title: Absolute and relative changes in carotid intima-media thickness and atherosclerotic plaques during long-term antihypertensive treatment: further results of the European Lacidipine Study on Atherosclerosis (ELSA).
abstract: BACKGROUND
  In ELSA, a randomized, double-blind trial in 2334 hypertensives, 4-year antihypertensive treatment with lacidipine slowed down progression of carotid atherosclerosis significantly more than atenolol treatment. To avoid bias, the primary outcome was measured blindly at study-end on a randomized sequence of scans, but measurements were limited to the four far walls of common carotids and bifurcations (CBMmax) and to one of each couple of duplicate scans recorded yearly.
  
  
  OBJECTIVE
  Secondary outcomes included measurements made on all duplicate scans of both near and far walls, not only of common carotids and bifurcations, but also of internal carotids (12 walls). These measurements were made blindly during the 4-year study, shortly after recording. To avoid possible readers' drift or bias, 250 duplicate baseline scans were re-read at yearly intervals (longitudinal on-line quality control) and a correction factor calculated.
  
  
  RESULTS
  Measurements during the 4-year study showed a trend toward decreased values, with the lacidipine effect significantly greater than the atenolol one. A trend toward lower values was also observed in the longitudinal quality control of baseline scans. After applying a correction factor calculated from this longitudinal control, all measurements no longer decreased with time, but significantly increased, with progression being significantly smaller in lacidipine than in atenolol patients. Corrected values were quite similar to those calculated on measurements carried out at study-end.
  
  
  CONCLUSIONS
  The relative benefit of lacidipine over atenolol could be measured precisely by reading scans either during the study or at study-end. However, absolute treatment-related changes (progression versus regression) cannot safely be judged by readings made during a long-term study, unless a longitudinal quality control of readings is performed.
authors.affiliation: Centro Interuniversitario di Fisiologia Clinica e lpertensione, University of Milan, Milan, Italy. alberto.zanxhetti@unimi.it
authors.forename: Alberto
authors.initials: A
authors.lastname: Zanchetti
authors.forename: M Gene
authors.initials: MG
authors.lastname: Bond
authors.forename: Michael
authors.initials: M
authors.lastname: Hennig
authors.forename: Rong
authors.initials: R
authors.lastname: Tang
authors.forename: Regina
authors.initials: R
authors.lastname: Hollweck
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mancia
authors.forename: Lothar
authors.initials: L
authors.lastname: Eckes
authors.forename: Dino
authors.initials: D
authors.lastname: Micheli
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001262:Atenolol / Q000627:therapeutic use*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000187:drug effects*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000187:drug effects*; D004095:Dihydropyridines / Q000627:therapeutic use*; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology*; D014463:Ultrasonography
chemical_list: D000959:Antihypertensive Agents; D004095:Dihydropyridines; C060285:lacidipine; D001262:Atenolol