Author + information
- Received January 13, 2019
- Accepted February 6, 2019
- Published online May 27, 2019.
- Juarez R. Braga, MDa,
- Peter C. Austin, PhDa,b,
- Heather J. Ross, MD, MHScc,d,
- Jack V. Tu, MD, PhDa,b,e and
- Douglas S. Lee, MD, PhDa,b,c,d,∗ ()
- aInstitute for Health Policy, Management, and Evaluation, University of Toronto, Toronto, Canada
- bInstitute for Clinical Evaluative Sciences (ICES), Toronto, Canada
- cPeter Munk Cardiac Centre, University Health Network, Toronto, Canada
- dTed Rogers Centre for Heart Research, Toronto, Canada
- eSchulich Heart Centre, Sunnybrook Health Sciences Centre, Toronto, Canada
- ↵∗Address for correspondence:
Dr. Douglas S. Lee, ICES and University Health Network, Division of Cardiology, 2075 Bayview Avenue, G-wing, Toronto, Ontario M4N 3M5, Canada.
Objectives This study sought to examine the prognostic significance of nonobstructive coronary artery disease (CAD) in patients with heart failure (HF), as a distinct category apart from those with normal coronary arteries.
Background Individuals with HF are often dichotomized into ischemic versus nonischemic categories according to the underlying etiology. This binary classification creates a heterogeneous group, combining individuals with nonobstructive CAD with those with normal coronary arteries under the nonischemic label.
Methods A cohort of individuals with HF and reduced ejection fraction undergoing invasive coronary angiography was examined and linked to administrative databases for outcomes evaluation. Patients were divided into those with normal coronary arteries, nonobstructive disease, and obstructive disease. The primary outcome was the composite of cardiovascular death, nonfatal acute myocardial infarction, nonfatal stroke, or HF hospitalization.
Results Of 12,814 individuals, 2,656 (20.7%) had normal coronary arteries, 2,254 (17.6%) had nonobstructive CAD, and 7,904 (61.7%) had obstructive CAD. The risk of the primary outcome was increased in the nonobstructive group (hazard ratio [HR]: 1.17; 95% confidence interval [CI]: 1.04 to 1.32; p = 0.01) relative to those with normal coronary arteries. Nonobstructive CAD was associated with an increased hazard of cardiovascular death (HR: 1.82; 95% CI: 1.27 to 2.62; p = 0.001) and death of any cause (HR: 1.18; 95% CI: 1.05 to 1.33; p = 0.005). There were no significant differences in the rate of acute myocardial infarction, stroke, or HF hospitalization.
Conclusions Among HF patients with reduced ejection fraction, the presence of nonobstructive CAD was independently associated with an increased hazard of the primary composite outcome and death of any cause.
- coronary angiography
- coronary artery disease
- heart failure
- myocardial infarction
This study was supported by a Foundation Grant from the Canadian Institutes of Health Research (grant # FDN 148446) and the Ted Rogers Centre for Heart Research. ICES is supported in part by a grant from the Ontario Ministry of Health and Long-Term Care. Dr. Lee is supported by a mid-career investigator award from the Heart and Stroke Foundation and the Ted Rogers Chair in Heart Function Outcomes, a joint Hospital-University Chair of the University Health Network and the University of Toronto. Dr. Austin is supported by a Mid-Career Investigator Award from the Heart and Stroke Foundation (Ontario Office). The late Dr. Tu was supported by a Tier 1 Canada research chair in Health Services Research and an Eaton Scholar Award from the University of Toronto Department of Medicine. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. The opinions, results, and conclusions are those of the authors, and no endorsement by the Ministry of Health and Long-Term Care or by ICES is intended or should be inferred. Parts of this material are founded on data and information compiled and provided by the Canadian Institute for Health Information. However, the analyses, conclusions, opinions, and statements expressed herein are those of the author and not necessarily those of Canadian Institute for Health Information. The authors acknowledge that the clinical registry data used in this publication is from participating hospitals through the CorHealth Ontario Cardiac Registry, which serves as an advisory body to the Minister of Health and Long-Term Care (MOHLTC), is funded by the MOHLTC, and is dedicated to improving the quality, efficiency, access and equity in the delivery of the continuum of adult cardiac services in Ontario, Canada.
- Received January 13, 2019.
- Accepted February 6, 2019.
- 2019 The Authors