Additive effect of coronary artery stenosis on left ventricular myocardial strain in patients with essential hypertension: an analysis of cardiac MRI feature tracking

Abstract

Background: Hypertension is a major cause of adverse left ventricular (LV) remodeling, and co-existing coronary artery stenosis (CAS) may further compromise myocardial function. This study aimed to evaluate the effect of CAS on LV myocardial strain in patients with essential hypertension (EH) using cardiac magnetic resonance imaging (MRI).

Methods: A retrospective analysis was conducted of 173 EH patients [126 with CAS (CAS+) and 47 without CAS (CAS-)] and 52 controls. LV global radial peak strain (GRPS), global circumferential peak strain (GCPS), global longitudinal peak strain (GLPS), and the peak strain rates were evaluated using feature-tracking technology, and compared among the different stenosis severity groups and controls. Spearman correlation and multivariate linear regression analyses were performed to assess the relationship between CAS, as determined by invasive coronary angiography, and the LV myocardial strain parameters evaluated using cardiac MRI.

Results: The EH-CAS+ patients had significantly reduced ejection fraction and higher myocardial mass compared to the EH-CAS- patients and the controls. GCPS and GLPS decreased progressively from the control group to the EH-CAS- group and further to the EH-CAS+ group (all P<0.05). The patients with obstructive coronary artery stenosis (OCAS; luminal stenosis ≥50%) showed significantly reduced LV global peak strain values in all directions compared to those with nonobstructive coronary artery stenosis (NOCAS; luminal stenosis <50%). OCAS was identified as an independent risk factor for the further reduction of myocardial strain in the EH patients (β=-0.170 to -0.251, P<0.05). Significant correlations were found between the Gensini scores and LV strain parameters in the EH patients with OCAS (r=-0.269 to -0.533, P<0.05). The multivariable regression analysis identified the Gensini score as an independent predictor of GRPS (β=-0.327, P<0.01), GCPS (β=-0.365, P<0.05), and GLPS (β=-0.310, P<0.01) in the EH patients.

Conclusions: CAS significantly increases myocardial hypertrophy in EH patients, and OCAS further exacerbates LV dysfunction in these patients. The Gensini score is an independent predictor of LV global peak strain in patients with EH.

Keywords: Gensini score; Hypertension; coronary artery stenosis (CAS); magnetic resonance imaging; myocardial strain.

Figure 1

Representative cardiac magnetic resonance imaging pseudo-color images at the end-systole and peak strain curves in a healthy control (A), an EH patient without CAS (B), and an EH patient with CAS (C), whose age (55.3±2.3 years), sex (male) and BSA (1.65±0.16 m²) were matched. (A1-C1) LV GRPS pseudo-color images in the short axis; (a1-c1) LV GRPS curves; (A2-C2) LV GCPS pseudo-color images in the short axis; (a2-c2) LV GCPS curves; (A3-C3) LV GLPS pseudo-color images in the horizontal four-chamber long axis; (a3-c3) LV GLPS curves. BSA, body surface area; CAS, coronary artery stenosis; EH, essential hypertension; GCPS, global circumferential peak strain; GLPS, global longitudinal peak strain; GRPS, global radial peak strain; LV, left ventricular.

Figure 2

Comparison of LV global strain values among EH patients with different degrees of CAS and controls. Absolute values of LV global strain values were used to avoid the influence of directional sign. *, P<0.05. C, circumferential; EH, essential hypertension; GCPS, global circumferential peak strain; GLPS, global longitudinal peak strain; GRPS, global radial peak strain; L, longitudinal; LV, left ventricular; NOCAS, nonobstructive coronary artery stenosis; OCAS, obstructive coronary artery stenosis; PDSR, peak diastole strain rate; PSSR, peak systole strain rate; R, radial.

Figure 3

Correlation between LV global peak strain and the Gensini score in EH patients with OCAS. EH, essential hypertension; GCPS, global circumferential peak strain; GLPS, global longitudinal peak strain; GRPS, global radial peak strain; LV, left ventricular; OCAS, obstructive coronary artery stenosis; PDSR, peak diastole strain rate; PSSR, peak systole strain rate.