1. Systolic hypertension is the number one correctable risk factor for CHD in the elderly.
a. Normal aging is associated with a 14% rise in systolic BP
b. More than 70% of 80 year olds will have systolic hypertension
c. Changes responsible for systolic hypertension include:
i. Increased collagen deposition in the aorta with decreased elastin fibers resulting in decreased compliance of the aorta
ii. Left ventricular contraction needs to be more forceful to overcome the increased afterload.
iii. With decreased compliance and increased left ventricular contractile force, the pressure pulse wave generated by the LV is larger.
iv. Diastolic Blood Pressure is not affected; therefore, the pulse pressure is increased in the elderly.
2. Left Ventricular Diastolic Dysfunction is found in more than 50% of those over the age of 70. It is the most common cause of heart failure in those over the age of 65.
a. Common causes include ischemia, LVH, and Asymmetric Septal Hypertrophy.
b. The increased LV contraction needed to overcome decreased aortic compliance results in LVH.
c. The time in systole is increased in the elderly due to increased afterload, resulting in a decreased time in diastole.
d. During diastole, there is a rapid filling phase early, followed by an atrial kick. The rapid filling phase does not occur in the elderly due to decreased compliance and "suction" of the left ventricle. The elderly patient is reliant on the atrial kick to fill the ventricle.
e. When there is an increase in the heart rate, there is decreased time for diastole, resulting in incomplete LV filling, increased Left atrial pressures, and increased pulmonary artery pressures.
f. Diagnosis of Diastolic Dysfunction is made by Echo Doppler. The "E" wave represents the rapid filling phase. THE "A" wave represents the atrial kick. With normal physiology the E/A ration should be > or = to 1. In diastolic dysfunction , that ratio is < one.
g. Management :
i. Treat Systolic Hypertension : in this clinical setting, B blocker, Ace inhibitor, and diuretics would all be appropriate choices
ii. Use negative ionotropes in attempts to increase relaxation and time in diastole.
iii. Digoxin would be contra-indicated
3. Hypercholesterolemia occurs as a result of increase in the LDL fraction with aging, especially in women. HDL really does not change with age.
a. The increase is thought to be due to decrease in the LDL receptors and therefore, decreased LDL catabolism.
b. Hyperlipidemia is a risk factor for CHD in the population over the age of 65, however, low HDL is the greatest risk factor in the elderly
c. The incidence of CHD increases linearly with age.
d. Treatment oactors include: smoking, menopause, carotid artery thickening, aortic sclerosis, homocyteinemia, and elevated inflammatory proteins, including CRP5. CAD in the elderly:
e. There is good data to support the treatment of hyperlipidemia in the elderly for secondary prevention.
f. There is no data on primary prevention in the elderly, but the recommendation is to treat the high-risk patient. Always recommend diet and exercise if appropriate.
4. Other risk Factors include: smoking, menopause, carotid artery thickening, aortic sclerosis, homocyteinemia, and elevated inflammatory proteins, including CRP
5. CAD in the elderly:
a. Only 50% of the elderly present with chest pain, and that is usually not typical
b. Anginal equivalents most commonly include dyspnea, even at rest, fatigue, nausea, anorexia, confusion. The 4 most important historical factors that relate to the likelihood of ischemia include:
i. Nature of angianl symptoms
ii. Prior history of CAD
iii. Age
iv. Number of risk factors
c. 20 to 40% of elderly have silent ischemia.
d. Diagnostic testing should be guided by you pre-test probability of the symptoms being unstable angina. If that pre-test probability is high, then one should go straight to cardiac catheterization. If one is uncertain, a stress echo or stress nuclear study would be appropriate.
i. Stress tests should not be done in patients with unstable angina or aortic stenosis.
ii. The catheterization should be done for treatment purposes, not for prognosis, as the degree of vascular disease in the elderly does not correlate with outcomes.
6. MI in the elderly
a. ER management
i. Monitor, O2, sl nitro, asa
ii. Hold nitro if BP is less than 90 or HR greater than 100
iii. Morphine for pain relief
iv. Fibrinolysis ( with-in 30 minutes) or PTCA with-in 90 minutes if ST elevation > 1mm or LBBB with positive enzymes
b. 1st 24 hours
i. Limit activity
ii. IV heparin or sc LMW
iii. ASA
iv. IV nitro for 24-48 hours
v. IV beta blockers if no contraindication
vi. Ace inhibitor
vii. HMGCoA reductase inhibitor
c. Revascularization in elderly falls way short of the indications ( odds ration of .44 that a patient over the age of 70 wii be revasularized.) The fact is, the elderly receive the most benefit.