Left ventricular concentric remodelling and functional impairment in women with ischaemia with no obstructive coronary artery disease and intermediate coronary flow reserve: a report from the WISE-CVD study

Abstract

Aims: Women with evidence of ischaemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Although invasively measured coronary flow reserve (CFR) is useful for the diagnosis of CMD, intermediate CFR values are often found of uncertain significance. We investigated myocardial flow reserve and left ventricular (LV) structural and functional remodelling in women with suspected INOCA and intermediate CFR.

Methods and results: Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study participants who had invasively measured intermediate CFR of 2.0≤ CFR ≤3.0 (n = 125) were included for this analysis. LV strain, peak filling rate (PFR) and myocardial perfusion reserve index (MPRI) were obtained by cardiac magnetic resonance imaging. Participants were divided: (i) Group 1 (n = 66) high MPRI ≥ 1.8, and (ii) Group 2 (n = 59) low MPRI < 1.8. The mean age was 54 ± 12 years and CFR was 2.46 ± 0.27. MPRI was significantly different but CFR did not differ between groups. LV relative wall thickness (RWT) trended higher in Group 2 and circumferential peak systolic strain and early diastolic strain rate were lower (P = 0.039 and P = 0.035, respectively), despite a similar LV ejection fraction and LV mass. PFR was higher in Group 1 and LV RWT was negatively related to PFR (r = -0.296, P = 0.001).

Conclusions: In women with suspected INOCA and intermediate CFR, those with lower MPRI had a trend towards more adverse remodelling and impaired diastolic LV function compared with those with higher MPRI. CFR was similar between the two groups. These findings provide evidence that both coronary microvessel vasomotion and structural and functional myocardial remodelling contribute to CMD.

Keywords: cardiac magnetic resonance; coronary flow reserve; coronary microvascular dysfunction; remodelling; women.

Figure 1

Subject flow chart. CFR, coronary flow reserve; CMRI, cardiac magnetic resonance imaging; CRT, coronary reactivity testing; LGE, late gadolinium enhancement.

Figure 2

Myocardial tissue feature tracking in a representative ventricular short-axis cine image. (A) Contours are drawn on the endocardial and epicardial boarders at a single phase of the cardiac cycle. (B) Global circumferential strain (GCS) curve from basal to apical all segments is shown throughout the cardiac cycle. (C) Circumferential early diastolic strain rate (CSRe) was automatically calculated as the time derivative of circumferential strain from (B).