- Email: [email protected]
Accurate Echocardiographic Assessment of Left Atrial Appendage Ostium and Peri-Device Flow in Device Closure
1432
Correspondence
JACC Vol. 60, No. 15, 2012 October 9, 2012:1430–7
largest ski race, ongoing in Sweden since 1922, with a total of 926,350 participants through 2010. The last 10 years accounts for 45% of these skiers, with the addition of shorter distances as an option. During 90 years of ski racing, 20 cases (mean age 55 years) of CA occurred, 5 of which survived (mean age 47 years) the acute event. All cases were men, and had support of bystander cardiopulmonary resuscitation (CPR). Coronary heart disease was the cause of CA for 16 skiers. Two had hypertrophic cardiomyopathy, 1 had myocarditis, and 1 had ventricular fibrillation of unknown cause. The incidence proportion of CA was 2.16 per 100,000 skiers. The incidence rate was 0.31 per 100,000 skiing hours. The incidence rate was 0.46 per 100,000 racing hours in the last decade compared with 0.22 per 100,000 hours of skiing from 1922 to 2000. The mean distance until CA occurred was 25.7 ⫾ 15.8 km (95% confidence intervals [CI]: 6 to 45) for the survivors, and the distance for nonsurvivors was 33.6 ⫾ 29.8 km (95% CI: 17 to 50). The absolute risk of CA during the ski race is low. Nevertheless, the relative risk seems to be much higher than expected, considering the incidence in the race (4,030 per 100,000 person-years of skiing in the last decade) compared with the normal out-ofhospital CA rate (range, 13 to 52 by region per 100,000 personyears in recent years) in the general Swedish population (3). The risk for CA with the vigorous physical activity was very similar to long-distance running (1.01 per 100,000 for runners) and skiing (1). However, the timing of the occurrence was different. Although CA occurred mainly during the last quarter for runners, it occurred mainly in the first third of the ski race. This may indicate different trigger mechanisms for the induction of CA in different temperatures (2). A striking similarity between the running and the ski races was that the fatality rates were 75% and 71%, respectively, despite the 10-year higher mean age of the skiers. The possibility of survival is probably dependent of the active efforts of bystander CPR. The incidence rate in Vasaloppet has increased in the last decade, which may result from participation of less-trained people due to a greater public interest in exercise. It is important that the organizers of this kind of sporting event take responsibility for healthcare and rescue activities (4). Considering the relatively low absolute risk of CA, we are, however, convinced that the overall benefit of regular physical activity to public health is much larger than the risk of CA (5). *Ulf Hållmarker, MD Karl Michaëlsson, MD, PhD ¨ rnlöv, MD, PhD Johan A Stefan James, MD, PhD *Mora Lasarett Department of Internal Medicine, Department of Medical Science Uppsala University 792 85 Mora Sweden E-mail: [email protected] http://dx.doi.org/10.1016/j.jacc.2012.05.046 Please note: Dr. James has received institutional grants from AstraZeneca, Eli Lilly, BMS, Terumo Inc., Medtronic, and Vascular Solutions; and honoraria from AstraZeneca, Eli Lilly, Merck, Sanofi, and Abbott Vascular. All other author have reported that they have no relationships relevant to the contents of this paper to disclose.
REFERENCES
1. Kim Jonathan H, Rajeev M, et al. Cardiac arrest during long-distance running races. N Engl J Med 2012;366:130 – 40. 2. Bhaskaran K, Hajat S, Haines A, Herrett E, Wilkinson P, Smeeth L. Effects of ambient temperature on the incidence of myocardial infarction. Heart 2009;95:1760 –9. 3. Stromsoe A, Svensson L, Claesson A, Lindkvist J, Lundstrom A, Herlitz J. Association between population density and reported incidence, characteristics and outcome after out-of-hospital cardiac arrest in Sweden. Resuscitation 2011;82:1307–13. 4. Hållmarker U, Aronson D, Jansson A, Hamraeus K, Sjögren I. Cardiac arrest in the tracks of the forefathers (Hjärtstopp i fädrens spår Vasaloppet 2010). Läkartidningen 2010;107:2720 –2. 5. Fahramand BY, Ahlbom A, Ekblom Ö, et al. Mortality amongst participants in Vasaloppet: a classical long-distance ski race in Sweden. J Intern Med 2003;253:276 – 83.
Letters to the Editor
Accurate Echocardiographic Assessment of Left Atrial Appendage Ostium and Peri-Device Flow in Device Closure I read with interest the report by Viles-Gonzalez et al. (1), which indicated that residual peri-device flow into the left atrial appendage (LAA) after percutaneous closure with the Watchman device was common, and not associated with an increased risk of thromboembolism. Transesophageal echocardiography (TEE) was performed, and follow-up revealed that 32% of implanted patients had at least some degree of peri-device flow (“leak”) at 12 months. Although such observations are unique with a large sample available from the PROTECT AF (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial, the methodology and analytical data used to reach conclusions regarding risk of thromboembolism warrant further discussion. Accurate echocardiographic measurement of the LAA anatomy, especially of the ostium, is critically important for successful LAA ostial closure using the Watchman device. The echocardiographic ostium of the LAA, which is usually measured from the junction of the upper left pulmonary vein entering the LA to the junction of the LA and LAA, is somewhat larger than the anatomic ostium (2). The maximal LAA ostial diameter can be obtained and used as an accurate reference for LAA ostial diameter measured at baseline from TEE or intracardiac echocardiographic (ICE) LAA imaging views (3,4) (Fig. 1A). Viles-Gonzalez et al. (1) indicated that “there was a wide variation on the size of the LAA ostium width and length at baseline” and reported that “the mean LAA ostium width at baseline was 21.9 ⫾ 4.1 mm. . .The mean ostium length at baseline was 49.4 ⫾ 9.1 mm.” Obviously, such a large ostium length could not exist even in patients with atrial fibrillation (AF) and would be impossible to close with the largest Watchman device (33 mm). However, these LAA diameters are comparable with our measurements of the maximal short (18 ⫾ 4 mm) and long (50 ⫾ 9 mm) axes of LAA
Correspondence
JACC Vol. 60, No. 15, 2012 October 9, 2012:1430–7
Figure 1
1433
Intracardiac Echocardiographic Imaging of Left Atrial (LA) Appendage (LAA)
(A) The transducer is placed in the right ventricular outflow tract, showing the LAA ostium (Os; diameter ⫽ 18 mm, between the two white horizontal arrows) and the Watchman device (struts, arrows) located at the LAA Os, (B) The transducer is placed in the pulmonary artery (PA), showing the closure device (arrows) properly located at the LAA Os without peri-device flow seen around the LAA Os side. A blue color flow image in the LA side only indicates a slight “pit” region. Ao ⫽ aortic root; ulpv ⫽ upper left pulmonary vein.
body size in patients with AF (n ⫽ 42) using ICE imaging. The question is whether they measured the LAA ostium or just the LAA body size. Regarding peri-device flow (leak), Viles-Gonzalez et al. (1) explained that a peri-device flow would be the mismatch between the circular device and the typically oval LAA orifice and the subsequent inadequacy of circumferential LAA sealing. I disagree with this explanation of “shape mismatch” conception. Accurate measurement of maximal LAA ostial diameter is much more important than shape, because the LAA ostium is mainly a soft tissue structure that can be expanded and fit completely to the device shape if the device is placed at an optimal location. ICE LAA ostium imaging with color Doppler flow can reliably confirm the optimal location without any peri-device flow. Of note, to evaluate the peri-device flow (leak), LAA emptying flow is more important than the “fill-in flow,” which was only illustrated in their Figure 2 (1), because such a fill-in flow may be a slight “pit” and does not necessarily indicate a flow communicating to the closed LAA (Fig. 1B). Although the investigators should be congratulated for reporting on such a large cohort of patients who underwent LAA device closure, I found the LAA ostium length measurements biased and peri-device flow unconfirmed against the patients who had common peri-device flow (leak). These factors significantly impair the power of this study and put into question the accuracy of their conclusion. Jian-Fang Ren, MD* *Division of Cardiovascular Medicine University of Pennsylvania Health System 111 N 9th Street Philadelphia, Pennsylvania 19107 E-mail: [email protected] http://dx.doi.org/10.1016/j.jacc.2012.04.054
REFERENCES
1. Viles-Gonzalez JF, Kar S, Douglas P, et al. The clinical impact of incomplete left atrial appendage closure with the Watchman device in patients with atrial fibrillation: a PROTECT AF Substudy. J Am Coll Cardiol 2012;59:923–9. 2. Veinot JP, Harrity PJ, Gentile F, et al. Anatomy of the normal left atrial appendage: a quantitative study of age-related changes in 500 autopsy hearts: implications for echocardiographic examination. Circulation 1997;96:3112–5. 3. Ren JF, Callans DJ. Intracardiac echocardiography with different approaches for imaging of left atrial appendage (letter). Heart Rhythm 2006;3:623. 4. Hutchison MD, Callans DJ. Imaging the left atrial appendage with intracardiac echocardiography: leveling the playing field. Circ Arrhythm Electrophysiol 2010;3:564 –5.
Reply We read with interest the letter of Dr. Ren, stating that accurate echocardiographic measurement of the left atrial appendage (LAA) anatomy, especially of the ostium, is critically important for successful LAA ostial closure using the Watchman device. In our study, the Core Echocardiography Laboratory measured the echocardiographic ostium of the LAA, and the LAA body size (1). In addition, he expressed disagreement with the explanation of “shape mismatch,” which consists of an oval-shaped LAA and a spherical LAA closure device. We agree that accurate measurement of maximal LAA ostial diameter is of critical importance to obtain adequate seal of the LAA. We also share the opinion that the LAA ostium is a soft tissue structure that can be expanded and fit completely to the device shape if the device is placed at an optimal location. However, we found in clinical practice and during the study, that even when we chose a device that was slightly larger, because the diameter of the LAA ostium is larger in one of the orthogonal axes (i.e., oval shape), a spherical device may not
Correspondence
JACC Vol. 60, No. 15, 2012 October 9, 2012:1430–7
largest ski race, ongoing in Sweden since 1922, with a total of 926,350 participants through 2010. The last 10 years accounts for 45% of these skiers, with the addition of shorter distances as an option. During 90 years of ski racing, 20 cases (mean age 55 years) of CA occurred, 5 of which survived (mean age 47 years) the acute event. All cases were men, and had support of bystander cardiopulmonary resuscitation (CPR). Coronary heart disease was the cause of CA for 16 skiers. Two had hypertrophic cardiomyopathy, 1 had myocarditis, and 1 had ventricular fibrillation of unknown cause. The incidence proportion of CA was 2.16 per 100,000 skiers. The incidence rate was 0.31 per 100,000 skiing hours. The incidence rate was 0.46 per 100,000 racing hours in the last decade compared with 0.22 per 100,000 hours of skiing from 1922 to 2000. The mean distance until CA occurred was 25.7 ⫾ 15.8 km (95% confidence intervals [CI]: 6 to 45) for the survivors, and the distance for nonsurvivors was 33.6 ⫾ 29.8 km (95% CI: 17 to 50). The absolute risk of CA during the ski race is low. Nevertheless, the relative risk seems to be much higher than expected, considering the incidence in the race (4,030 per 100,000 person-years of skiing in the last decade) compared with the normal out-ofhospital CA rate (range, 13 to 52 by region per 100,000 personyears in recent years) in the general Swedish population (3). The risk for CA with the vigorous physical activity was very similar to long-distance running (1.01 per 100,000 for runners) and skiing (1). However, the timing of the occurrence was different. Although CA occurred mainly during the last quarter for runners, it occurred mainly in the first third of the ski race. This may indicate different trigger mechanisms for the induction of CA in different temperatures (2). A striking similarity between the running and the ski races was that the fatality rates were 75% and 71%, respectively, despite the 10-year higher mean age of the skiers. The possibility of survival is probably dependent of the active efforts of bystander CPR. The incidence rate in Vasaloppet has increased in the last decade, which may result from participation of less-trained people due to a greater public interest in exercise. It is important that the organizers of this kind of sporting event take responsibility for healthcare and rescue activities (4). Considering the relatively low absolute risk of CA, we are, however, convinced that the overall benefit of regular physical activity to public health is much larger than the risk of CA (5). *Ulf Hållmarker, MD Karl Michaëlsson, MD, PhD ¨ rnlöv, MD, PhD Johan A Stefan James, MD, PhD *Mora Lasarett Department of Internal Medicine, Department of Medical Science Uppsala University 792 85 Mora Sweden E-mail: [email protected] http://dx.doi.org/10.1016/j.jacc.2012.05.046 Please note: Dr. James has received institutional grants from AstraZeneca, Eli Lilly, BMS, Terumo Inc., Medtronic, and Vascular Solutions; and honoraria from AstraZeneca, Eli Lilly, Merck, Sanofi, and Abbott Vascular. All other author have reported that they have no relationships relevant to the contents of this paper to disclose.
REFERENCES
1. Kim Jonathan H, Rajeev M, et al. Cardiac arrest during long-distance running races. N Engl J Med 2012;366:130 – 40. 2. Bhaskaran K, Hajat S, Haines A, Herrett E, Wilkinson P, Smeeth L. Effects of ambient temperature on the incidence of myocardial infarction. Heart 2009;95:1760 –9. 3. Stromsoe A, Svensson L, Claesson A, Lindkvist J, Lundstrom A, Herlitz J. Association between population density and reported incidence, characteristics and outcome after out-of-hospital cardiac arrest in Sweden. Resuscitation 2011;82:1307–13. 4. Hållmarker U, Aronson D, Jansson A, Hamraeus K, Sjögren I. Cardiac arrest in the tracks of the forefathers (Hjärtstopp i fädrens spår Vasaloppet 2010). Läkartidningen 2010;107:2720 –2. 5. Fahramand BY, Ahlbom A, Ekblom Ö, et al. Mortality amongst participants in Vasaloppet: a classical long-distance ski race in Sweden. J Intern Med 2003;253:276 – 83.
Letters to the Editor
Accurate Echocardiographic Assessment of Left Atrial Appendage Ostium and Peri-Device Flow in Device Closure I read with interest the report by Viles-Gonzalez et al. (1), which indicated that residual peri-device flow into the left atrial appendage (LAA) after percutaneous closure with the Watchman device was common, and not associated with an increased risk of thromboembolism. Transesophageal echocardiography (TEE) was performed, and follow-up revealed that 32% of implanted patients had at least some degree of peri-device flow (“leak”) at 12 months. Although such observations are unique with a large sample available from the PROTECT AF (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial, the methodology and analytical data used to reach conclusions regarding risk of thromboembolism warrant further discussion. Accurate echocardiographic measurement of the LAA anatomy, especially of the ostium, is critically important for successful LAA ostial closure using the Watchman device. The echocardiographic ostium of the LAA, which is usually measured from the junction of the upper left pulmonary vein entering the LA to the junction of the LA and LAA, is somewhat larger than the anatomic ostium (2). The maximal LAA ostial diameter can be obtained and used as an accurate reference for LAA ostial diameter measured at baseline from TEE or intracardiac echocardiographic (ICE) LAA imaging views (3,4) (Fig. 1A). Viles-Gonzalez et al. (1) indicated that “there was a wide variation on the size of the LAA ostium width and length at baseline” and reported that “the mean LAA ostium width at baseline was 21.9 ⫾ 4.1 mm. . .The mean ostium length at baseline was 49.4 ⫾ 9.1 mm.” Obviously, such a large ostium length could not exist even in patients with atrial fibrillation (AF) and would be impossible to close with the largest Watchman device (33 mm). However, these LAA diameters are comparable with our measurements of the maximal short (18 ⫾ 4 mm) and long (50 ⫾ 9 mm) axes of LAA
Correspondence
JACC Vol. 60, No. 15, 2012 October 9, 2012:1430–7
Figure 1
1433
Intracardiac Echocardiographic Imaging of Left Atrial (LA) Appendage (LAA)
(A) The transducer is placed in the right ventricular outflow tract, showing the LAA ostium (Os; diameter ⫽ 18 mm, between the two white horizontal arrows) and the Watchman device (struts, arrows) located at the LAA Os, (B) The transducer is placed in the pulmonary artery (PA), showing the closure device (arrows) properly located at the LAA Os without peri-device flow seen around the LAA Os side. A blue color flow image in the LA side only indicates a slight “pit” region. Ao ⫽ aortic root; ulpv ⫽ upper left pulmonary vein.
body size in patients with AF (n ⫽ 42) using ICE imaging. The question is whether they measured the LAA ostium or just the LAA body size. Regarding peri-device flow (leak), Viles-Gonzalez et al. (1) explained that a peri-device flow would be the mismatch between the circular device and the typically oval LAA orifice and the subsequent inadequacy of circumferential LAA sealing. I disagree with this explanation of “shape mismatch” conception. Accurate measurement of maximal LAA ostial diameter is much more important than shape, because the LAA ostium is mainly a soft tissue structure that can be expanded and fit completely to the device shape if the device is placed at an optimal location. ICE LAA ostium imaging with color Doppler flow can reliably confirm the optimal location without any peri-device flow. Of note, to evaluate the peri-device flow (leak), LAA emptying flow is more important than the “fill-in flow,” which was only illustrated in their Figure 2 (1), because such a fill-in flow may be a slight “pit” and does not necessarily indicate a flow communicating to the closed LAA (Fig. 1B). Although the investigators should be congratulated for reporting on such a large cohort of patients who underwent LAA device closure, I found the LAA ostium length measurements biased and peri-device flow unconfirmed against the patients who had common peri-device flow (leak). These factors significantly impair the power of this study and put into question the accuracy of their conclusion. Jian-Fang Ren, MD* *Division of Cardiovascular Medicine University of Pennsylvania Health System 111 N 9th Street Philadelphia, Pennsylvania 19107 E-mail: [email protected] http://dx.doi.org/10.1016/j.jacc.2012.04.054
REFERENCES
1. Viles-Gonzalez JF, Kar S, Douglas P, et al. The clinical impact of incomplete left atrial appendage closure with the Watchman device in patients with atrial fibrillation: a PROTECT AF Substudy. J Am Coll Cardiol 2012;59:923–9. 2. Veinot JP, Harrity PJ, Gentile F, et al. Anatomy of the normal left atrial appendage: a quantitative study of age-related changes in 500 autopsy hearts: implications for echocardiographic examination. Circulation 1997;96:3112–5. 3. Ren JF, Callans DJ. Intracardiac echocardiography with different approaches for imaging of left atrial appendage (letter). Heart Rhythm 2006;3:623. 4. Hutchison MD, Callans DJ. Imaging the left atrial appendage with intracardiac echocardiography: leveling the playing field. Circ Arrhythm Electrophysiol 2010;3:564 –5.
Reply We read with interest the letter of Dr. Ren, stating that accurate echocardiographic measurement of the left atrial appendage (LAA) anatomy, especially of the ostium, is critically important for successful LAA ostial closure using the Watchman device. In our study, the Core Echocardiography Laboratory measured the echocardiographic ostium of the LAA, and the LAA body size (1). In addition, he expressed disagreement with the explanation of “shape mismatch,” which consists of an oval-shaped LAA and a spherical LAA closure device. We agree that accurate measurement of maximal LAA ostial diameter is of critical importance to obtain adequate seal of the LAA. We also share the opinion that the LAA ostium is a soft tissue structure that can be expanded and fit completely to the device shape if the device is placed at an optimal location. However, we found in clinical practice and during the study, that even when we chose a device that was slightly larger, because the diameter of the LAA ostium is larger in one of the orthogonal axes (i.e., oval shape), a spherical device may not