1 research outputs found
Dynamic Edematous Response of the Human Heart to Myocardial Infarction Implications for Assessing Myocardial Area at Risk and Salvage
BACKGROUND: Clinical protocols aimed to characterize the post-myocardial
infarction (MI) heart by cardiac magnetic resonance (CMR) need to be
standardized to take account of dynamic biological phenomena evolving
early after the index ischemic event. Here, we evaluated the time course
of edema reaction in patients with ST-segment-elevation MI by CMR and
assessed its implications for myocardium-at-risk (MaR) quantification
both in patients and in a large-animal model.
METHODS: A total of 16 patients with anterior ST-segment-elevation MI
successfully treated by primary angioplasty and 16 matched controls were
prospectively recruited. In total, 94 clinical CMR examinations were
performed: patients with ST-segment-elevation MI were serially scanned
(within the first 3 hours after reperfusion and at 1, 4, 7, and 40
days), and controls were scanned only once. T2 relaxation time in the
myocardium (T2 mapping) and the extent of edema on T2-weighted short-tau
triple inversion-recovery (ie, CMR-MaR) were evaluated at all time
points. In the experimental study, 20 pigs underwent 40-minute
ischemia/reperfusion followed by serial CMR examinations at 120 minutes
and 1, 4, and 7 days after reperfusion. Reference MaR was assessed by
contrast-multidetector computed tomography during the index coronary
occlusion. Generalized linear mixed models were used to take account of
repeated measurements.
RESULTS: In humans, T2 relaxation time in the ischemic myocardium
declines significantly from early after reperfusion to 24 hours, and
then increases up to day 4, reaching a plateau from which it decreases
from day 7. Consequently, edema extent measured by T2-weighted short-tau
triple inversion-recovery (CMR-MaR) varied with the timing of the CMR
examination. These findings were confirmed in the experimental model by
showing that only CMR-MaR values for day 4 and day 7 postreperfusion,
coinciding with the deferred edema wave, were similar to values measured
by reference contrast-multidetector computed tomography.
CONCLUSIONS: Post-MI edema in patients follows a bimodal pattern that
affects CMR estimates of MaR. Dynamic changes in
post-ST-segment-elevation MI edema highlight the need for
standardization of CMR timing to retrospectively delineate MaR and
quantify myocardial salvage. According to the present clinical and
experimental data, a time window between days 4 and 7 post-MI seems a
good compromise solution for standardization. Further studies are needed
to study the effect of other factors on these variables.This study was partially supported by a competitive grant from the
Spanish Society of Cardiology (Proyectos de Investigacion Traslacional
en Cardiologia de la Sociedad Espanola de Cardiologia 2015, for the
project Caracterizacion tiSUlar miocaRdica con resonancia magnetica en
pacientes tras inFarto agudo de mioCardio con elevacioN de ST sometidos
a angloplastia Coronaria primaria. Estudio SURF-CNIC), by a competitive
grant from the Carlos III Institute of Health-Fondo de Investigacion
Sanitaria- and the European Regional Development Fund (ERDF/FEDER)
(PI10/02268 and PI13/01979), the Spanish Ministry of economy, industry,
and competitiveness (MEIC) and ERDF/FEDER SAF2013-49663-EXP. Dr
Fernandez-Jimenez holds a FICNIC fellowship from the Fundacio Jesus
Serra, the Fundacion Interhospitalaria de Investigacion Cardiovascular,
and the Centro Nacional de Investigaciones Cardiovasculares Carlos III
(CNIC), and Dr Aguero is a FP7-PEOPLE-2013-ITN-Cardionext fellow. This
study forms part of a Master Research Agreement between the CNIC and
Philips Healthcare, and is part of a bilateral research program between
Hospital de Salamanca Cardiology Department and the CNIC. This research
program is part of an institutional agreement between FIIS-Fundacion
Jimenez Diaz and CNIC. The CNIC is supported by the MEIC and the Pro
CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award
SEV-2015-0505).S