Hypertension Flashcards
Pre-Hypertension
Classification and management
- systolic bp 120-139 mm Hg
- diastolic bp 80-89 mm Hg
- without compelling indication - no drug therapy indicated
- with compelling indication - drugs for compelling indication
Stage 1 HTN
Classification and management
- SBP - 140 - 159 mm Hg
- DBP - 90 - 99 mm Hg
- without compelling indication - thiazide-type diuretic, ACEI, ARB, DHP-CCB
- with compelling indication - drugs for compelling indications. other antihypertensives as needed
Stage 2 HTN
Classification and management
- SBP of 160 mm Hg or greater
- DBP of 100 mm HG or greater
- Without compelling indication: two drug combination for most (usually thiazide-like diuretic and ACEI, ARB or DHP-CCB)
- with compelling indication - drugs for compelling indications. Other antihypertensives as needed
Identifiable causes of HTN
- sleep apnea
- drug induced or related causes
- CKD
- primary aldosteronism
- renovascular disease
- chronic steroid therapy or Cushings syndrome
- pheochromocytoma
- coarctation of the aorta
- thyroid or parathyroid disease
Risks of HTN
- pts 40 -70 years each increment of 20mmHg SBP or 10mmHg DBP doubles the risk of CVD across the range of 115/75 - 185/115 mmHg
- Target organ damage:
- heart
- left ventricular hypertophy
- angina or MI
- coronary revascularization
- heart failure (HF)
- reduced left ventricular ejection fraction
- preserved left ventricular EF
- brain - stroke or TIA
- CKD
- PAD
- Retinopathy
- heart
Benefits of Lowering BP
- Associated with the relative risk reduction in the incidence of:
- Stroke - 35-40%
- MI - 20-25%
- HF - greater than 50%
- in patients with stage 1 HTN and additional cardiac risk factors, achieving a sustained 12mm Hg over 10 years will prevent one death for ever 11 patients treated
- In the presence of CVD or other target organ damage, only nine patients would require such a BP reduction to prevent a death.
Accurate BP measurement
- seated quietly for 5 minutes with feet on floor, back supported, and arm supported at heart level
- appropriate sized cuff
- at least two measurements should be made
- clinicians should provide to patients, both verbally and in writing, their specific BP readings and goals
Self-Measurement of BP
- helpful in evaluating white-coat HTN and long-term BP monitoring
- home measurement devices should be checked regularly for accuracy
- Automatically inflating arm devices are preferred over wrist monitors or manual inflation devices for accuracy
Lifestyle modification and HTN
1) weight reduction
- can reduce SBP by 5-20 mm HG for every 10kg
2) diet
- DASH diet can reduce SBP by 8-14 mm Hg
- Na restriction can reduce SBP by 2-8 mm Hg
3) exercise
- 30 minutes of aerobic activity on most days of the week can reduce SBP by 4-9 mm HG
4) moderation of alcohol consumption
- limiting to no more than two drinks a day for men or one drink a day for women can reduce SBP by 2-4 mm Hg
ACEIs
Mechanism of action
- prevents conversion of angiotensin I to angiotensin II (potent vasoconstrictor) by competitive inhibition of ACE
- results in lower BP secondary to lower levels of angiotensin II, increased levels of plasma renin activity, and a reduction in aldosterone secretion
ACEIs
Evidence
- HOPE (Heart Outcomes Prevention Evaluation Study)
- effects of ramipril on CV events in high risk patients - EUROPA
- efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease - PEACE
- ACEI in stable coronary artery disease - PROGRESS
- randomized trial of a perindopril-based BP lowering regimen among 6,105 patients with previous stroke or TIA - SAVE (Survival and Ventricular Enlargement trial)
- effect of captopril on maortality and morbidity in patients with left ventricular dysfunction after MI
ACEIs
Clinical use
- Compelling indications to use ACEIs 1st line
- DM - reduces the progression of nephropathy and alunminuria
- CKD - reduces the progression of diabetic and non diabetic renal disease
- HF or left ventricular dysfunction with LVEF <40%
- Post MI
- High CAD risk
- recurrent stoke prevention - reduces recurrence when used in combination with thiazide diuretic
- Recommended add-on therapy to thiazide diuretic
ACEIs
contraindications
- bilateral renal artery stenosis
- pregnancy
- angioedema
ACEIs
Important adverse drug reactions
- increasing Cr - limited rise as much as 30% above baseline is acceptable. This becomes the patients new baseline
- hyperkalemia
- angioedema - occurs two to four times more frequently in African Americans
- cough (dry)
ACEIs
Dosing and monitoring
- consider avoiding in women during childbearing years
- consider starting at lower-than-average dose if patient id elderly, in on concommitant diuretic therapy or has renal impairment
- Monitor Cr and K 7-10days after initiation or titration
ARBs
Mechanism of action
- selective, competitive antiotensin II receptor type 1 receptor antagonist, reducing end-organ response to angiotensin II
- results in decreased total peripheral resistance (afterload) and cardiac venous return (preload)
- reduction in BP occurs independently of the status of the renin-antiotensin system
ARBs
Evidence
- LIFE - Losartan Intervention for Endpoint reduction in hypertension study
- randomized trial against atenolol
- VALIANT
- valsartan, captopril, or both in MI complicated by HF, left ventricular dysfunction, or both
ARBs
Clinical use
- recommended as first line, but generally reserved for patients who have ACEI intolerance
- Compelling indications (typically after ACEI fail)
- HF or left ventricular systolic dysfunction with LVEF of 40% or less
- DM - reduces the progression of nephropathy and albuminuria
- CKD - reduces the progression of diabetic and non diabetic renal disease
ARBs
Contraindications
- bilateral renal artery stenosis
- pregnancy
- angioedema (ARB-induced or idiopathic)
- although ARBs may be considered alternative therapy for patients who have developed angioedema while taking an ACEI, patients have also developed angioedema with ARBs.
- extreme caution is advised when substituting an ARB in a patient who has had angioedema associated with ACEI use
- although ARBs may be considered alternative therapy for patients who have developed angioedema while taking an ACEI, patients have also developed angioedema with ARBs.
ARBs
Important adverse drug reactions
- Increasing SCr - limited rise of as much as 30% above baseline is acceptable. This becomes the patients new baseline
- hyperkalemia
- angioedema - less than with ACEIs
ARBs
Dosing and monitoring
- consider avoiding in women during childbearing years
- monitor Scr and K 7-10 days after initiation and titration
Renin inhibitor (aliskiren) Mechanism of action
- direct renin inhibition
- decreasing plasma renin activity and inhibiting the conversion of angiotensinogen to angiotensin I
Renin inhibitor (aliskiren) Evidence
- no outcomes data available for aliskiren mono therapy
- ALTITUDE - Aliskiren Trial in Type 2 Diabete Using Cardiovascular and Renal Disease Endpoints
- trial terminated early
- aliskiren added to ACEI or ARB therapy in patients with type 2 DM and renal impairment compared with placebo
- an increase in adverse events (nonfatal stroke, renal complications, hyperkalemia and hypotension)
- no apparent benefit to patients randomized to aliskiren
Renin inhibitor (aliskiren) Contraindicaitons
- pregnancy
- do not use with ARBs or ACEIs in patients with diabetes
Renin inhibitor (aliskiren) Important adverse drug reaction
- angioedema
- hyperkalemia if used concomitantly with ACEI
Renin inhibitor (aliskiren) Dosing and monitoring
- consider avoiding in women during childbearing years
- high-fat meals decrease absorption substantially
- patients with renal insufficiency were excluded from trials
Beta blockers
Mechanism of action
- selective (beta-1) or nonselective (beta1 and 2) receptor blocker results in negative inotropic and chronotropic actions
- some (pindolol and acebutolol) exhibit intrinsic sympathomimetic activity meaning they are cpable of exerting low-level agonist activity at the beta receptor while simultaneously acting as an antagonist
- cardioselective agents without intrinisic sympathomimetic activity are usually used for HTN
- Carvedilol and labetalol also have alpha1 blocking activity
Beta blockers
Evidence
ACCF/AHA guidelines since the 1980s
Beta blockers
clinical use
1) Compelling indications
- HF or left ventricular systolic dysfunction wiht LVEF <40% or less - 1st line with ACEI
- Post-MI (within first 3 yearr) = First line
- High CAD risk
- DM
2) Controversy regarding the appropriateness of using as first line agent in patients without a compelling indication.
Beta-blockers with alpha1-blocking activity are likely more effective antihypertensive agents than beta-blockers without this mechanism
Beta-blockers
Contraindications
- SA or AV node dysfunction
- decompensated HF
- severe bronchospastic disease
Beta-blockers
Important adverse drug reactions
- bradycardia
- heart block
- bronchospastic disease
- exercise intolerance, sexual dysfunction, fatique
Beta-blockers
Dosing and monitoring
- relative contraindications include significant sinus or AV note dysfunction, hypotension, decompensated HF, and severe bronchospastic lunch disease
- Monitor HR regularily
Thiazides
- hydrochlorothiazide
- chlorthalidone
- metolazone
- indapamide
Thiazides
Mechanism of action
- Acts on kidneys to reduce Na reabsorption in the distal convoluted tubule.
- by impairing Na transport in the distal convoluted tubule, natriauresis and concomitant water loss in induced
Thiazides
Evidence
- ALLJAT
- Preventnion of stroke by antihypertensive drug treatment in older people with isolated systolic HTN: Final results of the Systolic Hypertension in the Elderly Program (SHEP)
- Medical Research Council (MRC) trial of treatment of mild hypertension: Principal results