Aortic stiffness is associated with elevated high-sensitivity cardiac troponin T concentrations at a chronic stage after ST-segment elevation myocardial infarction.

OBJECTIVES: Aortic pulse wave velocity (PWV)--the proposed gold standard for the assessment of aortic stiffness--is a major determinant of left ventricular after-load and coronary perfusion. We aimed to investigate the association between aortic PWV and subclinical elevation of high-sensitivity cardiac troponin T (hs-TnT) concentrations at a chronic stage after acute ST-segment elevation myocardial infarction (STEMI). METHODS: Seventy-four patients with acute STEMI were included in this cross-sectional single-centre study at the University Hospital of Innsbruck. All patients underwent cardiac MRI for the assessment of left ventricular function, morphology, infarct size and aortic PWV 12 months after acute STEMI. Blood samples were drawn at 12 months by peripheral venipuncture. Levels of hs-TnT were measured by a commercially available immunoassay (Roche Diagnostics). RESULTS: hs-TnT levels (6.4 ng/l, inter-quartile range 5.0-8.6) were significantly associated with age (r = 0.417, P < 0.001), plasma creatinine levels (r = 0.257, P = 0.027), high-sensitivity C-reactive protein levels (r = 0.281, P = 0.015) and aortic PWV (r = 0.435, P < 0.001). Multiple linear regression analysis revealed aortic PWV (ß = 0.330, P = 0.025), apart from plasma creatinine concentrations (ß = 0.279, P = 0.010), to be independently associated with hs-TnT concentrations (model: R = 0.597, P < 0.001). CONCLUSION: The present study showed an association of aortic stiffness and hs-TnT concentrations at a chronic stage after STEMI.

Comparison of an oscillometric method with cardiac magnetic resonance for the analysis of aortic pulse wave velocity.

OBJECTIVES: Pulse wave velocity (PWV) is the proposed gold-standard for the assessment of aortic elastic properties. The aim of this study was to compare aortic PWV determined by a recently developed oscillometric device with cardiac magnetic resonance imaging (CMR). METHODS: PWV was assessed in 40 volunteers with two different methods. The oscillometric method (PWVOSC) is based on a transfer function from the brachial pressure waves determined by oscillometric blood pressure measurements with a common cuff (Mobil-O-Graph, I.E.M. Stolberg, Germany). CMR was used to determine aortic PWVCMR with the use of the transit time method based on phase-contrast imaging at the level of the ascending and abdominal aorta on a clinical 1.5 Tesla scanner (Siemens, Erlangen, Germany). RESULTS: The median age of the study population was 34 years (IQR: 24-55 years, 11 females). A very strong correlation was found between PWVOSC and PWVCMR (r = 0.859, p < 0.001). Mean PWVOSC was 6.7 ± 1.8 m/s and mean PWVCMR was 6.1 ± 1.8 m/s (p < 0.001). Analysis of agreement between the two measurements using Bland-Altman method showed a bias of 0.57 m/s (upper and lower limit of agreement: 2.49 m/s and -1.34 m/s). The corresponding coefficient of variation between both measurements was 15%. CONCLUSION: Aortic pulse wave velocity assessed by transformation of the brachial pressure waveform showed an acceptable agreement with the CMR-derived transit time method.