USMLE Step 3 Quiz: Hypertension And Vascular Disease

What this quiz covers

This quiz focuses on Hypertension And Vascular Disease, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 3.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Order a renal artery Doppler ultrasound
2. Order a 24-hour urine collection for metanephrines
3. Measure plasma aldosterone concentration and plasma renin activity (correct answer)
4. Perform an overnight low-dose dexamethasone suppression test

Explanation: This patient has resistant hypertension, defined as uncontrolled blood pressure despite the use of three antihypertensive agents from different classes, including a diuretic. The presence of mild hypokalemia in this setting is highly suggestive of primary aldosteronism, the most common cause of secondary hypertension. Therefore, the most appropriate next step is to screen for this condition by measuring plasma aldosterone concentration and plasma renin activity. An aldosterone-to-renin ratio is then calculated to make the diagnosis.

Question 2

1. Reduce mean arterial pressure by 10-20% in the first hour (correct answer)
2. Reduce systolic blood pressure to less than 140 mmHg within the first hour
3. Administer oral clonidine and transfer to an observation unit
4. Normalize blood pressure gradually over the next 48 hours

Explanation: This patient is presenting with a hypertensive emergency, characterized by severe hypertension and evidence of end-organ damage (hypertensive encephalopathy with confusion and papilledema). The initial goal of management is to carefully lower the blood pressure to prevent further organ damage without causing cerebral hypoperfusion. The standard recommendation is to lower the mean arterial pressure (MAP) by no more than 10-20% in the first hour, and then by another 5-15% over the next 23 hours. Rapidly lowering the blood pressure to normal or near-normal levels can precipitate ischemic injury.

Question 3

1. Initiation of high-intensity statin therapy (correct answer)
2. Initiation of cilostazol for symptom improvement
3. Addition of clopidogrel for dual antiplatelet therapy
4. Referral for prophylactic right popliteal artery angioplasty

Explanation: This patient has symptomatic peripheral artery disease (PAD). PAD is considered a coronary artery disease risk equivalent, and patients are at very high risk for myocardial infarction, stroke, and cardiovascular death. The cornerstone of medical management is aggressive cardiovascular risk factor modification. All patients with PAD should be on high-intensity statin therapy (e.g., atorvastatin 40-80 mg or rosuvastatin 20-40 mg) regardless of their baseline LDL-cholesterol level to reduce this risk. Cilostazol is used for symptom relief of claudication but does not reduce cardiovascular events. Dual antiplatelet therapy is not routinely recommended for stable PAD. Intervention is reserved for lifestyle-limiting symptoms refractory to medical therapy or for critical limb ischemia.

Question 4

1. Referral for right carotid endarterectomy
2. Referral for right carotid artery stenting
3. Add clopidogrel to her current aspirin regimen
4. Continue current optimal medical therapy alone (correct answer)

Explanation: The management of asymptomatic carotid stenosis is controversial, and the benefit of intervention (carotid endarterectomy [CEA] or stenting) is small and diminishes with advanced age, particularly in women. The primary management strategy is optimal medical therapy, which includes antiplatelet agents (aspirin), high-intensity statins, and aggressive blood pressure control. Given her age, sex, and asymptomatic status, the risks of a perioperative stroke from CEA likely outweigh the potential benefits of stroke reduction compared to continuing medical therapy alone. Dual antiplatelet therapy is not indicated for stable, asymptomatic stenosis.

Question 5

1. Echocardiogram to assess for coarctation
2. CT angiography of the renal arteries (correct answer)
3. Measurement of plasma aldosterone and renin levels
4. 24-hour urinary free cortisol measurement

Explanation: The patient's presentation of severe, new-onset hypertension at a young age, particularly in a female, along with an abdominal bruit, is highly suspicious for secondary hypertension due to renal artery stenosis caused by fibromuscular dysplasia (FMD). FMD is a non-atherosclerotic, non-inflammatory vascular disease that most commonly affects the renal and internal carotid arteries. CT angiography or MR angiography of the renal arteries is the preferred non-invasive imaging modality to visualize the characteristic 'string of beads' appearance of FMD.

Question 6

1. Discontinue lisinopril and start amlodipine
2. Discontinue lisinopril and start losartan (correct answer)
3. Decrease the dose of lisinopril to 20 mg daily
4. Add hydrochlorothiazide 12.5 mg daily

Explanation: The patient is experiencing a classic ACE inhibitor-induced cough. This side effect is due to the accumulation of bradykinin and is not dose-dependent. Given his comorbidities of diabetes and chronic kidney disease, continued blockade of the renin-angiotensin-aldosterone system (RAAS) is indicated for its reno- and cardioprotective benefits. The most appropriate management is to switch from an ACE inhibitor (lisinopril) to an angiotensin II receptor blocker (ARB) like losartan. ARBs do not affect bradykinin levels and are therefore not associated with cough, while providing similar RAAS blockade benefits.

Question 7

1. A widened mediastinum
2. Cardiomegaly with a 'boot-shaped' heart
3. Notching of the inferior border of the ribs (correct answer)
4. Prominent pulmonary vascular markings

Explanation: The patient's presentation, including upper extremity hypertension, diminished lower extremity pulses (brachial-femoral delay), and symptoms of leg claudication, is classic for coarctation of the aorta. In this condition, chronic aortic obstruction leads to the development of collateral circulation through the intercostal and internal mammary arteries to bypass the stenosis. The enlarged, pulsatile intercostal arteries cause pressure erosion on the inferior surfaces of the ribs, leading to the characteristic finding of rib notching on chest radiography.

Question 8

1. Drug X reduces the risk of limb-related events but not cardiovascular events in patients with symptomatic PAD. (correct answer)
2. Drug X should be the new standard of care for all patients with PAD to prevent heart attack and stroke.
3. The results are not clinically significant because the hazard ratio for MACE was not statistically significant.
4. The study demonstrates that Drug X is superior to placebo for preventing the composite primary endpoint.

Explanation: The abstract shows that the composite primary endpoint was met (statistically significant reduction). However, when breaking down the composite endpoint, the benefit was driven entirely by a reduction in major adverse limb events (MALE), as the hazard ratio for major adverse cardiovascular events (MACE) was not statistically significant. Therefore, the most accurate conclusion is that Drug X reduces limb-related events but was not shown to reduce MACE (MI, stroke, cardiovascular death). Choice D is true, but A is more specific and accurately describes the components of the outcome. Choice B is an overstatement, and Choice C incorrectly dismisses the significant primary endpoint result.

Question 9

1. Fibromuscular dysplasia
2. Giant cell arteritis
3. Takayasu arteritis (correct answer)
4. Polyarteritis nodosa

Explanation: This patient's presentation is classic for Takayasu arteritis, a large-vessel vasculitis that primarily affects the aorta and its major branches. It typically occurs in women younger than 50, often of Asian descent. The clinical picture includes systemic constitutional symptoms (fever, fatigue), evidence of vascular inflammation (elevated ESR), and signs of vessel stenosis such as blood pressure discrepancies between limbs, arterial bruits, and limb claudication. Giant cell arteritis affects patients >50. FMD does not cause systemic inflammation. Polyarteritis nodosa is a medium-vessel vasculitis that typically spares the aorta.

Question 10

1. Hydrochlorothiazide
2. Losartan (correct answer)
3. Lisinopril
4. Atenolol

Explanation: This question requires selecting an antihypertensive agent based on its effect on a comorbid condition. Among the angiotensin II receptor blockers (ARBs), losartan has a unique uricosuric effect, meaning it increases the urinary excretion of uric acid and can lower serum uric acid levels. This makes it a particularly good choice for patients with both hypertension and gout. In contrast, thiazide diuretics like hydrochlorothiazide are known to increase serum uric acid and can precipitate gout flares. While ACE inhibitors and beta-blockers are options for hypertension, they do not offer the specific benefit for hyperuricemia that losartan does.

Question 11

1. Less than 120/80 mmHg
2. Less than 130/80 mmHg (correct answer)
3. Less than 140/90 mmHg
4. Less than 150/90 mmHg

Explanation: The 2017 ACC/AHA guidelines redefined hypertension and established new treatment goals. For adults with confirmed hypertension and known cardiovascular disease or a 10-year atherosclerotic cardiovascular disease (ASCVD) risk of 10% or higher, a blood pressure target of less than 130/80 mmHg is recommended. For adults without these risk factors, a target of <130/80 mmHg may be reasonable. The previous JNC8 guideline recommended <140/90 mmHg for this patient, and <150/90 mmHg for patients over 60, making these common but outdated distractors. A goal of <120/80 mmHg is generally not recommended as a target, although it was a goal in the SPRINT trial for a specific high-risk population.

Question 12

1. Immediate referral to vascular surgery for consideration of repair
2. Repeat ultrasound surveillance in 6 months
3. Repeat ultrasound surveillance in 12 months (correct answer)
4. Repeat ultrasound surveillance in 3 years

Explanation: The management of abdominal aortic aneurysms (AAAs) is guided by their size. Elective repair is generally recommended for asymptomatic aneurysms ≥5.5 cm in men, or for those that demonstrate rapid expansion (>0.5 cm in 6 months or >1 cm in a year). For smaller aneurysms, surveillance with ultrasound is recommended. According to current guidelines, for an aneurysm measuring 4.0-4.9 cm, repeat ultrasound surveillance in 12 months is the appropriate interval. Surveillance every 6 months is for aneurysms 5.0-5.4 cm, and every 2-3 years is for those 3.0-3.9 cm.

Question 13

1. Intravenous hydralazine
2. Intravenous esmolol (correct answer)
3. Intravenous nitroglycerin
4. Oral nifedipine

Explanation: In a patient with suspected acute aortic dissection, the immediate goals are to reduce aortic shear stress by controlling both heart rate and blood pressure. The rate of rise of the aortic pressure (dP/dt) is a major determinant of aortic wall stress, and this is directly related to heart rate. Therefore, heart rate control must be established before blood pressure control. Intravenous beta-blockers, such as esmolol or labetalol, are the first-line agents. Vasodilators like hydralazine or nitroglycerin should not be used alone as they can cause reflex tachycardia, which would increase shear stress and potentially worsen the dissection.

Question 14

1. Afferent arteriolar vasoconstriction
2. Efferent arteriolar vasodilation (correct answer)
3. Direct proximal tubular toxicity
4. Drug-induced acute interstitial nephritis

Explanation: This patient with extensive atherosclerotic disease likely has underlying bilateral renal artery stenosis. In this condition, glomerular filtration rate (GFR) is maintained by angiotensin II-mediated vasoconstriction of the efferent arteriole. Initiating an ACE inhibitor (ramipril) blocks the production of angiotensin II, leading to vasodilation of the efferent arteriole. This causes a precipitous drop in intraglomerular pressure and a subsequent sharp decline in GFR, manifesting as acute kidney injury. Afferent arteriolar vasoconstriction is a mechanism of NSAID-induced AKI.

Question 15

1. Abdominal CT scan to visualize the adrenal glands
2. Measurement of plasma free metanephrines (correct answer)
3. Measurement of serum TSH and free T4
4. Renal artery Doppler ultrasound

Explanation: The patient's history of paroxysmal symptoms (headache, sweating, palpitations) combined with a severe hypertensive crisis triggered by anesthesia is highly suggestive of a pheochromocytoma. The initial step in diagnosis is biochemical confirmation of catecholamine excess. Measurement of plasma free metanephrines or 24-hour urinary fractionated metanephrines and catecholamines are the screening tests with the highest sensitivity. Anatomic imaging with CT or MRI should only be performed after biochemical evidence confirms the diagnosis, in order to locate the tumor.

Question 16

1. Obtain an urgent CT angiogram of the lower extremities
2. Administer a bolus of systemic intravenous alteplase
3. Obtain an emergent vascular surgery consultation (correct answer)
4. Admit to the medical ward for continued anticoagulation and observation

Explanation: This patient has acute limb ischemia, likely from an arterial embolism from her untreated atrial fibrillation. This is a vascular emergency. The presence of motor and sensory deficits indicates a threatened limb (Rutherford class IIb), which requires immediate intervention to prevent irreversible tissue damage and amputation. After starting systemic anticoagulation with heparin, the most critical next step is an emergent consultation with vascular surgery for revascularization, which may involve catheter-directed thrombolysis or surgical embolectomy. Delaying this consultation for imaging could compromise limb viability. Time is tissue.

Question 17

1. Administer intravenous labetalol (correct answer)
2. Administer intravenous hydralazine
3. Place a transdermal nitroglycerin patch
4. Request an order to crush his home amlodipine tablet

Explanation: This patient has acute postoperative hypertension and is NPO, requiring parenteral medication. Intravenous labetalol is an excellent choice as it is a mixed alpha- and beta-blocker that lowers blood pressure without causing significant reflex tachycardia. Intravenous hydralazine is a direct vasodilator that can cause reflex tachycardia and is less predictable, making it a second-line option. Nitroglycerin is primarily a venodilator and is not a first-line agent for hypertension without active myocardial ischemia. Crushing oral medications is often not appropriate in the immediate postoperative period when gut motility is uncertain and the patient is NPO.

Question 18

1. Contrast-induced nephropathy
2. Acute interstitial nephritis
3. Cholesterol crystal embolization (correct answer)
4. Renal artery thrombosis

Explanation: This patient's presentation is classic for cholesterol crystal embolization syndrome (atheroembolism), a complication of angiography or vascular surgery in patients with severe atherosclerosis. Manipulation of the aorta can dislodge cholesterol crystals that embolize to small arteries. The classic triad includes acute or subacute renal failure, livedo reticularis (the described rash), and peripheral eosinophilia. The timing of onset, typically weeks after the inciting procedure, helps distinguish it from contrast-induced nephropathy, which occurs within days.

Question 19

1. Admit the patient to the hospital for intravenous antihypertensive therapy
2. Send the patient to the emergency department for immediate evaluation
3. Administer a dose of oral clonidine in the office and observe for 2 hours
4. Reinstate his home oral medications and arrange a follow-up visit in 2-3 days (correct answer)

Explanation: This patient has severe asymptomatic hypertension, also known as hypertensive urgency. There is no evidence of acute end-organ damage. The most appropriate management is to reinstate his usual oral antihypertensive medications and ensure close follow-up in a few days to assess the response. Aggressive, acute lowering of blood pressure with parenteral agents or potent oral agents like clonidine in the office is not necessary and can be harmful, potentially causing hypoperfusion. Admission to the hospital or referral to the emergency department is not indicated for asymptomatic severe hypertension.

Question 20

1. Amlodipine
2. Aspirin
3. Lisinopril
4. Metoprolol (correct answer)

Explanation: Medical therapy to slow the rate of expansion of thoracic aortic aneurysms, particularly in patients with connective tissue disorders like Marfan syndrome, is crucial. The primary goal is to reduce aortic wall shear stress. Beta-blockers, such as metoprolol or atenolol, are considered first-line therapy as they decrease the rate of pressure change in the aorta (dP/dt) by reducing heart rate and contractility. Angiotensin II receptor blockers (ARBs) are also used, often in combination with beta-blockers. ACE inhibitors and calcium channel blockers have not been shown to be as effective in this specific context. Aspirin has no role in slowing aneurysm growth.