Thorac Cardiovasc Surg 2014; 62 - v28
DOI: 10.1055/s-0034-1394004

Abnormalities of myocardial blood flow, viability and diffuse fibrosis in patients after Arterial Switch and Ross Operation assessed with magnetic resonance imaging

P. Wegner 1, HM. Pham 1, M. Jerosch-Herold 2, I. Voges 1, I. Christo 1, A.C. Andrade 1, C. Hart 1, C. Rickers 1, H.-H. Kramer 1
  • 1University Hospital of Schleswig-Holstein, Paediatric Cardiology, Children's Hospital, Kiel
  • 2Brigham and Women's Hospital, Harvard Medical School, Boston, USA

Background: Myocardial blood flow (mbf) after coronary transfer during arterial switch operation or Ross operation may not only be disturbed by coronary obstruction, but also by functional changes in terms of reduced vasodilatory capacity. This was investigated in 25 patients (pts) with transposition of the great arteries and 11 pts with aortic valve disease.

Purpose: We utilized advanced CMR methods to assess mbf, viability and diffuse fibrosis in pts with patent (n=23) and obstructed/narrowed (n=13) coronary arteries.

Methods: MRI first-pass perfusion for calculating quantitative blood flow at rest and stress (ml/g/min), late enhancement studies for detecting myocardial scar tissue and a Look-Locker technique for detecting diffuse fibrosis were performed in 36 pts (age, 15.8±10.9 yrs) and 10 age matched healthy controls.

Results: In all pts with patent epicardial coronary arteries myocardial perfusion reserve (mpr) was significantly reduced as compared to healthy controls (2.79±0.75 vs. 3.75±1.13; p<0.05). T1 mapping showed increased extracellular matrix expansion (esv) suggestive of diffuse fibrosis (0.37±0.09 vs. 0.26±0.02; p<0.05). Among the 13 pts with some type of obstruction of epicardial coronary arteries we found 5 pts with regional or global impairment of LV function, 7 pts with regional ischemia and 4 pts with scar tissue.

Conclusions: Even after a perfect coronary transfer pts show an impaired myocardial perfusion reserve and increased interstitial fibrosis. In pts with anatomical coronary problems CMR imaging is of high value to guide therapeutical planning.