Epidemiology of sudden cardiac death: clinical and research implications

Abstract

The current annual incidence of sudden cardiac death in the United States is likely to be in the range of 180,000 to 250,000 per year. Coinciding with the decreased mortality from coronary artery disease, there is evidence pointing toward a significant decrease in rates of sudden cardiac death in the United States during the second half of the 20th century. However, the alarming rise in prevalence of obesity and diabetes in the first decade of the new millennium both in the United States and worldwide, would indicate that this favorable trend is unlikely to persist. We are likely to witness a resurgence of coronary artery disease and heart failure, as a result of which sudden cardiac death will have to be confronted as a shared and indiscriminate, worldwide public health problem. There is also increasing recognition of the fact that discovery of meaningful and relevant risk stratification and prevention methodologies will require careful prospective community-wide analyses, with access to large archives of DNA, serum, and tissue that link with well-phenotyped databases. The purpose of this review is to summarize current knowledge of sudden cardiac death epidemiology. We will discuss the significance and strengths of community-wide evaluations of sudden cardiac death, summarize recent observations from such studies, and finally highlight specific potential predictors that warrant further evaluation as determinants of sudden cardiac death in the general population.

Figure 1

The Oregon Sudden Unexpected Death Study: A prospective, population-based multiple-source evaluation of sudden cardiac arrest, ongoing since Feb 1, 2002.

Figure 2

Age-based annual incidence of sudden cardiac death among residents of Multnomah County, Oregon (population 660,486). From Chugh SS, Jui J, Gunson K, Stecker EC, John BT, Thompson B, Ilias N, Vickers C, Dogra V, Daya M, Kron J, Zheng ZJ, Mensah G, McAnulty J. Current burden of sudden cardiac death: multiple source surveillance versus retrospective death certificate-based review in a large U.S. community. J Am Coll Cardiol 2004;44(6):1268–75. Reprinted by permission of the American College of Cardiology Foundation ©2004.

Figure 3

Gender- and age-based composition of prospectively determined sudden cardiac death population. Adapted from Chugh SS, Jui J, Gunson K, Stecker EC, John BT, Thompson B, Ilias N, Vickers C, Dogra V, Daya M, Kron J, Zheng ZJ, Mensah G, McAnulty J. Current burden of sudden cardiac death: multiple source surveillance versus retrospective death certificate-based review in a large U.S. community. J Am Coll Cardiol 2004;44(6):1268–75. Reprinted by permission of the American College of Cardiology Foundation ©2004.

Figure 4

Previously silent coronary artery disease is likely to be the predominant disease condition contributing to sudden cardiac death in the general population.

Figure 5

Sex-based distribution of presumed etiologies of sudden cardiac death. These data represent comparisons between 27 women and 45 men ages 35–44 years. CAD, Coronary artery disease; CA, coronary artery; HCM, hypertrophic cardiomyopathy; WPW, Wolff-Parkinson-White syndrome; ARVD, arrhythmogenic right ventricular dysplasia; CHD, congenital heart disease. Adapted from Chugh SS, Chung K, Zheng ZJ, John B, Titus JL. Cardiac pathologic findings reveal a high rate of sudden cardiac death of undetermined etiology in younger women. Am Heart J 2003;146(4):635–9. Reprinted by permission of Mosby Inc. ©2003.

Figure 6

Severe LV dysfunction, currently the risk predictor most widely used in clinical practice, is likely to affect less than a third of all cases of sudden cardiac death in the general population.

Figure 7

Annual incidence of sudden cardiac arrest based on address of residence in Multnomah County, in census tracts grouped by quartiles of socioeconomic status (SES), low SES to high SES. (A) All ages combined; (B) age 0—64 years; (C) age 65 years and older. Adapted from Reinier K, Stecker EC, Vickers C, Gunson K, Jui J, Chugh SS. Incidence of sudden cardiac arrest is higher in areas of low socioeconomic status: A prospective two year study in a large United States community. Resuscitation 2006;70(2):186–92. Reprinted with permission from Elsevier Ireland Ltd. ©2006.

Figure 7

Annual incidence of sudden cardiac arrest based on address of residence in Multnomah County, in census tracts grouped by quartiles of socioeconomic status (SES), low SES to high SES. (A) All ages combined; (B) age 0—64 years; (C) age 65 years and older. Adapted from Reinier K, Stecker EC, Vickers C, Gunson K, Jui J, Chugh SS. Incidence of sudden cardiac arrest is higher in areas of low socioeconomic status: A prospective two year study in a large United States community. Resuscitation 2006;70(2):186–92. Reprinted with permission from Elsevier Ireland Ltd. ©2006.

Figure 8

Sudden cardiac death is a complex phenotype and determinants are likely to be multi-factorial. There appears to be a significant genetic component which has to considered in the context of multiple cardiac conditions, co-morbidities as well as epidemiologic and environmental factors.