Resonancia magnética para la detección no invasiva de la enfermedad microcirculatoria asociada a la vasculopatía de alotrasplante: validación de la determinación intracoronaria

Abstract

Introduction and objectivesCardiac allograft vasculopathy affects both epicardial and microcirculatory coronary compartments. Magnetic resonance perfusion imaging has been proposed as a useful tool to assess microcirculation mostly outside the heart transplantation setting. Instantaneous hyperemic diastolic flow velocity-pressure slope, an intracoronary physiology index, has demonstrated a better correlation with microcirculatory remodelling in cardiac allograft vasculopathy than other indices such as coronary flow velocity reserve. To investigate the potential of magnetic resonance perfusion imaging to detect the presence of microcirculatory remodeling in cardiac allograft vasculopathy, we compared magnetic resonance perfusion data with invasive intracoronary physiological indices to study microcirculation in a population of heart transplantation recipients with macrovascular nonobstructive disease demonstrated with intravascular ultrasound. MethodsWe studied 8 heart transplantation recipients (mean age, 61 [12] years, 100% male) with epicardial allograft vasculopathy defined by intravascular ultrasound, nonsignificant coronary stenoses and negative visually-assessed wall-motion/perfusion dobutamine stress magnetic resonance. Quantitative stress and rest magnetic resonance perfusion data to build myocardial perfusion reserve index, noninvasively, and 4 invasive intracoronary physiological indices were determined. ResultsPostprocessed data showed a mean (standard deviation) myocardial perfusion reserve index of 1.22 (0.27), while fractional flow reserve, coronary flow velocity reserve, hyperemic microvascular resistance and instantaneous hyperemic diastolic flow velocity-pressure slope were 0.98 (0.02) cm/s/mmHg, 2.34 (0.55) cm/s/mmHg, 2.00 (0.69) cm/s/mmHg, and 0.91 (0.65) cm/s/mmHg, respectively. The myocardial perfusion reserve index correlated strongly only with the instantaneous hyperemic diastolic flow velocity-pressure slope (r = 0.75; P = .033). ConclusionsMyocardial perfusion reserve index derived from a comprehensive dobutamine stress magnetic resonance appears to be a reliable technique for noninvasive detection of microcirculatory coronary disease associated with cardiac allograft vasculopathy.Full English text available from:www.revespcardiol.org/en