Table 4

Summary of Studies for Sex-Based Differences in Nonobstructive Disease and Endothelial Dysfunction

First Author, Year (Ref. #)Imaging or Intervention UsedSample SizePatient PopulationMain Findings
Nonobstructive coronary disease
 Reynolds et al., 2011 (41)IVUS, MRIN = 50 womenWomen with myocardial infarction were enrolled prospectively, before angiography. Women with ≥50% angiographic stenosis or use of vasospastic agents were excluded.The median angiographic stenosis was 20% and 30% had angiographically normal coronaries; 39% of this cohort had evidence of plaque disruption (29% rupture, 10% erosion) on IVUS and 59% had abnormal findings on MRI (performed within 1 week).
 Tsujita et al., 2013 (43)Grayscale and IVUS-VHN = 42
(54.8% women)
Patients with chest pain and electrocardiography changes who demonstrated VSA were compared with patients with atypical chest pain who did not exhibit VSA.Among patients with VSA, men had more atherogenic lipid and metabolic profiles compared with women without differences in plaque volume or composition.
Patients with VSA had greater plaque volume but similar in plaque composition compared with those without VSA.
Endothelial dysfunction
 Han et al., 2008 (47)Angiography, IVUS, CFRN = 142
(62.7% women)
All patients referred for coronary angiography to evaluate CAD.On IVUS, the atherosclerotic burden in the left main and LAD was greater in men versus women.
Men had more eccentric LAD plaques as well as longer segments with endothelial dysfunction (39.2 [0.0–71.6] mm vs. 11.1 [0.0–38.5] mm, p = 0.002) compared with women.
Women had lower maximal CFR than men (2.80 vs. 3.30, p < 0.001) suggesting greater microvascular dysfunction.
 Murthy et al., 2014 (48)PETN = 1,218
(66.7% women)
Patients referred for evaluation of CAD.CMD was equally prevalent in men and women (51% vs. 54%). Independent of sex, CFR was an incremental predictor of MACE (for every 10% increase in CFR, HR: 0.80; 95% CI: 0.75–0.86).
In a subset of 404 patients without coronary arterial calcification, CMD was equally prevalent in men and women despite a negative stress test result (44% vs. 48%).
 Maruhashi et al., 2013 (50)FMDN = 5,314
(22.3% women)
Cross-sectional study of adults 17–86 years of age who underwent health-screening examinationsMean brachial FMD was higher in women versus men.
In patients without cardiac risk factors, women had higher FMD than men in the age groups of 20–30 years and 40–50 years, beyond which FMD in women declined and equalized with men. In patients with cardiac risk factors, women demonstrated higher FMD only between 20–30 years, beyond which FMD was similar in men and women.
 Benjamin et al., 2014 (51) (Framingham Offspring study)FMDN = 2,883
(52.9% women), mean 61 years of age
Asymptomatic populationAn age-sex interaction was observed for FMD, with steeper age related decline in women (–0.7% vs. –0.5%).

CFR = coronary flow reserve; CMD = coronary microvascular dysfunction; FMD = flow-mediated dilation; MRI = magnetic resonance imaging; PET = positron emission tomography; VSA = vasospastic angina; other abbreviations as in Tables 2 and 3.