JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
VOL. 67, NO. 5, 2016
ª 2016 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
ISSN 0735-1097/$36.00
PUBLISHED BY ELSEVIER
http://dx.doi.org/10.1016/j.jacc.2015.12.011
GUEST EDITOR’S PAGE
Sudden Cardiac Death in Asia and China Are We Different? Ngai-Yin Chan, MBBS, FRCP, FACC, FHRS
S
udden cardiac death (SCD) is both a major clin-
2005 to 2006 in China (7). A total of 678,718 in-
ical condition and a public problem claiming
habitants were monitored for 1 year, and 284 SCDs
>3.7 million lives worldwide each year (1).
occurred. The overall incidence of SCD was 41.8 per
The causes and prevalence of SCD are dependent on
100,000 people. A retrospective study on the inci-
age, sex, ethnicity, and genetics (2). Although there
dence of SCD was performed in Japan by reviewing
is a wealth of data on SCD from Western countries,
the death certificates, hospital records, forensic
data from Asia and China are relatively scarce. Thus,
medical records, and police records of the residents of
there has been controversy on the potentially lower
the southern part of Okinawa island (8). A total of 126
prevalence of and propensity for SCD in Asians. On
residents died suddenly during a 3-year period from
the basis of U.S. Vital Statistics data in 1998, the SCD
1992 to 1994, giving a crude incidence rate of 37 per
death rates (per 100,000) were 503, 407, 259, and 213
100,000/year. In Hong Kong, a retrospective review
for the black, white, American Indian/Alaskan native,
of the coroners’ reports revealed a very low incidence
and Asian/Pacific Islander populations, respectively
rate of 1.8 sudden deaths per 100,000 people in 1997
(3). In addition, in the State of Hawaii, Asian ancestry
(9). Compared with the data from United States, the
groups had a much lower cardiovascular mortality
incidence of SCD in Asians appears to be lower. In a
than Hawaiians and Caucasians (4). This controversy,
retrospective analysis of death certificates from the
together with the socioeconomics of Asian countries,
National Mortality Followback Survey, 18,733 deaths
has resulted in a wide gap in adopting implantable
were included in the study (10). An incidence of 176
cardioverter-defibrillator (ICD) therapy for SCD pre-
and 85 per 100,000 people for SCD was observed for
vention
In
men and women, respectively. In a prospective
2009, the ICD implantation rate in the United States
evaluation among 660,486 residents of Multnomah
was 434 per million people (5). Although there has
County, Oregon, using multiple sources of surveil-
been a rising trend of ICD implantation rates in Asia,
lance, an SCD incidence rate of 53 per 100,000 people
the numbers still lagged behind and varied from
was observed (11).
compared
with
Western
countries.
0.4 in the Philippines, 1.4 in China to 50 in Japan, and 54.3 in Singapore per million people in 2013 (6).
SCD IN ISCHEMIC CARDIOMYOPATHY
The prevalence of SCD in different Asian countries and the specific conditions of ischemic cardiomyopa-
Ischemic cardiomyopathy with poor left ventricular
thy, hypertrophic cardiomyopathy (HCM), and Bru-
ejection fraction (LVEF) is an important cause of SCD
gada syndrome will be discussed in more detail.
(12). However, whether Asians with this condition
PREVALENCE OF SCD IN ASIA AND CHINA A prospective study on SCD incidence was performed in 4 regions with different socioeconomic status in
have a lower propensity for SCD compared with their Western counterparts remains controversial. In a retrospective study of 3,258 Japanese patients who underwent elective cardiac catheterization, 90 patients met the MADIT II (Multicenter Automatic Defibrillator Implantation Trial) criteria (13) with a
From the Department of Medicine & Geriatrics, Princess Margaret
history of Q-wave myocardial infarction over 40 days,
Hospital, Hong Kong.
LVEF #30%, and age >21 years, but did not undergo
Chan
JACC VOL. 67, NO. 5, 2016 FEBRUARY 9, 2016:590–2
Guest Editor’s Page
ICD implantation (14). The survival rate of these 90
annual mortality rate of 1.6% was observed, com-
patients was comparable to the MADIT II defibrillator
pared with 5.6% in non-Asians (19). The lower mor-
group but higher than the MADIT II conventional
tality rate in Chinese patients may be due to a
therapy group. These observations suggest a lower
difference in disease-causing mutations. The com-
propensity of Japanese patients for SCD. On the
mon malignant mutation of R403Q in MYH7 identi-
contrary, another retrospective study of 617 Chinese
fied in Caucasian patients was not detected in a study
patients from Hong Kong who were referred for car-
involving 34 Chinese patients with HCM (20).
diac rehabilitation showed the opposite results (15). A total of 70 patients met the MADIT II criteria but did
SCD IN BRUGADA SYNDROME
not undergo ICD implantation. The survival rate of these 70 patients was comparable to the MADIT II
The prevalence of Brugada syndrome is likely to be
conventional therapy group but lower than the
higher in Southeast Asia than in Europe and the
MADIT II defibrillator group. Potential explanations
United States. The prevalence rate was estimated to
for the discrepancy of results include a higher pro-
be 0.02% to 0.1% in Europe and 0.1% to 0.25% in Asia
portion of patients with New York Heart Association
(5). Despite a difference in prevalence, the event rates
functional class I status and coronary revasculariza-
in Asian patients appear to be similar to those of
tion in the Japanese study.
Westerners.
Socioeconomic status of many Asian countries limits the application of ICD therapy for primary prevention of SCD in ischemic cardiomyopathy. Further risk stratification may be appropriate to improve the cost-effectiveness of ICD therapy. In a prospective observational study, 1,018 Chinese patients who had LVEF #35%, New York Heart Association functional class II or III status, and >40 days after myocardial infarction did not undergo ICD implantation for various reasons (16). During a mean follow-up of 2.8 years, all-cause mortality was 7.4% and SCD was 5%. Independent predictors of SCD included older age, LVEF #25%, and absence of coronary revascularization.
ARE ASIANS DIFFERENT FROM WESTERNERS IN THE PREVALENCE OF AND PROPENSITY FOR SCD? A true comparison between different ethnicities in the prevalence of SCD has been limited by the difference in study methodologies, prevalence of cardiovascular risk factors, and underlying conditions. Despite the scarcity of data from Asian countries, prevalence of SCD appears to be lower than that of the Western counterparts. Although a difference in genetic mutation profile in Asians has been observed in some underlying conditions causing SCD, a difference in the propensity for SCD remains controversial. Further research in this area is eagerly and
SCD IN HCM
urgently awaited to guide more appropriate clinical The prevalence of HCM in China was 0.16%, which
decisions.
was comparable to the Western data, according to a population-based echocardiographic study on 8,080
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
Chinese adults (17). In another long-term follow-up
Ngai-Yin Chan, Room 223, Block J, Princess Margaret
study in Chinese patients from Hong Kong, a high
Hospital, 2-10 Princess Margaret Hospital Road, Lai
incidence of AF (35%) and nonobstructive apical hy-
Chi Kok, Kowloon, Hong Kong. E-mail: ngaiyinchan@
pertrophy (41%) were observed (18). However, a low
yahoo.com.hk.
REFERENCES 1. Mehra R. Global public health problem of sudden cardiac death. J Electrocardiol 2007;40 6 Suppl:S118–22.
5. Murakoshi N, Aonuma K. Epidemiology of arrhythmias and sudden cardiac death in Asia. Circ J 2013;77:2419–31.
2. Sung RJ, Kuo CT, Wu SN, et al. Sudden cardiac death syndrome: age, gender, ethnicity, and genetics. Acta Cardiol Sin 2008;24:65–74.
6. Zhang S, Lau CP, Nair M, et al. Asia Pacific Heart Rhythm Society White Book 2014. Available at: https://www.aphrs.org/attachments/article/42/APHRS %20White%20Book%202014.pdf. Accessed December 18, 2015.
3. Zheng ZJ, Croft JB, Giles WH, et al. Sudden cardiac death in the United States, 1989 to 1998. Circulation 2001;104:2158–63. 4. Office of Health Status Monitoring, Hawaii
7. Hua W, Zhang LF, Wu YF, et al. Incidence of sudden cardiac death in China: analysis of 4
Department of Health. Hawaii Health Survey 2001. Honolulu: Hawaii Department of Health, 2002.
regional populations. J Am Coll Cardiol 2009;54: 1110–8.
8. Tokashiki T, Muratani A, Kimura Y, et al. Sudden death in the general population in Okinawa: incidence and causes of death. Jpn Circ J 1999;63: 37–42. 9. Lee KL, Fan K, Lau CP. Sudden death in Hong Kong: are we naturally protected? J HK Coll Cardiol 1999;9:117–8. 10. Escobedo LG, Zack MM. Comparison of sudden and nonsudden coronary deaths in the United States. Circulation 1996;93:2033–6. 11. Chugh SS, Jui J, Gunson K, et al. Current burden of sudden cardiac death: multiple source
591
592
Chan
JACC VOL. 67, NO. 5, 2016 FEBRUARY 9, 2016:590–2
Guest Editor’s Page
surveillance versus retrospective death certificatebased review in a large US community. J Am Coll Cardiol 2004;44:1268–75. 12. Meta-analysis Global Group in Chronic Heart Failure (MAGGIC). The survival of patients with heart failure with preserved or reduced left
14. Tanno K, Miyoshi F, Watanabe N, et al. Are the MADIT II criteria for ICD implantation appropriate for Japanese patients? Circ J 2005; 69:19–22.
17. Zou Y, Song L, Wang Z, et al. Prevalence of idiopathic hypertrophic cardiomyopathy in China: a population-based echocardiographic analysis of 8080 adults. Am J Med 2004;116:14–8.
15. Siu CW, Pong V, Ho HH, et al. Are MADIT II criteria for implantable cardioverter defibril-
18. Ho HH, Lee KL, Lau CP, et al. Clinical charac-
ventricular ejection fraction: an individual patient data meta-analysis. Eur Heart J 2012;33: 1750–7.
lator implantation appropriate for Chinese patients? J Cardiovasc Electrophysiol 2010;21: 231–5.
13. Moss AJ, Zareba W, Hall WJ, et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med 2002;346:
16. Fan XH, Hua W, Xu YZ, et al. Incidence and predictors of sudden cardiac death in patients with reduced left ventricular ejection fraction after myocardial infarction in an era of revasculariza-
877–83.
tion. Heart 2014;100:1242–9.
teristics of and long-term outcome in Chinese patients with hypertrophic cardiomyopathy. Am J Med 2004;116:19–23. 19. Maron BJ. Hypertrophic cardiomyopathy: an important global disease. Am J Med 2004;116:63–5. 20. Song L, Zou Y, Wang J, et al. Mutations profile in Chinese patients with hypertrophic cardiomyopathy. Clin Chim Acta 2005;351:209–16.
VOL. 67, NO. 5, 2016
ª 2016 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
ISSN 0735-1097/$36.00
PUBLISHED BY ELSEVIER
http://dx.doi.org/10.1016/j.jacc.2015.12.011
GUEST EDITOR’S PAGE
Sudden Cardiac Death in Asia and China Are We Different? Ngai-Yin Chan, MBBS, FRCP, FACC, FHRS
S
udden cardiac death (SCD) is both a major clin-
2005 to 2006 in China (7). A total of 678,718 in-
ical condition and a public problem claiming
habitants were monitored for 1 year, and 284 SCDs
>3.7 million lives worldwide each year (1).
occurred. The overall incidence of SCD was 41.8 per
The causes and prevalence of SCD are dependent on
100,000 people. A retrospective study on the inci-
age, sex, ethnicity, and genetics (2). Although there
dence of SCD was performed in Japan by reviewing
is a wealth of data on SCD from Western countries,
the death certificates, hospital records, forensic
data from Asia and China are relatively scarce. Thus,
medical records, and police records of the residents of
there has been controversy on the potentially lower
the southern part of Okinawa island (8). A total of 126
prevalence of and propensity for SCD in Asians. On
residents died suddenly during a 3-year period from
the basis of U.S. Vital Statistics data in 1998, the SCD
1992 to 1994, giving a crude incidence rate of 37 per
death rates (per 100,000) were 503, 407, 259, and 213
100,000/year. In Hong Kong, a retrospective review
for the black, white, American Indian/Alaskan native,
of the coroners’ reports revealed a very low incidence
and Asian/Pacific Islander populations, respectively
rate of 1.8 sudden deaths per 100,000 people in 1997
(3). In addition, in the State of Hawaii, Asian ancestry
(9). Compared with the data from United States, the
groups had a much lower cardiovascular mortality
incidence of SCD in Asians appears to be lower. In a
than Hawaiians and Caucasians (4). This controversy,
retrospective analysis of death certificates from the
together with the socioeconomics of Asian countries,
National Mortality Followback Survey, 18,733 deaths
has resulted in a wide gap in adopting implantable
were included in the study (10). An incidence of 176
cardioverter-defibrillator (ICD) therapy for SCD pre-
and 85 per 100,000 people for SCD was observed for
vention
In
men and women, respectively. In a prospective
2009, the ICD implantation rate in the United States
evaluation among 660,486 residents of Multnomah
was 434 per million people (5). Although there has
County, Oregon, using multiple sources of surveil-
been a rising trend of ICD implantation rates in Asia,
lance, an SCD incidence rate of 53 per 100,000 people
the numbers still lagged behind and varied from
was observed (11).
compared
with
Western
countries.
0.4 in the Philippines, 1.4 in China to 50 in Japan, and 54.3 in Singapore per million people in 2013 (6).
SCD IN ISCHEMIC CARDIOMYOPATHY
The prevalence of SCD in different Asian countries and the specific conditions of ischemic cardiomyopa-
Ischemic cardiomyopathy with poor left ventricular
thy, hypertrophic cardiomyopathy (HCM), and Bru-
ejection fraction (LVEF) is an important cause of SCD
gada syndrome will be discussed in more detail.
(12). However, whether Asians with this condition
PREVALENCE OF SCD IN ASIA AND CHINA A prospective study on SCD incidence was performed in 4 regions with different socioeconomic status in
have a lower propensity for SCD compared with their Western counterparts remains controversial. In a retrospective study of 3,258 Japanese patients who underwent elective cardiac catheterization, 90 patients met the MADIT II (Multicenter Automatic Defibrillator Implantation Trial) criteria (13) with a
From the Department of Medicine & Geriatrics, Princess Margaret
history of Q-wave myocardial infarction over 40 days,
Hospital, Hong Kong.
LVEF #30%, and age >21 years, but did not undergo
Chan
JACC VOL. 67, NO. 5, 2016 FEBRUARY 9, 2016:590–2
Guest Editor’s Page
ICD implantation (14). The survival rate of these 90
annual mortality rate of 1.6% was observed, com-
patients was comparable to the MADIT II defibrillator
pared with 5.6% in non-Asians (19). The lower mor-
group but higher than the MADIT II conventional
tality rate in Chinese patients may be due to a
therapy group. These observations suggest a lower
difference in disease-causing mutations. The com-
propensity of Japanese patients for SCD. On the
mon malignant mutation of R403Q in MYH7 identi-
contrary, another retrospective study of 617 Chinese
fied in Caucasian patients was not detected in a study
patients from Hong Kong who were referred for car-
involving 34 Chinese patients with HCM (20).
diac rehabilitation showed the opposite results (15). A total of 70 patients met the MADIT II criteria but did
SCD IN BRUGADA SYNDROME
not undergo ICD implantation. The survival rate of these 70 patients was comparable to the MADIT II
The prevalence of Brugada syndrome is likely to be
conventional therapy group but lower than the
higher in Southeast Asia than in Europe and the
MADIT II defibrillator group. Potential explanations
United States. The prevalence rate was estimated to
for the discrepancy of results include a higher pro-
be 0.02% to 0.1% in Europe and 0.1% to 0.25% in Asia
portion of patients with New York Heart Association
(5). Despite a difference in prevalence, the event rates
functional class I status and coronary revasculariza-
in Asian patients appear to be similar to those of
tion in the Japanese study.
Westerners.
Socioeconomic status of many Asian countries limits the application of ICD therapy for primary prevention of SCD in ischemic cardiomyopathy. Further risk stratification may be appropriate to improve the cost-effectiveness of ICD therapy. In a prospective observational study, 1,018 Chinese patients who had LVEF #35%, New York Heart Association functional class II or III status, and >40 days after myocardial infarction did not undergo ICD implantation for various reasons (16). During a mean follow-up of 2.8 years, all-cause mortality was 7.4% and SCD was 5%. Independent predictors of SCD included older age, LVEF #25%, and absence of coronary revascularization.
ARE ASIANS DIFFERENT FROM WESTERNERS IN THE PREVALENCE OF AND PROPENSITY FOR SCD? A true comparison between different ethnicities in the prevalence of SCD has been limited by the difference in study methodologies, prevalence of cardiovascular risk factors, and underlying conditions. Despite the scarcity of data from Asian countries, prevalence of SCD appears to be lower than that of the Western counterparts. Although a difference in genetic mutation profile in Asians has been observed in some underlying conditions causing SCD, a difference in the propensity for SCD remains controversial. Further research in this area is eagerly and
SCD IN HCM
urgently awaited to guide more appropriate clinical The prevalence of HCM in China was 0.16%, which
decisions.
was comparable to the Western data, according to a population-based echocardiographic study on 8,080
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
Chinese adults (17). In another long-term follow-up
Ngai-Yin Chan, Room 223, Block J, Princess Margaret
study in Chinese patients from Hong Kong, a high
Hospital, 2-10 Princess Margaret Hospital Road, Lai
incidence of AF (35%) and nonobstructive apical hy-
Chi Kok, Kowloon, Hong Kong. E-mail: ngaiyinchan@
pertrophy (41%) were observed (18). However, a low
yahoo.com.hk.
REFERENCES 1. Mehra R. Global public health problem of sudden cardiac death. J Electrocardiol 2007;40 6 Suppl:S118–22.
5. Murakoshi N, Aonuma K. Epidemiology of arrhythmias and sudden cardiac death in Asia. Circ J 2013;77:2419–31.
2. Sung RJ, Kuo CT, Wu SN, et al. Sudden cardiac death syndrome: age, gender, ethnicity, and genetics. Acta Cardiol Sin 2008;24:65–74.
6. Zhang S, Lau CP, Nair M, et al. Asia Pacific Heart Rhythm Society White Book 2014. Available at: https://www.aphrs.org/attachments/article/42/APHRS %20White%20Book%202014.pdf. Accessed December 18, 2015.
3. Zheng ZJ, Croft JB, Giles WH, et al. Sudden cardiac death in the United States, 1989 to 1998. Circulation 2001;104:2158–63. 4. Office of Health Status Monitoring, Hawaii
7. Hua W, Zhang LF, Wu YF, et al. Incidence of sudden cardiac death in China: analysis of 4
Department of Health. Hawaii Health Survey 2001. Honolulu: Hawaii Department of Health, 2002.
regional populations. J Am Coll Cardiol 2009;54: 1110–8.
8. Tokashiki T, Muratani A, Kimura Y, et al. Sudden death in the general population in Okinawa: incidence and causes of death. Jpn Circ J 1999;63: 37–42. 9. Lee KL, Fan K, Lau CP. Sudden death in Hong Kong: are we naturally protected? J HK Coll Cardiol 1999;9:117–8. 10. Escobedo LG, Zack MM. Comparison of sudden and nonsudden coronary deaths in the United States. Circulation 1996;93:2033–6. 11. Chugh SS, Jui J, Gunson K, et al. Current burden of sudden cardiac death: multiple source
591
592
Chan
JACC VOL. 67, NO. 5, 2016 FEBRUARY 9, 2016:590–2
Guest Editor’s Page
surveillance versus retrospective death certificatebased review in a large US community. J Am Coll Cardiol 2004;44:1268–75. 12. Meta-analysis Global Group in Chronic Heart Failure (MAGGIC). The survival of patients with heart failure with preserved or reduced left
14. Tanno K, Miyoshi F, Watanabe N, et al. Are the MADIT II criteria for ICD implantation appropriate for Japanese patients? Circ J 2005; 69:19–22.
17. Zou Y, Song L, Wang Z, et al. Prevalence of idiopathic hypertrophic cardiomyopathy in China: a population-based echocardiographic analysis of 8080 adults. Am J Med 2004;116:14–8.
15. Siu CW, Pong V, Ho HH, et al. Are MADIT II criteria for implantable cardioverter defibril-
18. Ho HH, Lee KL, Lau CP, et al. Clinical charac-
ventricular ejection fraction: an individual patient data meta-analysis. Eur Heart J 2012;33: 1750–7.
lator implantation appropriate for Chinese patients? J Cardiovasc Electrophysiol 2010;21: 231–5.
13. Moss AJ, Zareba W, Hall WJ, et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med 2002;346:
16. Fan XH, Hua W, Xu YZ, et al. Incidence and predictors of sudden cardiac death in patients with reduced left ventricular ejection fraction after myocardial infarction in an era of revasculariza-
877–83.
tion. Heart 2014;100:1242–9.
teristics of and long-term outcome in Chinese patients with hypertrophic cardiomyopathy. Am J Med 2004;116:19–23. 19. Maron BJ. Hypertrophic cardiomyopathy: an important global disease. Am J Med 2004;116:63–5. 20. Song L, Zou Y, Wang J, et al. Mutations profile in Chinese patients with hypertrophic cardiomyopathy. Clin Chim Acta 2005;351:209–16.
