title: Restoration of flow-dependent coronary dilation by ACE inhibition improves papaverine-induced maximal coronary blood flow in hypertensive patients: demonstration that large epicardial coronary arteries are more than conductance vessels.
abstract: Restoration of flow-dependent coronary artery dilation by angiotensin-converting enzyme inhibition (ACEI) has been demonstrated in patients with hypertension. The aim of the present study was to evaluate whether dilation of conductance coronary arteries may alter maximal coronary blood flow (CBFmax) and minimal coronary resistance (CRmin) in hypertensive patients with reversible impairment of flow-dependent coronary artery dilation. Thirteen hypertensive patients with angiographically normal coronary arteries and no other risk factors were studied. Cross-sectional areas (CSAs) of proximal and distal left anterior descending (LAD) coronary arteries were determined by quantitative angiography. Coronary flow velocity was recorded in the distal LAD with an intracoronary Doppler catheter. Estimates of coronary blood flow and resistance were calculated at rest and during maximal increase in blood flow induced by papaverine injected in the midportion of the LAD, both before and after ACEI. Flow-dependent dilation of the proximal LAD, abolished before ACEI, was restored after (26.7 +/- 11.2%; p < 0.001). The increase in CSA of the distal LAD exposed to papaverine was significantly higher after ACEI than before (from 33.4 +/- 20.5% to 51.5 +/- 23.4%; p < 0.001). After restoration of proximal LAD flow-dependent dilation, CBFmax was increased by +21.0 +/- 10.3% (p < 0.001), and CRmin was reduced by 19.3 +/- 9.5% (p < 0.001). Thus, dilation of epicardial coronary arteries participates substantially in the coronary resistance in hypertensive patients. Restoration of flow-dependent coronary artery dilation by ACEI may improve the ability of coronary circulation to deliver its maximal myocardial blood flow in hypertensive patients.
authors.affiliation: Service de Physiologie et d'Explorations Fonctionnelles, Hôpital Louis Mourier, CHU Xavier Bichat, Colombes, France. isabelle.antony@lmr.ap-hop-paris.fr
authors.forename: I
authors.initials: I
authors.lastname: Antony
authors.forename: D
authors.initials: D
authors.lastname: Chemla
authors.forename: G
authors.initials: G
authors.lastname: Lerebours
authors.forename: A
authors.initials: A
authors.lastname: Nitenberg
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D017023:Coronary Angiography / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007211:Indoles / Q000494:pharmacology / Q000627:therapeutic use*; D010208:Papaverine / Q000494:pharmacology / Q000627:therapeutic use*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007211:Indoles; D014665:Vasodilator Agents; C053500:perindoprilat; D010208:Papaverine