EDITORIAL
Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp
UltraSound of Silence Abdominal Aortic Aneurysm – A Milestone Evidence in Japanese Hypertensive Elderly Has Come Out – Yasuko K. Bando, MD, PhD; Toyoaki Murohara, MD, PhD
A
bdominal aortic aneurysm (AAA) is known as a “silent killer” because it potentially grows year by year and its outcome becomes more lethal once it has grown larger in size.1 The clinical definition of AAA is commonly that the maximum short-axis diameter at infrarenal measurement (taken below the renal artery branches) exceeds 30 mm.2 Another definition of AAA is also in use, whereby AAA is defined as at least a 50% increase in diameter compared with the expected normal diameter of the aorta.3 Patients with aneurysms >55 mm in diameter are generally considered for elective surgical repair,2,3 because mortality significantly drops once the AAA is >55 mm.1,2 The only consensus for radical intervention is surgical repair, but recently, endovascular aneurysm repair (EVAR) gives surgeons an alternative and less invasive therapeutic option.4 Patients with aneurysmal diameters ≤55 mm (termed smaller AAA [smAAA]) are managed with aneurysm
surveillance because previous evidence revealed that immediate surgical intervention for smAAA had no advantage compared with surveillance (UKSAT and ADAM trials).5–7
Article p 524 Likewise, regarding the advantage of EVAR for smAAA, clinical trials (CAESAR and PIVOTAL) found no advantage of EVAR for smAAA when compared with surveillance.8 Thus, an unsolved concern is how physicians should manage the preoperative smAAA because currently there is little highquality evidence or guidelines worldwide.3,5 It seems a more urgent issue to be solved in our region is that the clinical characteristics of AAA remain uncertain, particularly in Asians, including Japanese. In this issue of the Journal, Fukuda et al9 report milestone evidence in elderly
Figure. Variety of pocket-sized portable echo equipment (illustrations from the merchandise brochures published by the corresponding manufacturers). (A) Vscan1.2 (GE Healthcare Inc) used in the present study; (B) SONIMAGE P3 (Konica-Minolta Healthcare Inc); (C) ACUSON P10 (Nihon-Koden Inc and Simens Japan Inc), showing typical image when operating the portable echo (D).
The opinions expressed in this article are not necessarily those of the editors or of the Japanese Circulation Society. Received January 19, 2015; accepted January 19, 2015; released online February 2, 2015 Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan Mailing address: Yasuko K. Bando, MD, PhD or Toyoaki Murohara, MD, PhD, Department of Cardiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. E-mail: [email protected] or murohara@med. nagoya-u.ac.jp ISSN-1346-9843 doi: 10.1253/circj.CJ-15-0081 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: [email protected] Circulation Journal Vol.79, March 2015
504
BANDO YK et al.
Table. Prevalence of AAA According to Previous Clinical Studies AAA-Japan9 Age (years)
Comments
UK14
USA7
Sweden15
>60
65–79
>65
50–79
65
4.1% (69/1,731)
5–10%
1.5–4.6% (2,412/50,130)
2.1% (1,031/73,451)
2.2% (480/22,304)
Ultrasound (pocket echo)
Ultrasound and CT
Ultrasound
Ultrasound
Ultrasound
All patients had comorbid hypertension In patients >80 years old, AAA prevalence was higher (9.7% for males, 5.7% for females)9
4.1–14.2% in men and 0.35– 6.2% in women
5% in men and ≈one-third of this in women14
revalence of AAA % P (AAA/total patients) Measurement
Meta-analysis13
ADAM trial
Only males and limited to 65 years of age
AAA, abdominal aortic aneurysm.
Japanese patients with hypertension regarding the uncertain milieu of the asymptomatic AAA. This “AAA Japan study” was designed as a multicenter prospective observational study for assessment of the incidence of occult AAA in elderly hypertensive patients using the “pocket echo” (Figure). The total number registered reached 1,731 patients with hypertension aged >60 years, and the prevalence of AAA was 4.1%.3 Prior to measurement by pocket echo, the protocol required abdominal palpation. Readers will recall the importance of physical examination as an important basis for cardiologists to diagnose silent AAA. However, this study urged caution regarding AAA screening by palpation because the diagnostic sensitivity by abdominal palpation was found to be low (52%). It is noteworthy that if the size of the AAA was large enough (>40 mm), the sensitivity rose up to 75%. The diameter of the aorta measured by ultrasound is known to vary from the original size. One of the causes is coexisting kinking, as well as anatomical variations of the aorta, which leads to overestimation.10 It would have been beneficial if comparable CT assessment had been performed in the present study (but of course, that was impractical). To overcome this potential weakness, in the present study the reproducibility of the ultrasound measurements in terms of the interobserver variability in 15 subjects was carefully assessed by 2 independent blinded observers who were one of the trial investigators (H.W.) and an independent participant (K.S.). Furthermore, intraobserver variability was analyzed in another group of 15 subjects by the same observer (K.S.) at 2 different time points. The results found excellent correlation with the interobserver (r=0.98) and intraobserver (r=0.99) measurements. Collectively, the AAA Japan study demonstrated that AAA is not rare in the Japanese population with atherosclerotic risks, such as aging, hypertension, and familial history. Clinical evidence regarding AAA is more concrete and extensive in Western countries. The Cochrane annual report anticipates that there will be an increasing number of AAA cases if more patients are screened.3 More concrete numbers and details are displayed in Table. Aneurysms >55 mm (50 mm in the Japanese guideline) in the maximum short-axis diameter carry a high risk of rupture, and rupture carries a high risk of death. The original meaning of the song “The Sound of Silence” by Simon and Garfunkel was the inability of people to communicate with each other. To break the “silence”, some positive action is essential. The present study suggests the essential role of positive survey of the overlooked/silent AAA by palpation and ultrasound in the patient population at risk of atherosclerosis. An advanced and nationwide strategy has already begun in England. The national screening program for AAA (The NHS Screening Programmes) is organized as a part of Public Health England and an executive agency of the Depart-
ment of Health also supports the UK National Screening Committee.11,12 This type of approach might be considered inorder to establish a higher quality clinical database regarding AAA in Japan and Asia more widely. References 1. Powell JT, Greenhalgh RM. Clinical practice: Small abdominal aortic aneurysms. N Engl J Med 2003; 348: 1895 – 1901. 2. JCS Joint Working Group. Guidelines for diagnosis and treatment of aortic aneurysm and aortic dissection (JCS 2011): Digest version. Circ J 2013; 77: 789 – 828. 3. Rughani G, Robertson L, Clarke M. Medical treatment for small abdominal aortic aneurysms. Cochrane Database Syst Rev 2012; 9: CD009536. 4. Handa N, Yamashita M, Takahashi T, Onohara T, Okamoto M, Yamamoto T, et al. Impact of introducing endovascular aneurysm repair on treatment strategy for repair of abdominal aortic aneurysm: National Hospital Organization network study in Japan. Circ J 2014; 78: 1104 – 1111. 5. Kurosawa K, Matsumura JS, Yamanouchi D. Current status of medical treatment for abdominal aortic aneurysm. Circ J 2013; 77: 2860 – 2866. 6. United Kingdom Small Aneurysm Trial Participants. Long-term outcomes of immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002; 346: 1445 – 1452. 7. Lederle FA, Wilson SE, Johnson GR, Reinke DB, Littooy FN, Acher CW, et al. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002; 346: 1437 – 1444. 8. Ouriel K, Clair DG, Kent KC, Zarins CK. positive impact of endovascular options for treating aneurysms early. I: Endovascular repair compared with surveillance for patients with small abdominal aortic aneurysms. J Vasc Surg 2010; 51: 1081 – 1087. 9. Fukuda S, Watanabe H, Iwakura K, Daimon M, Ito H, Yoshikawa J; for the AAA Japan Study Investigators. Multicenter Investigations of the prevalence of abdominal aortic aneurysm in elderly Japanese patients with hypertension: The AAA Japan Study. Circ J 2015; 79: 524 – 529. 10. Akai A, Watanabe Y, Hoshina K, Obitsu Y, Deguchi J, Sato O, et al. Family history of aortic aneurysm is an independent risk factor for more rapid growth of small abdominal aortic aneurysms in Japan. J Vasc Surg 2015; 61: 287 – 290. 11. The NHS Abdominal Aortic Aneurysm Screening Programme Annual Report 2009–2010. http://aaa.screening.nhs.uk/annual_ report (accessed September 26, 2011). 12. Choke E, Vijaynagar B, Thompson J, Nasim A, Bown MJ, Sayers RD. Changing epidemiology of abdominal aortic aneurysms in England and Wales: Older and more benign? Circulation 2012; 125: 1617 – 1625. 13. Cosford PA, Leng GC. Screening for abdominal aortic aneurysm. Cochrane Database Syst Rev 2007; 2: CD002945. 14. Anjum A, Powell JT. Is the incidence of abdominal aortic aneurysm declining in the 21st century? Mortality and hospital admissions for England and Wales and Scotland. Eur J Vasc Endovasc Surg 2012; 43: 161 – 166. 15. Svensjo S, Bjorck M, Gurtelschmid M, Djavani Gidlund K, Hellberg A, Wanhainen A. Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease. Circulation 2011; 124: 1118 – 1123.
Circulation Journal Vol.79, March 2015
Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp
UltraSound of Silence Abdominal Aortic Aneurysm – A Milestone Evidence in Japanese Hypertensive Elderly Has Come Out – Yasuko K. Bando, MD, PhD; Toyoaki Murohara, MD, PhD
A
bdominal aortic aneurysm (AAA) is known as a “silent killer” because it potentially grows year by year and its outcome becomes more lethal once it has grown larger in size.1 The clinical definition of AAA is commonly that the maximum short-axis diameter at infrarenal measurement (taken below the renal artery branches) exceeds 30 mm.2 Another definition of AAA is also in use, whereby AAA is defined as at least a 50% increase in diameter compared with the expected normal diameter of the aorta.3 Patients with aneurysms >55 mm in diameter are generally considered for elective surgical repair,2,3 because mortality significantly drops once the AAA is >55 mm.1,2 The only consensus for radical intervention is surgical repair, but recently, endovascular aneurysm repair (EVAR) gives surgeons an alternative and less invasive therapeutic option.4 Patients with aneurysmal diameters ≤55 mm (termed smaller AAA [smAAA]) are managed with aneurysm
surveillance because previous evidence revealed that immediate surgical intervention for smAAA had no advantage compared with surveillance (UKSAT and ADAM trials).5–7
Article p 524 Likewise, regarding the advantage of EVAR for smAAA, clinical trials (CAESAR and PIVOTAL) found no advantage of EVAR for smAAA when compared with surveillance.8 Thus, an unsolved concern is how physicians should manage the preoperative smAAA because currently there is little highquality evidence or guidelines worldwide.3,5 It seems a more urgent issue to be solved in our region is that the clinical characteristics of AAA remain uncertain, particularly in Asians, including Japanese. In this issue of the Journal, Fukuda et al9 report milestone evidence in elderly
Figure. Variety of pocket-sized portable echo equipment (illustrations from the merchandise brochures published by the corresponding manufacturers). (A) Vscan1.2 (GE Healthcare Inc) used in the present study; (B) SONIMAGE P3 (Konica-Minolta Healthcare Inc); (C) ACUSON P10 (Nihon-Koden Inc and Simens Japan Inc), showing typical image when operating the portable echo (D).
The opinions expressed in this article are not necessarily those of the editors or of the Japanese Circulation Society. Received January 19, 2015; accepted January 19, 2015; released online February 2, 2015 Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan Mailing address: Yasuko K. Bando, MD, PhD or Toyoaki Murohara, MD, PhD, Department of Cardiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. E-mail: [email protected] or murohara@med. nagoya-u.ac.jp ISSN-1346-9843 doi: 10.1253/circj.CJ-15-0081 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: [email protected] Circulation Journal Vol.79, March 2015
504
BANDO YK et al.
Table. Prevalence of AAA According to Previous Clinical Studies AAA-Japan9 Age (years)
Comments
UK14
USA7
Sweden15
>60
65–79
>65
50–79
65
4.1% (69/1,731)
5–10%
1.5–4.6% (2,412/50,130)
2.1% (1,031/73,451)
2.2% (480/22,304)
Ultrasound (pocket echo)
Ultrasound and CT
Ultrasound
Ultrasound
Ultrasound
All patients had comorbid hypertension In patients >80 years old, AAA prevalence was higher (9.7% for males, 5.7% for females)9
4.1–14.2% in men and 0.35– 6.2% in women
5% in men and ≈one-third of this in women14
revalence of AAA % P (AAA/total patients) Measurement
Meta-analysis13
ADAM trial
Only males and limited to 65 years of age
AAA, abdominal aortic aneurysm.
Japanese patients with hypertension regarding the uncertain milieu of the asymptomatic AAA. This “AAA Japan study” was designed as a multicenter prospective observational study for assessment of the incidence of occult AAA in elderly hypertensive patients using the “pocket echo” (Figure). The total number registered reached 1,731 patients with hypertension aged >60 years, and the prevalence of AAA was 4.1%.3 Prior to measurement by pocket echo, the protocol required abdominal palpation. Readers will recall the importance of physical examination as an important basis for cardiologists to diagnose silent AAA. However, this study urged caution regarding AAA screening by palpation because the diagnostic sensitivity by abdominal palpation was found to be low (52%). It is noteworthy that if the size of the AAA was large enough (>40 mm), the sensitivity rose up to 75%. The diameter of the aorta measured by ultrasound is known to vary from the original size. One of the causes is coexisting kinking, as well as anatomical variations of the aorta, which leads to overestimation.10 It would have been beneficial if comparable CT assessment had been performed in the present study (but of course, that was impractical). To overcome this potential weakness, in the present study the reproducibility of the ultrasound measurements in terms of the interobserver variability in 15 subjects was carefully assessed by 2 independent blinded observers who were one of the trial investigators (H.W.) and an independent participant (K.S.). Furthermore, intraobserver variability was analyzed in another group of 15 subjects by the same observer (K.S.) at 2 different time points. The results found excellent correlation with the interobserver (r=0.98) and intraobserver (r=0.99) measurements. Collectively, the AAA Japan study demonstrated that AAA is not rare in the Japanese population with atherosclerotic risks, such as aging, hypertension, and familial history. Clinical evidence regarding AAA is more concrete and extensive in Western countries. The Cochrane annual report anticipates that there will be an increasing number of AAA cases if more patients are screened.3 More concrete numbers and details are displayed in Table. Aneurysms >55 mm (50 mm in the Japanese guideline) in the maximum short-axis diameter carry a high risk of rupture, and rupture carries a high risk of death. The original meaning of the song “The Sound of Silence” by Simon and Garfunkel was the inability of people to communicate with each other. To break the “silence”, some positive action is essential. The present study suggests the essential role of positive survey of the overlooked/silent AAA by palpation and ultrasound in the patient population at risk of atherosclerosis. An advanced and nationwide strategy has already begun in England. The national screening program for AAA (The NHS Screening Programmes) is organized as a part of Public Health England and an executive agency of the Depart-
ment of Health also supports the UK National Screening Committee.11,12 This type of approach might be considered inorder to establish a higher quality clinical database regarding AAA in Japan and Asia more widely. References 1. Powell JT, Greenhalgh RM. Clinical practice: Small abdominal aortic aneurysms. N Engl J Med 2003; 348: 1895 – 1901. 2. JCS Joint Working Group. Guidelines for diagnosis and treatment of aortic aneurysm and aortic dissection (JCS 2011): Digest version. Circ J 2013; 77: 789 – 828. 3. Rughani G, Robertson L, Clarke M. Medical treatment for small abdominal aortic aneurysms. Cochrane Database Syst Rev 2012; 9: CD009536. 4. Handa N, Yamashita M, Takahashi T, Onohara T, Okamoto M, Yamamoto T, et al. Impact of introducing endovascular aneurysm repair on treatment strategy for repair of abdominal aortic aneurysm: National Hospital Organization network study in Japan. Circ J 2014; 78: 1104 – 1111. 5. Kurosawa K, Matsumura JS, Yamanouchi D. Current status of medical treatment for abdominal aortic aneurysm. Circ J 2013; 77: 2860 – 2866. 6. United Kingdom Small Aneurysm Trial Participants. Long-term outcomes of immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002; 346: 1445 – 1452. 7. Lederle FA, Wilson SE, Johnson GR, Reinke DB, Littooy FN, Acher CW, et al. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002; 346: 1437 – 1444. 8. Ouriel K, Clair DG, Kent KC, Zarins CK. positive impact of endovascular options for treating aneurysms early. I: Endovascular repair compared with surveillance for patients with small abdominal aortic aneurysms. J Vasc Surg 2010; 51: 1081 – 1087. 9. Fukuda S, Watanabe H, Iwakura K, Daimon M, Ito H, Yoshikawa J; for the AAA Japan Study Investigators. Multicenter Investigations of the prevalence of abdominal aortic aneurysm in elderly Japanese patients with hypertension: The AAA Japan Study. Circ J 2015; 79: 524 – 529. 10. Akai A, Watanabe Y, Hoshina K, Obitsu Y, Deguchi J, Sato O, et al. Family history of aortic aneurysm is an independent risk factor for more rapid growth of small abdominal aortic aneurysms in Japan. J Vasc Surg 2015; 61: 287 – 290. 11. The NHS Abdominal Aortic Aneurysm Screening Programme Annual Report 2009–2010. http://aaa.screening.nhs.uk/annual_ report (accessed September 26, 2011). 12. Choke E, Vijaynagar B, Thompson J, Nasim A, Bown MJ, Sayers RD. Changing epidemiology of abdominal aortic aneurysms in England and Wales: Older and more benign? Circulation 2012; 125: 1617 – 1625. 13. Cosford PA, Leng GC. Screening for abdominal aortic aneurysm. Cochrane Database Syst Rev 2007; 2: CD002945. 14. Anjum A, Powell JT. Is the incidence of abdominal aortic aneurysm declining in the 21st century? Mortality and hospital admissions for England and Wales and Scotland. Eur J Vasc Endovasc Surg 2012; 43: 161 – 166. 15. Svensjo S, Bjorck M, Gurtelschmid M, Djavani Gidlund K, Hellberg A, Wanhainen A. Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease. Circulation 2011; 124: 1118 – 1123.
Circulation Journal Vol.79, March 2015
