title: Vasodilator stress perfusion CMR imaging is feasible and prognostic in obese patients.
abstract: OBJECTIVE
  This study sought to determine feasibility and prognostic performance of stress cardiac magnetic resonance (CMR) in obese patients (body mass index [BMI] ≥30 kg/m(2)).
  
  
  BACKGROUND
  Current stress imaging methods remain limited in obese patients. Given the impact of the obesity epidemic on cardiovascular disease, alternative methods to effectively risk stratify obese patients are needed.
  
  
  METHODS
  Consecutive patients with a BMI ≥30 kg/m(2) referred for vasodilating stress CMR were followed for major adverse cardiovascular events (MACE), defined as cardiac death or nonfatal myocardial infarction. Univariable and multivariable Cox regressions for MACE were performed to determine the prognostic association of inducible ischemia or late gadolinium enhancement (LGE) by CMR beyond traditional clinical risk indexes.
  
  
  RESULTS
  Of 285 obese patients, 272 (95%) completed the CMR protocol, and among these, 255 (94%) achieved diagnostic imaging quality. Mean BMI was 35.4 ± 4.8 kg/m(2), with a maximum weight of 200 kg. Reasons for failure to complete CMR included claustrophobia (n = 4), intolerance to stress agent (n = 4), poor gating (n = 4), and declining participation (n = 1). Sedation was required in 19 patients (7%; 2 patients with intravenous sedation). Sixteen patients required scanning by a 70-cm-bore system (6%). Patients without inducible ischemia or LGE experienced a substantially lower annual rate of MACE (0.3% vs. 6.3% for those with ischemia and 6.7% for those with ischemia and LGE). Median follow-up of the cohort was 2.1 years. In a multivariable stepwise Cox regression including clinical characteristics and CMR indexes, inducible ischemia (hazard ratio 7.5; 95% confidence interval: 2.0 to 28.0; p = 0.002) remained independently associated with MACE. When patients with early coronary revascularization (within 90 days of CMR) were censored on the day of revascularization, both presence of inducible ischemia and ischemia extent per segment maintained a strong association with MACE.
  
  
  CONCLUSIONS
  Stress CMR is feasible and effective in prognosticating obese patients, with a very low negative event rate in patients without ischemia or infarction.
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Ravi V
authors.initials: RV
authors.lastname: Shah
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Bobak
authors.initials: B
authors.lastname: Heydari
authors.affiliation: Cardiology Division, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Otavio
authors.initials: O
authors.lastname: Coelho-Filho
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Siddique A
authors.initials: SA
authors.lastname: Abbasi
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Jiazhuo H
authors.initials: JH
authors.lastname: Feng
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Tomas G
authors.initials: TG
authors.lastname: Neilan
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Francis
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Ron
authors.initials: R
authors.lastname: Blankstein
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Michael
authors.initials: M
authors.lastname: Steigner
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Michael
authors.initials: M
authors.lastname: Jerosch-Herold
authors.affiliation: Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: rykwong@partners.org.
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Kwong
mesh_terms: D015992:Body Mass Index; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D009765:Obesity / Q000150:complications*; D011379:Prognosis; D012189:Retrospective Studies; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents
keywords: cardiac magnetic resonance; obesity; stress testing
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