title: Cardiac magnetic resonance imaging myocardial perfusion reserve index assessment in women with microvascular coronary dysfunction and reference controls.
abstract: OBJECTIVE
  We sought to comparatively assess cardiac magnetic resonance imaging (CMRI) myocardial perfusion reserve index (MPRI) in women with confirmed microvascular coronary dysfunction (MCD) cases and reference control women.
  
  
  BACKGROUND
  Women with signs or symptoms of myocardial ischemia in the absence of obstructive coronary artery disease (CAD) frequently have MCD which carries an adverse prognosis. Diagnosis involves invasive coronary reactivity testing (CRT). Adenosine CMRI is a non-invasive test that may be useful for the detection of MCD.
  
  
  METHODS
  Fifty-three women with MCD confirmed by CRT and 12 age- and estrogen-use matched reference controls underwent adenosine CMRI. CMRI was assessed for MPRI, calculated using the ratio of myocardial blood flow at hyperemia/rest for the whole myocardium and separately for the 16 segments as defined by the American Heart Association. Statistical analysis was performed using repeated measures ANOVA models.
  
  
  RESULTS
  Compared to reference controls, MCD cases had lower MPRI values globally and in subendocardial and subepicardial regions (1.63±0.39 vs. 1.98±0.38, P=0.007, 1.51±0.35 vs. 1.84±0.34, P=0.0045, 1.68±0.38 vs. 2.04±0.41, P=0.005, respectively). A perfusion gradient across the myocardium with lower MPRI in the subendocardium compared to the subepicardium was observed for both groups.
  
  
  CONCLUSIONS
  Women with MCD have lower MPRI measured by perfusion CMRI compared to reference controls. CMRI may be a useful diagnostic modality for MCD. Prospective validation of a diagnostic threshold for MPRI in patients with MCD is needed.
authors.affiliation: Barbra Streisand Women's Heart Center Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Chrisandra L
authors.initials: CL
authors.lastname: Shufelt
authors.forename: Louise E J
authors.initials: LE
authors.lastname: Thomson
authors.forename: Pavel
authors.initials: P
authors.lastname: Goykhman
authors.forename: Megha
authors.initials: M
authors.lastname: Agarwal
authors.forename: Puja K
authors.initials: PK
authors.lastname: Mehta
authors.forename: Tara
authors.initials: T
authors.lastname: Sedlak
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Edward
authors.initials: E
authors.lastname: Gill
authors.forename: Bruce
authors.initials: B
authors.lastname: Samuels
authors.forename: Babak
authors.initials: B
authors.lastname: Azabal
authors.forename: Saibal
authors.initials: S
authors.lastname: Kar
authors.forename: Kamlesh
authors.initials: K
authors.lastname: Kothawade
authors.forename: Margo
authors.initials: M
authors.lastname: Minissian
authors.forename: Piotr
authors.initials: P
authors.lastname: Slomka
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
authors.forename: C Noel
authors.initials: CN
authors.lastname: Bairey Merz
keywords: Cardiac myocardial resonance imaging (CMRI); microvascular coronary dysfunction (MCD); myocardial perfusion reserve index (MPRI)