title: Outcomes After Orbital Atherectomy of Severely Calcified Left Main Lesions: Analysis of the ORBIT II Study.
abstract: OBJECTIVE
  The ORBIT II trial reported excellent outcomes in patients with severely calcified coronary lesions treated with orbital atherectomy. Severe calcification of the left main (LM) artery represents a complex coronary lesion subset. This study evaluated the safety and efficacy of coronary orbital atherectomy to prepare severely calcified protected LM artery lesions for stent placement.
  
  
  METHODS
  The ORBIT II trial was a prospective, multicenter clinical trial that enrolled 443 patients with severely calcified coronary lesions in the United States. The major adverse cardiac event (MACE) rate through 2 years post procedure, defined by cardiac death, myocardial infarction (CK-MB >3x upper limit of normal with or without a new pathologic Q-wave) and target-vessel revascularization, was compared in the LM and non-left main (NLM) groups.
  
  
  RESULTS
  Among the 443 patients, a total of 10 underwent orbital atherectomy of protected LM artery lesions. At 2 years, there was no significant difference in the 2-year MACE rate in the LM and NLM groups (30.0% vs 19.1%, respectively; P=.36). Cardiac death was low in both groups (0% vs 4.4%, respectively; P=.99). Myocardial infarction occurred within 30 days in both groups (10.0% vs 9.7%, respectively; P=.99). Severe dissection, perforation, persistent slow flow, and persistent no reflow did not occur in the LM group. Abrupt closure occurred in 1 patient in the LM group.
  
  
  CONCLUSIONS
  Orbital atherectomy for patients with heavily calcified LM coronary artery lesions is safe and feasible. Further studies are needed to assess the safety and efficacy of orbital atherectomy in patients with severely calcified LM artery lesions.
authors.affiliation: UCLA Medical Center, 100 Medical Plaza, Suite 630, Los Angeles, CA 90095 USA. mslee@mednet.ucla.edu.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Lee
authors.forename: Evan
authors.initials: E
authors.lastname: Shlofmitz
authors.forename: Richard
authors.initials: R
authors.lastname: Shlofmitz
authors.forename: Sheila
authors.initials: S
authors.lastname: Sahni
authors.forename: Brad
authors.initials: B
authors.lastname: Martinsen
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Chambers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017225:Atherectomy, Coronary / Q000379:methods* / Q000401:mortality; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000601:surgery*; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation* / Q000379:methods; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D015607:Stents; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States