Analysis of Human Coronary Aspirate (AHCA)

• Characterisation of particular and soluble substances released during stenting into coronary aspirate and its vasoconstrictor potential. [ Time Frame: up to two years ] [ Designated as safety issue: No ]
  • biochemical characterisation: (quantification (as amount or concentration) of vasoconstrictive substances; cell fragments, proteins and lipids within the aspirat via HPLC, MS, or EIA Kits)
  • in vitro vasoconstriction, coronary microcirculation and cardiac contraction by aspirate (vasoconstriction detected as response of isolated arteries to aspirate normalized to that by KCl in a myograph; coronary microcirculation detected as coronary flow and cardiac contraction as left ventricular pressure within in the in vitro langendorff-heart modell)
  
  

• Correlation of characteristics of soluble and particular substances within aspirate to characteristics of coronary lesion and/or patients underlying disease [ Time Frame: up to three years ] [ Designated as safety issue: No ]
  e.g.: concentration of vasoconstrictors to plaque composition; concentration of vasoconstrictors to patient underlying disease; amount of particular debris to plaque composition; amount of particular debris to patient underlying disease
  
  

Patients

• Symptomatic patients with a significant diameter stenosis (>75%) 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 ultrasound analyses before stent implantation (Eagle-EyeTM 20 MHz catheter and R-100 pullback device, Volcano Corporation, Rancho Cordova, CA, USA). Determination of plaque composition with virtual histology using a customized software (pcVHTM2.1, Volcano Corp.).

Interventional procedure

Distal balloon occlusion devices:

• TriAktiv SVG/3.5-FX-catheter; Kensey Nash, Exton, USA or
• GuardWireR 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 Heparine- 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 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.