Double Kissing Crush Stenting - DKCRUSH-VI

Description:

The current trial sought to compare outcomes of fractional flow reserve (FFR)-guided and angiography-guided provisional side branch stenting for true coronary bifurcation lesions.

Hypothesis:

A FFR-guided strategy would be superior to an angiography-guided strategy for provisional side branch stenting in true bifurcation lesions.

Study Design

  • Randomized
  • Parallel

Patient Populations:

  • Medina 1,1,1/0,1,1 bifurcation lesions
  • Side branch ≥2.5 mm in diameter
  • Lesion length in each branch could be covered by two drug-eluting stents

    Number of enrollees: 320
    Duration of follow-up: 1 year

Exclusions:

  • Medina 1,1,1/0,1,1 bifurcation lesions
  • Side branch ≥2.5 mm in diameter
  • Lesion length in each branch could be covered by two drug-eluting stents
  • Heavy calcification proximal to or within the target lesion
  • Previous CABG or PCI for the target vessel <6 m
  • Planned surgical procedure during the first 6 months after enrollment
  • Stroke within 6 months
  • Contraindication or suspected intolerance to any study drug
  • Liver dysfunction, pregnancy, expected lifespan of <1 year

Primary Endpoints:

  • MACE at 12 months

Secondary Endpoints:

  • Cardiac death
  • MI: defined as creatine kinase-myocardial band greater than threefold the 99% upper limit of normal
  • TLR, coronary artery bypass grafting (CABG), target vessel revascularization
  • Restenosis
  • Stent thrombosis

Drug/Procedures Used:

Side branch stenting was performed for TIMI flow <3, ostial side branch stenosis >70%, or > type A dissection after main vessel stenting in the angiography alone arm, or for side branch FFR <0.8 in the FFR arm.

Principal Findings:

A total of 320 patients were randomized, 160 to FFR and 160 to angiography alone. Baseline characteristics were fairly similar between the two arms. Approximately 28% had diabetes. A true Medina 1,1,1 lesion was observed in 85% of the patients; 3% of side branch lesions were chronically occluded at baseline, and a further 4% had TIMI flow <3 at baseline. The median lesion length and reference vessel diameter (RVD) in the main branch were 31 mm and 2.93 mm, respectively. The median lesion length and RVD in the side branch were 12 mm and 2.25 mm, respectively.

Following stenting of the main branch, side branch stenting was pursued in 38.1% of patients in the angiography alone arm, with successful percutaneous coronary intervention (PCI) in 84% of these. In the FFR arm, FFR was successfully measured in 90.6%, and was <0.8 in 52% of the lesions. In these patients, kissing balloon inflations were initially performed and FFR was remeasured. This was now positive in 35% of lesions with an initial positive FFR and were stented. Overall, side branch PCI was performed in 25.9% of patients with this strategy (p = 0.01).

In-segment restenosis was higher in the distal main vessel in the angiography alone arm (9.2% vs. 1.7%, p = 0.01), as was side branch vessel restenosis (11.8% vs. 21.2%, p = 0.037). However, clinical outcomes including major adverse cardiac events (MACE) (18.1% vs. 18.1%, p = 1.0), myocardial infarction (MI) (13.8% vs. 11.9%, p = 0.74), target lesion revascularization (TLR) (5.0% vs. 3.1%, p = 0.57), and stent thrombosis (1.3% vs. 0.6%) were similar between the angiography alone and FFR arms, respectively.

Interpretation:

The results of the DKCRUSH-VI trial indicate that an FFR-guided strategy results in fewer stents and less angiographic restenosis than an angiography alone strategy in true bifurcation lesions. However, clinical outcomes at 1 year were similar. Stenting of the side branch was performed using the TAP technique in this trial.

A number of earlier trials have demonstrated that provisional side branch stenting is superior to a routine side branch stenting (two-stent technique) strategy in true bifurcation lesions. Following main branch stenting, the side branch can appear altered not just due to plaque shift, but also due to a change in geometry.

There have been single-center studies showing that although they may appear angiographically severe, FFR is truly positive in <50% of lesions. The investigators extend those observations by providing further evidence through a multicenter randomized controlled trial. It thus appears reasonable to consider FFR in stenotic side branch lesions following main branch stenting to minimize the oculostenotic reflex.

References:

Presented by Dr. Shao Liang Chen at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2014), Washington, DC, September 14, 2014.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Myocardial Infarction, Thrombosis, Research Personnel, Reflex, Constriction, Pathologic, Diabetes Mellitus, Stents, Percutaneous Coronary Intervention, Transcatheter Cardiovascular Therapeutics


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