It is in this regard that research has been able to detect “hypertension” as a primary risk factor for heart disease. And it preceded three-quarters of heart failure cases compared to coronary artery disease, which led to most heart failures in less than 40% of cases. Furthermore, an increase in left ventricular end-diastolic diameter became a mirror of the Framingham study as incident heart disease in individuals free of myocardial infarction. Although studies have shown that the manifestation of heart failure can be present without left ventricular systolic dysfunction, other risk factors could lead to it. In addition, they (Framingham study) were able to detect “excess cholesterol” as a link to cardiovascular disease. In addition, research has shown that increases in certain heart diseases, such as coronary heart disease, often lead to strokes and high blood pressure in many patients. That said, research has found "obesity" also co-occurring with lipid-elevating hypertension and diabetes in relation to questions about smoking behavior. That said, these risk factors are believed to be attributed to heart disease. It therefore became a national concern for the American population in general and that of the fourth director of the Framingham Heart Study, William Castelli.