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Reviewing a case of stage II hypertension in a 50-year-old man and discussing evaluation, diagnosis, risk factors, treatment options, and lifestyle modifications to prevent cardiovascular events.
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Hypertension Review Cases By Mayssa Ibrahim Aly Professor of Internal Medicine-Cairo University 2009
A 50-year-old black man • has a blood pressure of 160/110 mm Hg on repeated measurements. • He is 9 kg overweight, • has a family history of hypertension, and smokes one pack of cigarettes daily.
How should this patient be evaluated?
Classification according to BP level • Normal <120/80 • Pre-hypertension 129/80—139/89 • Hypertension >140/90
Hypertension • Stage I 140-159/90-99 • Stage 2 >160/100
The five-year risk of a major cardiovascular event in a 50-year-old man with a blood pressure of 160/110 mm Hg is 2.5 to 5.0 percent; • The risk doublesif the man has a high cholesterol level and triples if he is also a smoker
The primary goal of the treatment of hypertension is to prevent cardiovascular disease and death
In stage 1 or 2 hypertension lowering systolic pressure by 10 to 12 mm Hg and diastolic pressure by 5 to 6 mm Hg reduces the risk of • stroke by 40 %, • coronary disease by 16 %, and • death from any cardiovascular cause by20 %.
What are the major Risk Factors?
Risk Factors • 1. Smoking • 2. Dyslipidemia • 3. DM • 4.>60ys • 5. Men& postmenopausal women • 6. Obesity • 7. FH of CVD: • Men<55ys or Women<65ys
Patients with stage 1 HTN can be treated with lifestyle modifications alone for up to one year, if they have no other risk factors, or • for up to six months, if they have other risk factors.
Lifestyle modifications and antihypertensive therapy are indicated for: • patients with cardiovascular or other target-organ disease (renal, cardiac, cerebrovascular, or retinal disease) and • those with stage 2
Patients with diabetes are at high risk, and drug therapy is indicated in such patients even if BP is at the high end of the normal range
Restriction of sodium intake to 2 g/dlowers systolic pressure, on average, by 3.7 to 4.8 mm Hg and lowers diastolic pressure, on average, by 0.9 to 2.5 mm Hg. • Salt sensitivity is common in elderly patients with hypertension
Which one? Which anti-hypertensive drug will you choose ?
Rules • Most antihypertensive drugs reduce blood pressure by 10 to 15 percent. • Monotherapy is effective in about 50 percent of unselected patients
Those with stage 2 HTN often need more than one drug. • Evaluation for 2ry HTN should be considered when three or more antihypertensive drugs of different classes do not control blood pressure
Step1 Step2 Algorithm for Manag. of HTN Step3 Step4
Diuretics are appropriate as first-line therapy for patients without coexisting conditions • ACE inhibitors or angiotensin-receptor antagonists are recommended for patients with type 2 diabetes, kidney disease, or both and are also useful in patients with heart failure.
Beta-blockers and ACE inhibitors are recommended in patients with prior myocardial infarction, and • Calcium-channel antagonists benefit elderly patients at risk for stroke
What's about our patient?
Which Stage of HTN? What are the risk factors for HTN ?
The patient should be advised to: • A) lose weight, • B) stop smoking, • C) engage in regular exercise, and • D) modify his diet and • He should be screened for vascular disease and other cardiovascular risk factors.
The increase in dietary salt may also have contributed to the growing obesity problem by causing increased intake of fluids, particularly of high-calorie soft drinks
If No coexisting disease was detected • Hydrochlorothiazide at a dose of12.5mg daily. • If this dose did not control his blood pressure increase it or add a second drug • for example, an ACE inhibitor to prevent the adverse metabolic effects of higher doses of diuretics
The upstream portion of the distal convoluted tubule is the major site of action of the thiazides, where they interfere with sodium re-absorption. • Sodium is reabsorbed in the distal tubule and collecting ducts through an aldosterone-sensitive sodium channel and by activation of an ATP-dependent sodium–potassium pump.
Through both mechanisms, potassium is secreted into the lumen. • "K+-sparing agents" collectively refers to the epithelial sodium-channel inhibitors (e.g., amiloride and triamterene) and mineralocorticoid-receptor antagonists (e.g., spironolactone and eplerenone).
The onset of action occurs after approximately 2 to 3 hours for most thiazides, with little natriuretic effect beyond 6 hours. • Most thiazides have a half-life of approximately 8 to 12 hours, just permitting effective once-daily dosing
Initial decreases in blood pressure are attributed to the reductions in extra-cellular fluid and plasma volumes, leading to depressed cardiac preload and output. • Activation of the sympathetic NS and the renin–angiotensin–aldosterone system induces a transient rise in peripheral vascular resistancebutnotsufficient to negate the blood-pressure reduction
Combining a Thiazide with (ACE) inhibitor or an angiotensin II–receptor blocker (ARB) can oppose this transient rise in resistance and increase the antihypertensive response.
Thiazides induce a reduction in the systolic and diastolic blood pressures of 10 to 15 mm Hg and 5 to 10 mm Hg, respectively
Who will respond to Thiazides?
Hypertension responding preferentially to thiazides is considered to be low-renin or salt-sensitive hypertension. • The elderly, blacks, and patients with characteristics associated with high cardiac output (e.g., obesity) tend to have this type of HTN.
What's about the dose used?
Hydrochlorothiazide at a dose of 12.5 to 25 mg/d. • Approximately 50% of patients will respond initially to these low doses.
Increasing the dose of hydrochlorothiazide from 12.5 to 25 mg/d may result in a response in an additional 20% (approximately) of patients. • At 50 mg /d, 80 to 90% of patients should have measurable decreases in blood pressure. • Increased electrolyte losses at the higher doses of diuretics may preclude their routine use
