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OBJECTIVES This study is to determine the management and clinical outcomes of patients investigated with coronary computed tomography angiography (CCTA)-derived fractional flow reserve (FFRCT) according to sex.BACKGROUND Women are underdiagnosed with conventional ischemia testing, have lower rates of obstructive coronary artery disease (CAD) at invasive coronary angiography (ICA), yet higher mortality compared to men. Whether FFRCT improves sex-based patient management decisions compared to CCTA alone is unknown.METHODS Subjects with symptoms and CAD on CCTA were enrolled (2015 to 2017). Demographics, symptom status, CCTA anatomy, coronary volume to myocardial mass ratio (V/M), lowest FFRCT values, and management plans were captured. Endpoints included reclassification rate between CCTA and FFRCT management plans, incidence of ICA demonstrating obstructive CAD ($50% stenosis) and revascularization rates.RESULTS A total of 4,737 patients (n = 1,603 females, 33.8%) underwent CCTA and FFRCT. Women were older (age 68 +/- 10 years vs. 65 +/- 10 years; p < 0.0001) with more atypical symptoms (41.5% vs. 33.9%; p < 0.0001). Women had less obstructive CAD (65.4% vs. 74.7%; p < 0.0001) at CCTA, higher FFRCT (0.76 +/- 0.10 vs. 0.73 +/- 0.10; p < 0.0001), and lower likelihood of positive FFRCT

In the absence of disease impacting the coronary arteries or myocardium, there exists a linear relationship between vessel volume and myocardial mass to ensure balanced distribution of blood supply. This balance may be disturbed in diseases of either the coronary artery tree, the myocardium, or both. However, in contemporary evaluation the coronary artery anatomy and myocardium are assessed separately. Recently the coronary lumen volume to myocardial mass ratio (V/M), measured noninvasively using coronary computed tomography angiography (CTCA), has emerged as an integrated measure of myocardial blood supply and demand in vivo. This has the potential to yield new insights into diseases where this balance is altered, thus impacting clinical diagnoses and management. In this review, we outline the scientific methodology underpinning CTCA-derived measurement of V/M. We describe recent studies describing alterations in V/M across a range of cardiovascular conditions, including coronary artery disease, cardiomyopathies and coronary microvascular dysfunction. Lastly, we highlight areas of unmet research need and future directions, where V/M may further enhance our understanding of the pathophysiology of cardiovascular disease.

Objectives: This study is to determine the management and clinical outcomes of patients investigated with coronary computed tomography angiography (CCTA)–derived fractional flow reserve (FFR CT) according to sex. Background: Women are underdiagnosed with conventional ischemia testing, have lower rates of obstructive coronary artery disease (CAD) at invasive coronary angiography (ICA), yet higher mortality compared to men. Whether FFR CT improves sex-based patient management decisions compared to CCTA alone is unknown. Methods: Subjects with symptoms and CAD on CCTA were enrolled (2015 to 2017). Demographics, symptom status, CCTA anatomy, coronary volume to myocardial mass ratio (V/M), lowest FFR CT values, and management plans were captured. Endpoints included reclassification rate between CCTA and FFR CT management plans, incidence of ICA demonstrating obstructive CAD (≥50% stenosis) and revascularization rates. Results: A total of 4,737 patients (n = 1,603 females, 33.8%) underwent CCTA and FFR CT. Women were older (age 68 ± 10 years vs. 65 ± 10 years; p < 0.0001) with more atypical symptoms (41.5% vs. 33.9%; p < 0.0001). Women had less obstructive CAD (65.4% vs. 74.7%; p < 0.0001) at CCTA, higher FFR CT (0.76 ± 0.10 vs. 0.73 ± 0.10; p < 0.0001), and lower likelihood of positive FFR CT ≤ 0.80 for the same degree stenosis (p < 0.0001). A positive FFR CT less than or equal to 0.80 resulted in equal referral to ICA (n = 510 [54.5%] vs. n = 1,249 [56.5%]; p = 0.31), but more nonobstructive CAD (n = 208 [32.1%] vs. n = 354 [24.5%]; p = 0.0003) and less revascularization (n = 294 [31.4%] vs. n = 800 [36.2%]; p < 0.0001) in women, unless the FFR CT was ≤0.75 where revascularization rates were similar (n = 253 [41.9%] vs. n = 715 [46.4%]; p = 0.06). Women have a higher V/M ratio (26.17 ± 7.58 mm 3/g vs. 24.76 ± 7.22 mm 3/g; p < 0.0001) that is associated with higher FFR CT independent of degree stenosis (p < 0.001). Predictors of revascularization included stenosis severity, FFR CT, symptoms, and V/M ratio (p < 0.001) but not female sex (p = 0.284). Conclusions: FFR CT differs between the sexes, as women have a higher FFR CT for the same degree of stenosis. In FFR CT-positive CAD, women have less obstructive CAD at ICA and less revascularization, which is associated with higher V/M ratio. The findings suggest that CAD and FFR CT variations by sex need specific interpretation as these differences may affect therapeutic decision making and clinical outcomes. (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care [ADVANCE]; NCT02499679)