Demographics Data was obtained from a 44 year follow up of the original Framingham Study and further 20 year surveillance of offspring. The data collected comprises of incidents of initial coronary events including recognised and clinically unrecognised MI, unstable angina, angina pectoris, and sudden and non-sudden coronary deaths. Key findings: The lifetime risk of developing CHD for persons aged 40 years is 32% for women and 49% for men. This risk drops for those aged 70 years where the lifetime risk is 24% for women and 35% for men. Age is a significant predictor of total coronary events, as incidences of events rises steeply with age, however men are more greatly affected than women. The sex ratio for incidents of coronary events narrows progressively with advancing age. Serious coronary events are relatively rare in premenopausal women. The incidence and severity in post menopausal women increases abruptly. 80% of incidences of angina in women is uncomplicated, while 66% of incidences of angina in men occur after a MI.
CHD Mortality In the United States adult population (over 35 years)
CHD is the leading cause of death and accounts for 1/3 of all deaths. Further, the overall death rate in the United States from cardiovascular disease is 220 per 100,000 which has declined compared to previous decades. The death rate is 3 times higher in men than women for those aged 25 to 34. For those aged 75 to 84, the death rathe is 1.6 times higher for men than women. While many incidence of myocardial infraction seem to occur without warning, there is evidence to suggest that there are silent CHD warning signs that are present and may have to predict further MI events. Patients who experience MI, have an ominous coronary risk assessment profile and are often presymptomatic. Exercise ECG and ambulatory ECG monitoring is effective in detecting compromised coronary circulation which is present in 2-4% of the general population. For asymptomatic men who with two or ore coronary risk factors such as smoking, obesity, family history, age over 45 years, diabetes, hypertension or hypercholesterolemia, the prevalence of silent ischemia may be as high as 10%. The prevalence of silent ischemia is even more common for patients with known coronary disease. In fact, the prevalence can range from 25 and 50% in patients with stable angina. Further, 70 to 80% of ischemia episodes are silent. Unrecognised MI: a Q wave MI, present on an ECG and in the absence of typical symptoms, is a good indication of silent myocardial ischaemia. Silent MI has a significant age dependency – between the ages of 40 and 60 in men and 35 and 70 in women, there is a steep increase in the incidences
Hypertension and diabetes mellitus. Hypertension: the severity of the hypertension can increase the incidence of both unrecognised and recognised infarctions. Undetected MIs are more common in hypertensives than normotensives. Diabetes Mellitus: risk factors of silent infarction that is only found in men. Women with diabetes were less likely to have unrecognised MIs, where as men with diabetes are twice as likely to have an unrecognised MI compared to those without diabetes.