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Epidemiology and risk profile of cardiac failure
1Section of Preventive Medicine and Epidemiology, Boston University School of Medicine, MA 02118.
Insights
Heart failure (HF) incidence rises with age, with hypertension and coronary heart disease (CHD) as primary causes. Identifying key risk factors like elevated blood pressure and ECG-LVH can predict HF events.
Area of Science:
- Cardiology
- Epidemiology
- Public Health
Background:
- Cardiac failure, or heart failure (HF), is a growing public health concern.
- Understanding its epidemiology, including prevalence, incidence, and trends, is crucial for effective prevention and management.
- The Framingham Heart Study offers a unique, long-term dataset for examining HF in a large population.
Purpose of the Study:
- To analyze the epidemiology of heart failure over three decades using Framingham Heart Study data.
- To identify key risk factors and prognostic indicators for cardiac failure.
- To assess the predictive power of various clinical and electrocardiographic findings for HF development.
Main Methods:
- Longitudinal cohort study analysis of Framingham Heart Study participants over 30 years.
- Examination of prevalence, incidence rates, and secular trends of heart failure.
- Statistical analysis of risk factors including hypertension, coronary heart disease (CHD), myocardial infarction (MI), and electrocardiographic (ECG) abnormalities.
Main Results:
- Annual incidence of HF increases significantly with age, from 3/1000 (ages 35-64) to 10/1000 (ages 65-94).
- Hypertension and CHD are the leading causes of HF; hypertension triples HF risk, with systolic BP being more predictive.
- Silent MIs and ECG-LVH (left ventricular hypertrophy) are significant predictors of HF, with ECG-LVH posing a higher risk than radiographic enlargement.
- A combination of standard risk factors (age, systolic BP, cholesterol, glucose, smoking, ECG-LVH) can identify a high-risk group for HF events.
Conclusions:
- Heart failure incidence escalates with age, primarily driven by hypertension and CHD.
- Modifiable risk factors such as elevated blood pressure, cholesterol, obesity, and glucose intolerance significantly increase HF risk.
- ECG abnormalities, particularly ECG-LVH, are strong indicators of HF risk and prognosis.
- A predictive model using common cardiovascular risk factors can identify individuals at substantial risk for developing heart failure.
Abstract:
A three-decade examination of the prevalence, incidence, secular trends, and prognosis of cardiac failure in the Framingham Study provides insights into its epidemiology. Annual incidence of CHF is observed to increase from 3 to 1000 at ages 35-64, to 10 per 1000 at ages 65-94. There is a slight male predominance, owing to a higher rate of coronary disease, which conferred a fourfold risk of cardiac failure. Most cardiac failure is on the basis of long-standing hypertension or CHD. Silent infarctions were as predisposing for CHF as symptomatic MIs surviving 1 year. Hypertension is a major predisposing factor that at least triples the CHF risk, the systolic component being more predictive than the diastolic component. Correctable predisposing risk factors for CHF include: elevated blood pressure, impaired glucose tolerance, elevated cholesterol, low HDL-cholesterol, obesity, and a high hematocrit. Risk factors reflecting deteriorating cardiac function also were highly predictive, including: an enlarged heart, poor vital capacity, sinus tachycardia, and ECG-LVH. Commonly encountered ECG abnormalities such as intraventricular block, nonspecific repolarization abnormality, and ECG-LVH are all associated with a substantial risk of CHF. ECG-LVH carries a higher risk than x-ray enlargement. Sudden death was a common feature with CHF, occurring at 5 times the general population rate, even excluding those with overt CHD. Using the standard cardiovascular risk factors (age, systolic blood pressure, cholesterol, glucose, cigarettes, and ECG-LVH) jointly, it is possible to identify one tenth of the population from which 40% of CHF events evolve, in the absence of interim CHD or RHD.