Aortic Stiffness and Infarct Healing in Survivors of Acute ST‐Segment–Elevation Myocardial Infarction

BACKGROUND: In survivors of acute ST‐segment–elevation myocardial infarction (STEMI), increased aortic stiffness is associated with worse clinical outcome; however, the underlying pathomechanisms are incompletely understood. We aimed to investigate associations between aortic stiffness and infarct healing using comprehensive cardiac magnetic resonance imaging in patients with acute STEMI. METHODS AND RESULTS: This was a prospective observational study including 103 consecutive STEMI patients treated with primary percutaneous coronary intervention. Pulse wave velocity (PWV), the reference standard for aortic stiffness assessment, was determined by a validated phase‐contrast cardiac magnetic resonance imaging protocol within the first week after STEMI. Infarct healing, defined as relative infarct size reduction from baseline to 4 months post‐STEMI, was determined using late gadolinium‐enhanced cardiac magnetic resonance. Median infarct size significantly decreased from 17% of left ventricular mass (interquartile range 9% to 28%) at baseline to 12% (6% to 17%) at 4‐month follow‐up (P<0.001). Relative infarct size reduction was 36% (interquartile range 15% to 52%). Patients with a reduction >36% were younger (P=0.01) and had lower baseline NT‐proBNP (N‐terminal pro–B‐type natriuretic peptide) concentrations (P=0.047) and aortic PWV values (P=0.003). In a continuous (odds ratio 0.64 [95% CI, 0.49–0.84]; P=0.001) as well as categorical (PWV <7 m/s; odds ratio 4.80 [95% CI, 1.89–12.20]; P=0.001) multivariable logistic regression model, the relation between aortic PWV and relative infarct size reduction remained significant after adjustment for baseline infarct size, age, NT‐proBNP, and C‐reactive protein. CONCLUSIONS: Aortic PWV independently predicted infarct size reduction as assessed by cardiac magnetic resonance, revealing a novel pathophysiological link between aortic stiffness and adverse infarct healing during the early phase after STEMI treated with contemporary primary percutaneous coronary intervention.