title: Evaluation of improved coronary flow velocity reserve using transthoracic Doppler echocardiography after single LDL apheresis.
abstract: The purpose of this study was to clarify whether coronary flow velocity reserve (CFVR), evaluated by adenosine 5'-triphosphate-induced hyperemia, is improved by single low-density lipoprotein (LDL) apheresis. Lipid lowering therapy is known to improve endothelium-dependent vasodilatation in forearm or coronary resistant vessels. However, few reports have studied the effect of acute LDL reduction on CFVR.
  
  
  METHODS
  Seven patients with familial hypercholesterolemia and significant coronary stenosis except in the left anterior descending artery (LAD) were enrolled in this study. Coronary flow velocity reserve was estimated before and after LDL apheresis using transthoracic Doppler echocardiography (TTDE), which detects the flow velocity at the distal site of the LAD. Although the averaged diastolic peak velocity (ADPV) during ATP-induced hyperemia was similar before and after LDL apheresis, the ADPV at baseline decreased from 30.69 to 25.56 cm/s, resulting in an increased CFVR from 1.78 to 2.10 (P < 0.001). Plasma bradykinin and 6 keto PGF1alpha increased while fibrinogen and plasma viscosity decreased after apheresis. Single LDL apheresis improves CFVR according to TTDE analysis because of the decreasing ADPV at baseline, which is thought to be induced by epicardial coronary artery dilatation and improved microvessel function. This is the result of various factors, such as changes in plasma LDL cholesterol, bradykinin and PGI2 levels with LDL apheresis.
authors.affiliation: The 2nd Department of Internal Medicine, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Yamashita
authors.forename: Hiromi
authors.initials: H
authors.lastname: Tasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuka
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Nihei
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ozumi
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Nakashima
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D008078:Cholesterol, LDL; D003331:Coronary Vessels / Q000502:physiology*; D016238:Cytapheresis; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D008078:Cholesterol, LDL