title: The Left Main Bifurcation Angle and Changes Throughout the Cardiac Cycle: Quantitative Implications for Left Main Bifurcation Stenting and Stents.
abstract: OBJECTIVE
  The objective of this study was to quantify the left main (LM) bifurcation angles and their changes throughout the cardiac cycle.
  
  
  BACKGROUND
  LM stenting is an accepted alternative to coronary artery bypass grafting. However, the LM bifurcation has great anatomic variability. Three-dimensional angles and their cyclic changes are important for coronary stenting.
  
  
  METHODS
  Patients undergoing coronary computed tomography angiography (CCTA) for chest pain were scanned and analyzed in three-dimensional views for left main-left anterior descending (LM-LAD), left main-left circumflex (LM-LCX), and left anterior descending-left circumflex (LAD-LCX) angles and their cyclic changes. Calculations and assessment of angles, angular variability, and how these angles change throughout the cardiac cycle were analyzed.
  
  
  RESULTS
  Forty-four patient scans were analyzed. The median end-diastolic LM-LCX angle was 130° and the LAD-LCX was 74°. Median end-systolic angle for the LM-LCX was 133°, and LAD-LCX was 69°. Large differences were found across all three absolute angles (LM-LCX, LAD-LCX, LM-LAD). Marked variability also occurred in how these angles changed throughout the cardiac cycle.
  
  
  CONCLUSIONS
  LM bifurcation geometry in patients shows marked absolute angle variability, as does diastolic-systolic angle movement. LM bifurcation stents should accommodate wide interpatient bifurcation angles at rest for both the LM-LAD and LM-LCX angles.
authors.forename: Chauncy B
authors.initials: CB
authors.lastname: Handran
authors.forename: Ross F
authors.initials: RF
authors.lastname: Garberich
authors.forename: John R
authors.initials: JR
authors.lastname: Lesser
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Henry
authors.forename: Michael
authors.initials: M
authors.lastname: Gilmore
authors.affiliation: Minneapolis Heart Institute Foundation at Abbott Northwestern Hospital, 920 East 28th Street, Suite 620, Minneapolis, MN 55407 USA. robschwartzmd@gmail.com.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Schwartz
mesh_terms: D000368:Aged; D000790:Angiocardiography / Q000379:methods; D002637:Chest Pain / Q000175:diagnosis / Q000000981:diagnostic imaging; D000072226:Computed Tomography Angiography / Q000379:methods; D017023:Coronary Angiography / Q000379:methods; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results