Association between left atrial function using multimodality tissue tracking from cine MRI and myocardial scar in the multi-ethnic study of atherosclerosis (MESA)
Masamichi Imai
2
Bharath Ambale Venkatesh
2
Sanaz Samiei
2
Mohammadali Habibi
1
Anderson C Armstrong
2
Susan Heckbert
0
Sirisha Donekal
2
David A Bluemke
3
Colin O Wu
3
Joao A Lima
2
From
th Annual SCMR Scientific Sessions San Francisco
CA
USA.
January -
0
February
0
Washington University
,
Washington, DC, DC
,
USA
1
Union memorial Hospital
,
Baltimore, MD
,
USA
2
Johns Hopkins University
,
Baltimore, MD
,
USA
3
National Institutes of Health
,
Bethesda, MD
,
USA
-
Background
Left atrial (LA) function is strongly related to left
ventricular (LV) filling pressures and has shown association to
cardiovascular outcomes. A recently developed speckle
tracking technique can assess LA deformation using
CMR cine sequences. Myocardial scar assessed by late
gadolinium enhancement (LGE-CMR) relates to cardiac
remodeling, but its association to LA function is
unknown. We explored the relationship of LA function
with the amount of myocardial scar.
Methods
A total of 1666 participants from the MESA, age range
55-94 yrs, underwent LGE-CMR using 1.5T scanners at
six field centers. Myocardial scar was visually detected,
classified (ischemic/non-ischemic), and quantified using
semi-automated methods in 136 participants. The
amount of scar was quantified as the ratio of scar mass
over total LV mass and values greater than 5% were
defined as clinically significant. LA function was
evaluated using multimodality tissue tracking (MTT) from
SSFP 2- and 4-chamber long-axis cine CMR images in all
participants with myocardial scar and in an age and
gender matched control group of 136 participants without
scar. LA function was assessed using peak longitudinal
strain (Smax), diastolic longitudinal strain rate (SRdia),
ejection fraction (LAEF), emptying fraction (LAEmF),
and LA maximum volume (Vmax). Wilcoxon rank-sum
test was used to evaluate differences between groups:
1Johns Hopkins University, Baltimore, MD, USA
Full list of author information is available at the end of the article
control, scar>5%, and scar<5%. Pearsons correlation
assessed the relationship between the amount of scar and
LA function parameters.
Results
From the total of 136 participants with myocardial scar
(729 yrs, 86% male, 48% ischemic), 43 participants had
scars that were clinically significant (748 yrs, 86% male,
98% ischemic). No significant difference was found
between the groups for Vmax and LAEF. LAEmF, Smax,
and SRdia were the most robust parameters comparing
the groups (Table 1). Both the strain parameters were
significantly different between the control and the
scar>5% groups while for LAEmF the difference was
marginal (p=0.05). SRdia and LAEmF were significant when
the scar>5% and scar<5% groups were compared, while
Smax was marginally different (p=0.06). None of the
parameters differed between the control and the scar<5%
groups. The percent LV scar correlated significantly with
LAEmF (r=-0.21, p=<0.02), Smax (r=-0.18, p<0.04), and
SRdia (r=0.18, p=0.04) but not with Vmax (p=0.08) and
LAEF (p=0.20).
Conclusions
LA parameters are associated with cardiac remodeling in
clinically significant myocardial scar. LAEmF, Smax and
SRdia are more sensitive to changes in cardiac function
resulting from the presence of myocardial scar than
traditional LA functional parameters Vmax and LAEF.
Table 1 Comparison among control group, scar<5% group, and scar>5% group with peak volume, LA ejection
fraction, LA emptying fraction, peak strain, and peak diastolic strain rate. * p<0.05 for comparison between scar<5%
and scar>5% groups. ^ p<0.05 for comparison between control and scar>5% groups
Funding
NHLBI N01-HC-95159
NHLBI N01-HC-95168
NCRR UL1-RR-024156
NCRR UL1-RR-025005.
(...truncated)