasugrel tablets resulted in reduced in vitro platelet activity but did not improve short-term clinical outcomes.  This study was conducted in the Netherlands, with a largely Caucasian population, and time from study treatment to PCI was relatively short (median 57 minutes), so the results may not be generalizable to all clinical settings.  Further study is needed to determine whether early administration of the intravenous P2Y12 inhibitor cangrelor can improve clinical outcomes in patients undergoing primary PCI for STEMI.

ULTIMATE (Intravascular Ultrasound Versus Angiography-Guided Drug-Eluting Stent Implantation)

This study explored the difference in target vessel failure (TVF) 3 years after intravascular ultrasound (IVUS) guidance versus angiography guidance for all-comers undergoing second-generation drug-eluting stent (DES) implantation. IVUS-guided DES implantation was associated with significantly lower rates of TVF and stent thrombosis during a 3-year follow-up in all-comers, particularly for patients who underwent the IVUS-defined optimal procedure, compared with those with angiography guidance. Multiple randomized trials now support the use of IVUS guidance in optimizing coronary stent implantation as a mechanism to reduce adverse cardiac events. Additional larger prospective studies are indicated to identify the most optimal IVUS-defined criteria and how to achieve these IVUS criteria for the best outcomes.3

A total of 1,448 all-comers undergoing DES implantation who were randomly assigned to either IVUS guidance or angiography guidance in the ULTIMATE trial was followed for 3 years. The primary endpoint was the risk of TVF at 3 years. The safety endpoint was definite or probable stent thrombosis. At 3 years, TVF occurred in 47 (6.6%) patients in the IVUS-guided group and in 76 (10.7%) patients in the angiography-guided group (p = 0.01), mainly driven by the decrease in clinically driven target vessel revascularization (4.5% vs. 6.9%, p = 0.05). The definite or probable stent thrombosis rate was 0.1% in the IVUS-guided group and 1.1% in the angiography-guided group (p = 0.02). Notably, the IVUS-defined optimal procedure was associated with a significant reduction in 3-year TVF relative to that with the suboptimal procedure.

References

  1. Stone GW, Maehara A, Ali ZA, et al. Percutaneous Coronary Intervention for Vulnerable Coronary Atherosclerotic Plaque. J Am Coll Cardiol 2020;Oct 14:[Epub ahead of print].
  2. Vlachojannis G, Wilschut JM, Vogel R, et al. Effect of pre-hospital crushed prasugrel tablets in patients with STEMI planned for primary percutaneous coronary intervention: the randomized COMPARE CRUSH trial. Circulation 2020;Oct 14:[Epub ahead of print].
  3. Gao XF, Ge Z, Kong XQ, et al. Three-Year Outcomes of the ULTIMATE Trial Comparing Intravascular Ultrasound Versus Angiography-Guided Drug-Eluting Stent Implantation. JACC Cardiovasc Interv 2020;Oct 15:[Epub ahead of print].

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: TCT20, Transcatheter Cardiovascular Therapeutics, Coronary Artery Disease, Coronary Angiography, Drug-Eluting Stents, Percutaneous Coronary Intervention, ST Elevation Myocardial Infarction, Plaque, Atherosclerotic, Prospective Studies, Secondary Prevention, Pilot Projects, Follow-Up Studies, Absorbable Implants


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