2262
JACC VOL. 65, NO. 20, 2015
Letters
MAY 26, 2015:2257–64
6th Floor, Burnett-Womack Building
the aortic distensibility is decreased, an expanded
160 Dental Circle CB#7075
aorta may be able to store enough blood during sys-
Chapel Hill, North Carolina 27599-7075
tole, which resembles the compensation of a failing
E-mail: [email protected]
heart; that is, although the left ventricular ejection
http://dx.doi.org/10.1016/j.jacc.2015.03.536
fraction is decreased, the increased left ventricular
Please note: All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
end-diastolic volume can maintain sufficient cardiac output. Actually, our patients demonstrated aortic
REFERENCE
dilation (2) (so-called “aortopathy” in congenital
1. Yadav PK, Halim SA, Vavalle JP. Training in structural heart interventions. J Am Coll Cardiol 2014;64:2296–8.
the aortas in elderly people are not only stiff, but also
heart diseases [5]). In addition, it is well known that dilated (3).
Aortic Stiffening and Dilation Influence on Coronary Supply–Demand Balance
We would like to know whether the aortic diameter was related to its distensibility in Redheuil et al.’s study (1). Moreover, we are interested in the subendocardial viability ratio and the tension time index of the patients in their study.
We read with great interest the article by Redheuil
*Tomoaki Murakami, MD, PhD Koichiro Niwa, MD, PhD
et al. (1), which reported that proximal aortic disten-
*Department of Cardiology
sibility was an independent predictor of all-cause
Chiba Children’s Hospital
mortality and incidence of further cardiovascular
579-1 Heta-cho
events. Concerning congenital heart diseases, there
Midori-ku, Chiba 266-0007
are lots of reports about the decreased distensibility of
Japan
native and post-operative aortas. We previously re-
E-mail: [email protected]
ported the decreased ascending aortic distensibility in
http://dx.doi.org/10.1016/j.jacc.2015.01.063
patients with transposition of the great arteries after arterial switch procedure (2). The decreased aortic distensibility increases the afterload of the left ventricle and is a disadvantage for coronary circulation (3). Therefore, we also examined the subendocardial viability ratio in those patients (4). The subendocardial viability ratio is the ratio of the aortic diastolic pressure time integral and the aortic systolic pressure time integral (tension time index), that is, a measure of hemodynamic capacity for supply divided by myocardial oxygen demand. In that study, the tension time index, which indicates the myocardial oxygen demand, was higher than that in the control subjects, although the
Please note: Both authors have reported that they have no relationships relevant to the contents of this paper to disclose.
REFERENCES 1. Redheuil A, Wu CO, Kachenoura N, et al. Proximal aortic distensibility is an independent predictor of all-cause mortality and incident CV events: the MESA study. J Am Coll Cardiol 2014;64:2619–29. 2. Murakami T, Nakazawa M, Momma K, et al. Impaired distensibility of neoaorta after arterial switch procedure. Ann Thorac Surg 2000;70:1907–10. 3. O’Rourke MF, Safar ME, Dzau V. The cardiovascular continuum extended: aging effects on the aorta and microvasculature. Vasc Med 2010;15:461–8. 4. Murakami T, Takei K, Ueno M, et al. Aortic reservoir function after arterial switch operation in elementary school-aged children. Circ J 2008; 72:1291–5.
subendocardial viability ratio was the same. This
5. Niwa K. Aortopathy in congenital heart disease in adults: aortic dilatation with decreased aortic elasticity that impacts negatively on left ventricular
pattern of the aortic pressure waveform, an elevated
function. Korean Circ J 2013;43:215–20.
tension time index without a decrease of the subendocardial viability ratio, is similar to that in elderly
REPLY: Aortic Stiffening and Dilation
people, although the patients in our study were
Influence on Coronary Supply–Demand Balance
elementary school–aged children. Because preserving the coronary supply–demand
We wish to thank Drs. Murakami and Niwa for their
balance is essential to sustain life, the subendocardial
interest in our work and their very insightful com-
viability ratio should be maintained constant even
ments. Concerning congenital heart disease, in
in conditions with decreased aortic distensibility.
particular arterial switch for transposition of the great
Because the decreased aortic distensibility increases
arteries correction, we agree that altered myocardial
left ventricular workload, it is necessary to increase
oxygen supply is multifactorial and that the proximal
“supply,” although the stiff aorta is a disadvantage
aorta may play a role in several ways. First, the
for coronary circulation (3). In our opinion, 1 of the
evolution and aging of the neoaorta-associating dila-
solutions to the problem is aortic dilation. Although
tion, elongation, and rotation processes may lead to
JACC VOL. 65, NO. 20, 2015
Letters
MAY 26, 2015:2257–64
6th Floor, Burnett-Womack Building
the aortic distensibility is decreased, an expanded
160 Dental Circle CB#7075
aorta may be able to store enough blood during sys-
Chapel Hill, North Carolina 27599-7075
tole, which resembles the compensation of a failing
E-mail: [email protected]
heart; that is, although the left ventricular ejection
http://dx.doi.org/10.1016/j.jacc.2015.03.536
fraction is decreased, the increased left ventricular
Please note: All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
end-diastolic volume can maintain sufficient cardiac output. Actually, our patients demonstrated aortic
REFERENCE
dilation (2) (so-called “aortopathy” in congenital
1. Yadav PK, Halim SA, Vavalle JP. Training in structural heart interventions. J Am Coll Cardiol 2014;64:2296–8.
the aortas in elderly people are not only stiff, but also
heart diseases [5]). In addition, it is well known that dilated (3).
Aortic Stiffening and Dilation Influence on Coronary Supply–Demand Balance
We would like to know whether the aortic diameter was related to its distensibility in Redheuil et al.’s study (1). Moreover, we are interested in the subendocardial viability ratio and the tension time index of the patients in their study.
We read with great interest the article by Redheuil
*Tomoaki Murakami, MD, PhD Koichiro Niwa, MD, PhD
et al. (1), which reported that proximal aortic disten-
*Department of Cardiology
sibility was an independent predictor of all-cause
Chiba Children’s Hospital
mortality and incidence of further cardiovascular
579-1 Heta-cho
events. Concerning congenital heart diseases, there
Midori-ku, Chiba 266-0007
are lots of reports about the decreased distensibility of
Japan
native and post-operative aortas. We previously re-
E-mail: [email protected]
ported the decreased ascending aortic distensibility in
http://dx.doi.org/10.1016/j.jacc.2015.01.063
patients with transposition of the great arteries after arterial switch procedure (2). The decreased aortic distensibility increases the afterload of the left ventricle and is a disadvantage for coronary circulation (3). Therefore, we also examined the subendocardial viability ratio in those patients (4). The subendocardial viability ratio is the ratio of the aortic diastolic pressure time integral and the aortic systolic pressure time integral (tension time index), that is, a measure of hemodynamic capacity for supply divided by myocardial oxygen demand. In that study, the tension time index, which indicates the myocardial oxygen demand, was higher than that in the control subjects, although the
Please note: Both authors have reported that they have no relationships relevant to the contents of this paper to disclose.
REFERENCES 1. Redheuil A, Wu CO, Kachenoura N, et al. Proximal aortic distensibility is an independent predictor of all-cause mortality and incident CV events: the MESA study. J Am Coll Cardiol 2014;64:2619–29. 2. Murakami T, Nakazawa M, Momma K, et al. Impaired distensibility of neoaorta after arterial switch procedure. Ann Thorac Surg 2000;70:1907–10. 3. O’Rourke MF, Safar ME, Dzau V. The cardiovascular continuum extended: aging effects on the aorta and microvasculature. Vasc Med 2010;15:461–8. 4. Murakami T, Takei K, Ueno M, et al. Aortic reservoir function after arterial switch operation in elementary school-aged children. Circ J 2008; 72:1291–5.
subendocardial viability ratio was the same. This
5. Niwa K. Aortopathy in congenital heart disease in adults: aortic dilatation with decreased aortic elasticity that impacts negatively on left ventricular
pattern of the aortic pressure waveform, an elevated
function. Korean Circ J 2013;43:215–20.
tension time index without a decrease of the subendocardial viability ratio, is similar to that in elderly
REPLY: Aortic Stiffening and Dilation
people, although the patients in our study were
Influence on Coronary Supply–Demand Balance
elementary school–aged children. Because preserving the coronary supply–demand
We wish to thank Drs. Murakami and Niwa for their
balance is essential to sustain life, the subendocardial
interest in our work and their very insightful com-
viability ratio should be maintained constant even
ments. Concerning congenital heart disease, in
in conditions with decreased aortic distensibility.
particular arterial switch for transposition of the great
Because the decreased aortic distensibility increases
arteries correction, we agree that altered myocardial
left ventricular workload, it is necessary to increase
oxygen supply is multifactorial and that the proximal
“supply,” although the stiff aorta is a disadvantage
aorta may play a role in several ways. First, the
for coronary circulation (3). In our opinion, 1 of the
evolution and aging of the neoaorta-associating dila-
solutions to the problem is aortic dilation. Although
tion, elongation, and rotation processes may lead to
