BMJ  2004;328:E275 (28 February), doi:10.1136/bmj.328.7438.E275

BMJ USA: Commentary

Sudden death

CardioVision 2020, Mayo Clinic College of Medicine Rochester, Minnesota tkottke{at}mayo.edu

Department of Medicine Mayo Clinic College of Medicine Rochester, Minnesota

What can primary care doctors do?

There is belief (p 45) that placing automated external defibrillators (AEDs) into the hands of trained first responders and untrained bystanders is the best way to reduce rates of sudden death.¹ However, trials conducted by van Alem et al (p 23) and others² have not succeeded in increasing survival rates. The National Heart, Lung, and Blood Institute-sponsored randomized trial testing the strategy of public access to AEDs was only marginally successful: The average intervention effect was one life saved in a community once every three years at a cost of training 800 volunteers and providing them with access to AEDs.³ Walker et al conclude that even under hypothetical conditions of effectiveness, public access to AEDs is not a cost effective use of resources (p 28).

Even giving AEDs to all myocardial infarction survivors would—at most—reduce population rates of sudden death by 5%. Only 50% of all victims of sudden death have a history of heart disease.⁴ At least 50% of sudden deaths occur when the victim is alone,⁵ and even when a bystander is present, long-term survival after cardiac arrest is 20% at best.⁶

On the other hand, there is evidence that a primary care physician can reduce sudden death by 30% or more by taking the following actions: Based on observational data:

• Advising and assisting all patients to quit smoking and to avoid environmental tobacco smoke. Smoking has been observed to double the risk of sudden death.
  
• Advising all patients to adopt a program of daily physical activity. Habitual physical activity has been observed to attenuate the risk of sudden death during vigorous physical activity.⁷
  

Based on trial data:

• Advising all patients to eat at least two servings of high-omega-3, low-mercury fish each week or to take 1000 mg of omega-3 fatty acid supplements each day.⁸
  
• Prescribing eplerenone for patients with hypertension complicated by left ventricular hypertrophy.⁹
  
• Prescribing spironolactone for patients with congestive heart failure or significant left ventricular dysfunction.¹⁰
  

Because a small change in risk among a large proportion of the population has a far greater impact than a large change in risk among a small proportion of the population,¹¹ it can be expected that the largest impact would be derived from increasing fish or fish oil consumption among all patients. The other interventions would be expected to reduce rates of sudden death by 20% to 30% among the patients who qualify for them.

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Competing interests: None declared.

References

1. Nichol G, Hallstrom AP, Kerber R, Moss AJ, Ornato JP, Palmer D, et al. American Heart Association report on the second public access defibrillation conference, April 17-19, 1997. Circulation 1998;97: 1309-1314.[Free Full Text]
2. Brown J, Kellerman AL. The shocking truth about automated external defibrillators. JAMA 2000;284: 1438-1441.[Free Full Text]
3. Public access defibrillation by trained community volunteers increases survival for victims of cardiac arrest. Bethesda, MD: National Heart, Lung, and Blood Institute. Press release. November 11, 2003. http://www.nih.gov/news/pr/nov2003/nhlbi-11.htm.
4. Goraya TY, Jacobsen SJ, Kottke TE, Frye RL, Weston SA, Roger VL. Coronary heart disease death and sudden cardiac death: a 20-year population-based study. Am J Epidemiol 2003;157: 763-770.[Abstract/Free Full Text]
5. Wu LA, Kottke TE, Brekke LN, Brekke MJ, Grill DE, Goraya TY, et al. Opportunities to prevent sudden out-of-hospital death due to coronary heart disease in a community. Resuscitation 2003;56: 55-58.[CrossRef][Web of Science][Medline]
6. Bunch TJ, White RD, Gersh BJ, Meverden RA, Hodge DO, Ballman KV, et al. Long-term outcomes of out-of-hospital cardiac arrest after successful early defibrillation. New Engl J Med 2003;348: 2626-2633.[Abstract/Free Full Text]
7. Albert CM, Mittleman MA, Chae CU, Lee I-M, Hennekens CH, Manson JE. Triggering of sudden death from cardiac causes by vigorous exertion. New Engl J Med 2000;343: 1355-1361.[Abstract/Free Full Text]
8. Bucher HC, Hengstler P, Schindler C, Meier G. N-3 polyunsaturated fatty acids in coronary heart disease: a meta-analysis of randomized controlled trials. Am J Med 2002;112: 298-304.[CrossRef][Web of Science][Medline]
9. Pitt B, Remme W, Zannad F, Neaton J, Martinez F, Roniker B, et al. Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study Investigators. Eplerenone, a selective aldosterone blocker, in patients with left ventricular dysfunction after myocardial infarction. New Engl J Med 2003;348: 1309-1321.[Abstract/Free Full Text]
10. Pitt B, Zannad F, Remme WJ, Cody R, Castaigne A, Perez A, et al. The effect of spironolactone on morbidity and mortality in patients with severe heart failure. Randomized Aldactone Evaluation Study Investigators. New Engl J Med 1999;341: 709-717.[Abstract/Free Full Text]
11. Rose G. Sick individuals and sick populations. Int J Epidemiol 1985;14: 32-38.[Abstract/Free Full Text]

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