Pocket Medicine

CARDIOLOGY

HYPERTENSION

BP should be determined by making ≥2 measurements separated by >2 min. Confirm stage 1 w/in 2 mo; can Rx stage 2 immediately.

Epidemiology ( JAMA 2003;290:199 & 2010;303:2043)

•  Prevalence 30% in U.S. adults; >68 million affected (29% in whites, 33.5% in blacks)

•  Only 50% of patients with dx of HTN have adequate BP control

Etiologies

•  Essential (95%): onset 25–55 y;  FHx. Unclear mechanism but ? additive microvasc

renal injury over time w/ contribution of hyperactive sympathetics (NEJM 2002;346:913).

↑ Age → ↓ arterial compliance → syst HTN. Genetics also involved (Nature 2011;478:103).

•  Secondary: Consider if Pt <20 or >50 y or if sudden onset, severe, refractory HTN

Standard workup

•  Goals: (1) identify CV risk factors or other diseases that would modify prognosis or Rx;

(2) reveal 2° causes of hypertension; (3) assess for target-organ damage

•  History: CAD, HF, TIA/CVA, PAD, DM, renal insufficiency, sleep apnea, preeclampsia;  FHx for HTN; diet, Na intake, smoking, alcohol, prescription and OTC meds, OCP

•  Physical exam: ✓ BP in both arms; funduscopic exam, cardiac (LVH, murmurs), vascular (bruits, radial-femoral delay), abdominal (masses or bruits), neuro exam

•  Testing: K, BUN, Cr, Ca, glc, Hct, U/A, lipids, TSH, urinary albumin:creatinine (if ↑ Cr, DM, peripheral edema), ? renin, ECG (for LVH), CXR, TTE (eval for valve abnl, LVH)

Complications of HTN

•  Each ↑ 20 mmHg SBP or 10 mmHg DBP → 2× ↑ CV complications (Lancet 2002;360:1903)

•  Neurologic: TIA/CVA, ruptured aneurysms, vascular dementia

•  Retinopathy: stage I = arteriolar narrowing; II = copper-wiring, AV nicking; III = hemorrhages and exudates; IV = papilledema

•  Cardiac: CADLVHHF, AF

•  Vascular: aortic dissection, aortic aneurysm (HTN = key risk factor for aneurysms)

•  Renal: proteinuria, renal failure

Treatment (Lancet 2012;380:591)

•  Goal: <140/90 mmHg; if DM or CKD goal is <130/80 mmHg (nb, in DM, target of <120 does not ↓ CV risk & ↑ adverse events; NEJM 2010;362:1575)

•  Treatment results in 50% ↓ HF, 40% ↓ stroke, 20–25% ↓ MI (Lancet 2000;356:1955); benefits of Rx’ing stage II HTN extend to Pts >80 y, goal BP <150/80 (NEJM 2008;358:1887)

•  Lifestyle modifications (each ↓ SBP ~5 mmHg)

weight loss: goal BMI 18.5–24.9; aerobic exercise: ≥30 min exercise/d, ≥5 d/wk

diet: rich in fruits & vegetables, low in saturated & total fat (DASH, NEJM 2001;344:3)

sodium restriction: ≤2.4 g/d and ideally ≤1.5 g/d (NEJM 2010;362:2102)

limit alcohol consumption: ≤2 drinks/d in men; ≤1 drink/d in women & lighter-wt Pts

•  Pharmacologic options (if HTN or pre-HTN + diabetes or renal disease)

Pre-HTN: ARB prevents onset of HTN, no ↓ in clinical events (NEJM 2006;354:1685)

HTNchoice of therapy controversial, concomitant disease and stage may help guide Rx

uncomplicated: thiazide if likely salt sensitive (eg, elderly, black, obese), o/w start w/ ACEI or CCB (NEJM 2009;361:2153). bB not first line (Lancet 2005;366:1545).

+high-risk CAD: ACEI or ARB (NEJM 2008;358:1547); ACEI + CCB superior to ACEI + thiazide (NEJM 2008;359:2417) or bB + diuretic (Lancet 2005;366:895)

+angina: bB, CCB, nitrates

+post-MI: ACEI, bB ± aldosterone antagonist (see “ACS”)

+HF: ACEI/ARB, bB, diuretics, aldosterone antagonist (see “Heart Failure”)

+2° stroke prevention: ACEI (Lancet 2001;358:1033); ? ARB (NEJM 2008;359:1225) +diabetes mellitus: ACEI or ARB; can also consider diuretic, bB or CCB

+chronic kidney disease: ACEI/ARB (NEJM 1993;329:1456 & 2001;345:851 & 861)

•  Tailoring therapy

if stage 1, start w/ monoRx; if not at goal, Δ to different class rather than adding 2nd agent

if stage 2, consider starting w/ combo (eg, ACEI + CCB; NEJM 2008;359:2417) as most will require ≥2 drugs; low–mod doses of 2 drugs generally preferred over max dose of 1 drug (b/c of dose-related AEs)

if resistant [= HTN despite ≥3 drugs (incl diuretic) at opt doses], consider noncompliance, volume overload, secondary causes; ? renal artery denervation (Lancet 2010;376:1903)

•  Secondary causes

Renovascular: control BP w/ diuretic + ACEI/ARB (watch for ↑ Cr w/ bilat. RAS) or CCB Atherosclerosis risk-factor modification: quit smoking, ↓ chol. If refractory HTN, recurrent flash pulm edema, worse CKD, consider revasc

For atherosclerosis: stenting ↓ restenosis vs. PTA alone, but no clear improvement in BP or renal function vs. med Rx (NEJM 2009;361:1953; Annals 2009;150:840)

For FMD (usually more distal lesions): PTA ± bailout stenting

Renal parenchymal disease: salt and fluid restriction, ± diuretics

Endocrine etiologies: see “Adrenal Disorders”

•  Pregnancy: methyldopa, labetalol, nifedipine, hydralazine; avoid diuretics;  ACEI/ARB

HYPERTENSIVE CRISES

•  Hypertensive emergency: ↑ BP → acute target-organ ischemia and damage

neurologic damage: encephalopathy, hemorrhagic or ischemic stroke, papilledema

cardiac damage: ACS, HF/pulmonary edema, aortic dissection

renal damage: proteinuria, hematuria, acute renal failure; scleroderma renal crisis

microangiopathic hemolytic anemia; preeclampsia-eclampsia

•  Hypertensive urgency: SBP >180 or DBP >120 (?110) w/ min. or no target-organ damage

Precipitants

•  Progression of essential HTN ± medical noncompliance (esp. clonidine) or Δ in diet

•  Progression of renovascular disease; acute glomerulonephritis; scleroderma; preeclampsia

•  Endocrine: pheochromocytoma, Cushing’s

•  Sympathomimetics: cocaine, amphetamines, MAO inhibitors + foods rich in tyramine

•  Cerebral injury (do not treat HTN in acute ischemic stroke unless Pt getting lysed, extreme

BP (>220/120), Ao dissection, active ischemia or HF (Stroke 2003;34:1056)

Treatment (Chest 2007;131:1949)

•  Tailor goals to clinical context (eg, more rapid lowering for Ao dissection)

•  Emergency: ↓ MAP by ~25% in mins to 2 h w/ IV agents (may need arterial line for monitoring); goal DBP <110 w/in 2–6 h, as tolerated

•  Urgency: ↓ BP in hours using PO agents; goal normal BP in ~1–2 d

•  Watch UOP, Cr, mental status: may indicate a lower BP is not tolerated