Analysis of Human Coronary Aspirate

Human Coronary Aspirate: Characterization of Particular and Soluble Substances and the Impact on Microvascular Obstruction

During elective percutaneous coronary intervention (PCI), both proximal and distal protection devices are used. The distal occlusion protection device temporarily occludes the vessel distal to the lesion during the intervention, thereby capturing both particular debris and soluble substances released from the lesion such that they can be aspirated and prevented from reaching the coronary microcirculation. Rather than simply discarding the material which is retrieved from use of protection devices, the investigators have recently taken advantage of this situation, sampled the particulate and soluble material and subjected it to a variety of analyses with the ultimate goal to have a better insight into the respective plaque composition and to correlate it to the individual imaging and clinical data. On the basis of such information the investigators aim to better understand the pathophysiology of plaque vulnerability and to possibly predict the clinical development of the individual patient.

Patients

• Symptomatic patients with a significant stenosis (diameter stenosis >75% or significant FFR) in a native coronary vessel or a saphenous vein aortocoronary bypass graft.
• All patients are on aspirin (100 mg/day) and received 10,000 I.U. heparin intravenously.
• Coronary angiography is performed via the femoral approach.
• Full informed consent are obtained from all patients before participating in the study.

Stenosis severity/Plaque composition

• Quantification of stenosis severity was performed with the use of off-line caliper measurements (QCA-MEDIS, Leiden, NL).

• Intravascular imaging analyses before and after stent implantation to characterize plaque morphology:

  1. IVUS(Eagle-EyeTM 20 MHz catheter and R-100 pullback device, Volcano Corporation, Rancho Cordova, CA, USA)
  2. OCT (St. Jude Medical Lightlab C7 Dragonfly Imaging Catheter)
  3. NIRS (InfraReDx TVC Insight catheter)

Interventional procedure

Distal balloon occlusion devices:

• TriAktiv SVG/3.5-FX-catheter; Kensey Nash, Exton, USA or
• GuardWire Temporary Occlusion & Aspiration System; Medtronic Inc., Minneapolis, MN USA Implantation of balloon-expandable stents using balloon pressures between 14 and 18 atm and a balloon-to-vessel diameter ratio of 1:1.

Coronary arterial blood and coronary aspirate

• Coronary arterial blood is taken distal to the lesion before stent implantation and coronary aspirate blood is obtained during stent implantation (each in Heparin- or EDTA- Monovettes, SARSTEDT AG & Co, Nümbrecht, Germany).
• Ex vivo coronary aspirate blood is filtered through a mesh filter with pores of 40 μm diameter.
• Immediately centrifugation of the filtered coronary arterial and aspirate blood (800g, 10 min, 4°C).
• Particulate debris and coronary arterial and aspirate plasma are quickly frozen in liquid nitrogen and stored at -80°C until further use.

Analysis / Aim :

• Using different methods for determining severity of stenosis and plaque composition.
• Using different biochemical methods to characterize particular and soluble substances released during stenting into coronary aspirate.
• Using different bioassays to study vasoconstrictor potential of human coronary aspirate plasma and the impact. of coronary aspirate on the coronary microcirculation and on cardiac contraction.
• Correlation of ex vivo measurements with patients disease and clinical symptoms.

Inclusion Criteria:

• Symptomatic patients with a significant stenosis (diameter stenosis >75% or significant FFR) in a native coronary vessel or a saphenous vein aortocoronary bypass graft

Exclusion Criteria:

• Patients whereby a distal balloon occlusion devices is not applicable