Author + information
- Received June 5, 2013
- Revision received November 14, 2013
- Accepted November 22, 2013
- Published online May 1, 2014.
- Ravi V. Shah, MD∗,†,
- Bobak Heydari, MD, MPH∗,
- Otavio Coelho-Filho, MD, MPH‡,
- Siddique A. Abbasi, MD∗,
- Jiazhuo H. Feng, BS∗,
- Tomas G. Neilan, MD∗,†,
- Sanjeev Francis, MD†,
- Ron Blankstein, MD∗,
- Michael Steigner, MD∗,
- Michael Jerosch-Herold, PhD∗ and
- Raymond Y. Kwong, MD, MPH∗∗ ()
- ∗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
- ‡Cardiology Division, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- ↵∗Reprint requests and correspondence:
Dr. Raymond Y. Kwong, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115.
Objectives This study sought to determine feasibility and prognostic performance of stress cardiac magnetic resonance (CMR) in obese patients (body mass index [BMI] ≥30 kg/m2).
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/m2 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/m2, 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.
Dr. Shah is supported by an American Heart Association Post-Doctoral Fellowship Award (11POST000002) and a training grant from the Heart Failure National Institutes of Health Clinical Research Network (U01-HL084877). Dr. Heydari is supported by a Clinical Fellowship Award from the Alberta Heritage Foundation for Medical Research. Dr. Kwong is supported by National Institutes of Health grant RO1-HL091157. Dr. Kwong receives research support from Astellas Pharma US. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Shah and Heydari contributed equally to this work.
- Received June 5, 2013.
- Revision received November 14, 2013.
- Accepted November 22, 2013.
- American College of Cardiology Foundation