Use and limitations of cardiac magnetic resonance derived measures of aortic stiffness in patients after acute myocardial infarction

Abstract

Introduction: Cardiac magnetic resonance (CMR) is a unique method to determine regional and local aortic stiffness parameters. Although various methods have been validated, there are no data in patients after acute ST-segment elevation myocardial infarction (STEMI). In the present study we assessed the feasibility of different CMR derived measures of aortic stiffness in patients after first acute STEMI for the first time.

Methods: CMR derived aortic pulse wave velocity (PWV) determined by the regional transit-time (PWVTT) and local flow-area (PWVQA) method as well as local distensibility coefficients (DCs) was analyzed in 22 healthy young volunteers and 28 patients with recent acute STEMI.

Results: PWVTT and DC of the ascending aorta differed significantly between healthy subjects and STEMI patients (all p<0.001). PWVQA at thoracic levels of aorta was not different between groups (p>0.520) and did not correlate with age (p>0.149) and PWVTT (p>0.310). Intra- and interobserver variability was high for PWVTT (r=0.970, p<0.001 and r=0.920, p<0.001), acceptable for DC (all r>0. 809, p<0.001 and all r>0.510, p<0.001) but low for thoracic PWVQA (all r<0.330 and all r<0.372).

Conclusion: PWVTT and local DC are robust methods for the assessment of aortic stiffness in patients after acute STEMI.

Keywords: Acute myocardial infarction; Aortic stiffness; Cardiac magnetic resonance; Distensibility coefficients; Local aortic elastic properties; Pulse wave velocity.