Ineffective Secondary Prevention in Survivors of Cardiovascular Events in the US Population

Abstract

CARDIOVASCULAR diseases (CVDs), including myocardial infarction (MI) and stroke, are a major cause of death and disability in the United States.¹ A history of CVD increases the relative risk of subsequent premature cardiovascular morbidity and mortality by 5 to 7 times.^2,3 The survival rate among more than 1 million cases of MI that occur annually is approximately 70% to 80%.^4,5 Among survivors of a first MI, the rate of subsequent MI is increased 3 to 6 times, and the risk of any CVD event may be as high as 80%.⁶ Of approximately 500 000 new and recurrent strokes that occur each year in the United States, 80% of the patients survive the event.⁷ The risk of subsequent ischemic stroke is as high as 30%, with a 2-fold increase in subsequent cardiovascular events.^8-10 Because persons with a previous history of cardiovascular events are at high risk for future MI and stroke, aggressive intervention that includes risk factor modification is warranted in this population. Despite advances in medical and surgical management of CVD, long-term survival depends on modification of underlying disease processes. Considerable evidence exists that a secondary prevention program to reduce CVD risk factors can favorably impact CVD morbidity and mortality.⁴ Survivors of these events are ideal candidates for secondary prevention efforts because even modest treatment effects could benefit this large at-risk population. Most survivors receive medical evaluation regularly, and risk factor modification can be undertaken in a cost-effective manner. To our knowledge, limited information exists regarding formal assessment of the magnitude of risk factor modification with current secondary preventive strategies outside clinical trials. The present study was undertaken to determine the effectiveness of secondary preventive measures in survivors of MI and stroke using data from the Third National Health and Nutrition Examination Survey (NHANES III), a nationally representative sample of US adults, and to identify factors related to inadequate control of risk factors.