BASED on American Heart Association data published in the Circulation journal in 2002, studies from autopsies indicate that in those aged 70 years or more, blockage of heart arteries was present in about 50 per cent of women and 80 per cent of men. This elderly group accounts for up to 40 per cent of all heart attacks and 60 per cent of all deaths related to heart attack. Hence, heart disease will afflict a large majority of people as they grow older and its impact is larger in the older group. Understanding heart disease will help us to keep our heart "strong" as we grow older.
Recognising symptoms of heart disease
While most people dread the diagnosis of cancer more than the diagnosis of heart disease, it may be sobering to know that following the first heart attack, those in their middle age are likely to have a median survival of about 17 years in men and 13.3 years in women and this decreases significantly to 3.2 years in both sexes in those 75 years and above.
The presence of chest tightness or pain on exertion is typical of the presence of significant blockage of the heart arteries. However, even in those below the age of 65 who present to a hospital with a heart attack, only about three quarters have chest pain and this decreases to 40 per cent in those 85 years and above. Less recognised heart attack symptoms, which include shortness of breath, sweating, nausea and fainting, often result in heart attacks being unrecognised. Heart attacks can also be silent without any symptoms, the incidence increasing from one quarter in the young to two thirds in the elderly.
Over a five-year period, up to 10 per cent of these heart attack patients will develop a stroke, mostly due to blockage of the brain arteries. Blockage of the arteries in the legs is also correlated with the presence of heart disease. Up to 50 per cent of these patients have no symptoms and about one-fifth may have pain in the calves on walking. In a study published by Ness in the Journal of the American Geriatric Society in 1999, close to 80 per cent with narrowing of the leg arteries had heart disease and previous stroke. Hence, pain in the calves while walking should alert one to look for presence of heart disease and stroke risk.
Managing risk factors
High blood pressure, high cholesterol levels, diabetes mellitus and smoking are known risk factors for heart artery disease. Managing these risk factors are important for the prevention of adverse outcomes in those with heart disease. Most studies which demonstrate the benefits of treatment of heart disease,whether it be medication or invasive procedures, are in relatively younger patients and the data may not necessarily be extrapolated to the very elderly patients.
Age-related changes resulting in stiffer arteries, less elastic heart muscles, gradual reduction in kidney function, muscle mass reduction and changes in brain function present challenges in the management of heart disease in the elderly. Age related bodily changes have implications for treatment. First, in the elderly, more than 90 per cent of those with high blood pressure have elevated systolic blood pressure (SBP or upper value of blood pressure reading) with no elevation of the diastolic blood pressure (DBP or lower blood pressure value). Contrary to popular belief that the increase in SBP in the elderly is a normal part of ageing, the HYVET study published in 2008 in the New England Journal of Medicine showed that treatment of isolated SBP elevation was associated with reduction in stroke, heart failure and death.
Stress reduction, weight reduction, salt restriction, alcohol reduction, smoking cessation, increased exercise and low fat diet may help to decrease the blood pressure. In the elderly, blood pressure medication which can cause a sudden drop in pressure from changing from a lying to a standing position (postural hypotension) may increase the risks of falls. Let your doctor know if you feel dizzy on standing up as you may have postural hypotension or there may be excessive lowering of blood pressure.
Beta blockers and certain calcium channel blockers (verapamil and diltiazem), which are drugs that lower the blood pressure and can slow the heart rate, are routinely given to heart patients but they can also aggravate age-related abnormalities in the heart electrical conduction system causing dangerously low heart rates and a drop in blood pressure.
Second, while cholesterol reduction using cholesterol lowering drugs, called statins, have demonstrated significant reduction in heart attack, strokes and deaths, these potential benefits must be balanced against the risk of statin-induced muscle aches and potential memory impairment which can have a significant impact on the mobility and quality of life in the elderly. Careful attention must be paid to those who complain of deteriorating memory after commencement of statins.
Third, although strict diabetic control is the norm for younger patients, for the elderly patients, a higher blood sugar target is acceptable as they are at much higher risk of drug-induced low blood sugar and the resultant coma may bring about permanent brain damage.
Fourth, blood-thinning agents such as aspirin or clopidogrel are commonly given to reduce the risk of heart attack and stroke but this must be balanced against the increased risk of bleeding from the stomach, intestine and brain. Hence, where possible, only one blood-thinning agent should be given and this should be taken together with medication that reduces stomach acidity.
Fifth, vitamin deficiencies are common among the elderly as a result of decreased dietary consumption and decreased ability of the intestines to absorb such vitamins and minerals. Among the vitamins, vitamin D deficiency has been identified as a risk factor for death from heart disease in the elderly. Vitamin D deficiency is common in the elderly because of reduced sun exposure, decreased production in the skin and inadequate intake of the vitamin in foods. While taking Vitamin D appears to be beneficial, recent trials on omega 3 fatty acids and vitamin B intake have shown no significant benefits in preventing heart disease.
Six, personality and psychological factors are also important in the management of heart disease in the older patients. Those with a hostile character, have depression and have high stress are more likely to have adverse outcomes such as precipitating a heart attack or increased risk of death. Treating depression can be beneficial.
To treat or not to treat
Finally, we often hear the familiar refrain that "he is too old to be treated" for those elderly patients with chest pain refractory to medication. For elderly patients with known heart disease, there will always be an option between medication versus invasive procedures such as stenting or open heart bypass surgery.
The TIME (Trial of Invasive versus Medical therapy in Elderly patients) study published in the Circulation journal in 2004 looked at elderly patients with a mean age of 80 years who had chest pain, and found that those who underwent treatment with stenting or bypass surgery had less adverse outcomes than those who were just on medication alone. Hence, in making a decision, the biological age rather than the physical age of the patient should be the main deciding factor. Even for those in their 80s, it is never too late to treat their heart disease.
- Dr Lim is medical director at the Singapore Heart, Stroke & Cancer Centre. He is also editor-in-chief, Heart Asia (a journal of the British Medical Journal Publishing Group); chairman, scientific advisory board, Asia Pacific Heart Association; and honorary professor and senior medical adviser, Peking University Heart Centre
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