Renovasc HTN Flashcards
What happens with 1K1C or bilateral renal artery stenosis?
- reduced renal perfusion –> ↑ RAS, ↑ renin, ↑ Ang II, ↑ aldosteron –> nml or ↓ ang II
- also, ↓ renal perfusion –> impaired Na+ and water excretion –> volume expansion –> ↑ arterial pressure; volume expansion can also inhibit RAS –> nml or ↓ ang II
- Effect of blockade of RAS: ↓ arterial pressure only after colume depretion; may ↓ GFR
- Diagnostic test: plasma rening activity nml or ↓; no lateralized featrues
What happens with unilateral renal artery stenosis (2K1C)?
- ↓ renal perfusion –> ↑ RAS, ↑ renin, ↑Ang II, ↑ aldosterone –> ang II-dependent HTN
- ↑ renal perfusion can lead to suppression of RAS or increased NA+ excretion (pressure natriuresis)
- Effect of blockade of RAS: ↓ arterial pressure, enhanced lateralization fo diagnostic tests, GFR in stenotic kidney may ↓
- Diagnostic test: plasma renin activity ↑; lateralization features (renal levels in renal vns, captopril-enhanced renography, etc.)
Lesions that can cause unilateral renal dz?
unilateral atherosclerotic renal a stenoisis, unilateral fibromuscular dysplasia, medial fibroplasia, perimedial fibroplasia, intimal fibroplasia, medial hyperplasia, renal a aneurysm, arterial embolus, AV fistula (congen/trauma), segmental arterial occlusion (post-trauma), extrinsic compression of renal a (pheochromocytoma), renal compression (met tumor)
Vasc lesions that can –> bilateral dz?
Stenosis to solitary functioning kidney, bilateral renal a stenosis, aortic coarctation, systemic vasculitis (ex Takayasu’s arteritis, polyarteritis), atheroembolic dz, vasc occlusion d/t endovascular aortic stent graft
What syndromes are assoc w/ renovascular HTN?
- Early or late onset HTN (<30 yrs, >50 yrs)
- Acceleration of treated essential HTN
- Deterioration of renal function in treated essential HTN
- ARF during trx of HTN
- Flash pulm edema**
- Progressive RF**
- Refractory CHF**
**appearance suggests bilateral renovasc HTN rather than primary HTN
Clinical features: Essential vs Renovascular HTN
- Renovascular HTN is more likely to… have a duration < 1 yr, age of onset >50 yrs, grade 3 or 4 fundi, abd bruit, BUN > 20, K+ < 3.4 mEq, urinary casts, and proteinuria
- Essential HTN is more likely to have a family Hx of HTN
Why do we no longer perform revascularization in pts with renovascular HTN?
Was performed for many years, and is now known that restoring vessel patency either w/ surgery or endovascular stenting fials to materially recover kidney function or add clinical benefit beyond that achievable with current medical therapy
Primary agents for oral anti-HTN drugs?
- Thiazides or thiazide-type diuretics: chlorthalidone preferred bc of prolonged t1/2 and ↓CVD; monitor hyponatremia and hypokalemia, uric acid and Ca levels; use caution in pts w/ hx of gout
- ACEI: not in combo with ARBs or direct renin inhibitor; ↑ risk for hyperkalemia, esp in CKD, risk for ARF in pts with servere bilat renal a stenosis; dont use in pt w/ ACEI angioedema; no preggers
- ARBs: no combo with ACEI or direct renin inhibitors; ↑ risk hyperkalemia in CKD, risk of ARF w/ severe bilat renal a stenosis; Don’t use if hx of angioedema with ARBs; no preggos
- CCB - dihydros: avoid in pts with HFrEF; amlodipine or felodipine may be used; assoc w/ dose-related pedal edema, F>M
- CCBs - non-dihydros: avoid routing BBs bc of ↑ risk bradycardia and heart block; drug interaxns with diltiazem and verapamil (CYP3A4)
Oral anti-HTN drugs - Second Agents?
- Loop diuretics: preferred in pts w/ symptomatic HF and over thiazides in pts w/ mod-severe CKD
- K+ sparing: monotherapy agents and minimally effective anti-htn agents; combo therapy with K+ spareing w/ thiazide can be considered in pts w/ hypokalemia; avoid in pts w/ significant CKD
- Aldosterone antagonists: preffered in primary aldosteronism and resistant HTN; spironolactone is assoc with greater risk of gynecomastia and impotence vs eplerenone; common add-on in resistant HTN; avoid use w/ K+ supps, K+ sparing diuretics, or significant renal dysfunction; eplerenone often requires 2x daily dosing for ↓ BP
- Beta-blockers (cardioselective): no recommended as first line unless pt has ischmeic heart dz or HF; preferred in pts w/ bronchospastic airway dz; bisoprolol and metoprolol succinate are preffered in HFrEF pts; avoid abrupt stop
- BBs (cardioselective & vasodilatory): nebivolol induces NO-induced vasodilation; avoid abrupt stop
- BBs (noncardioselective): avoif in pts w/ reactive airway dz; avoid abrupt stop
- BB (intrinsic sympathomimetics): avoid, esp in ischemic heart dz or HF; avoid abrupt stop
- BBs- combined alpha & beta Rs: carvedilol preferred in HFrEF; avoid abrupt stop
- Direct renin inhibitor: no in combo with ACEI or ARB; alsikiren is long acting; ↑ risk for hyperkalemia in CKD; can cause ARF in pts w/ severe bilat renal a stenosis; avoid in preggos
- Alpha1 blockers: assoc with orthstat hypoTN; considered second-line agent in pts w/ BPH
- Central alpha2 agonists: last-line bc of CNS adverse effx; avoid abrupt stop to clonidine –> hypertensive crisis, must be tapered
- Direct vasodilators: assoc with Na+ and water retention and reflex tachy; use with diuretic and BB; hydralazine assoc w/ drug-induced lupus-like syndrome at higher doses; minoxidil is assoc w/ hirsutism and requires loop diuretic, and can induce pericardial effusion
Trx of HTN w/ stbale ischemic heart dz?
- Reduce BP to <130/80 w/ GDMT BBs, ACEI, or ARBs (class I) –> BP goal not met –> angina pectoris –> Yes –> add dihydro CCBs if needed (class I); if no angina –> add dihydro CCBS, thiazide-type diuretics, and/or MRAs as needed (class I)
Trx of HTN in pts w/ CKD?
- BP goal <130/80 –> albuminuria (>300 mg/dL or > 300 mg/g creatinine) –> no –> use first-line choice
- if yes –> ACEI (class IIa) –> ACEI intolerant –> ARB (class IIb)
What is the recommendation for prevention of HF in adults w/ HTN?
Optimal BP should be less than 130/80
What is the recommendation for trx of HTN in pts w/ HFrEF?
- Should be prescribed GCMT titrated to attain bP less than 130/80
- Non-DHP CCBs not recommended in trx
What is the recommendation of treatment of HTN in pts with HFpEF?
- If presenting with sx of volume overload, diuretics should be prescribed
- If have persistent HTN after diuretic added, should be prescribed ACEI or ARBs and BBs titrated to attain SBP < 130
What is the recommendation for trx of HTN after renal transplant?
- BP goal < 130/80
- Calcium antagonist on the basis of improved GFR in kidney survival
