What is the best management plan for a patient with Grade II diastolic dysfunction, an ejection fraction (EF) of 60-65%, mild aortic stenosis, and hypertension (HTN) who is currently on losartan (Angiotensin II receptor antagonist) 25mg daily with blood pressure (BP) at goal?

Management of Grade II Diastolic Dysfunction with Mild Aortic Stenosis and Controlled Hypertension

Continue losartan 25mg daily and add a beta-blocker (such as metoprolol succinate or carvedilol) to optimize management of diastolic dysfunction, while maintaining current blood pressure control. 1, 2

Rationale for Beta-Blocker Addition

Beta-blockers are specifically beneficial in diastolic dysfunction by prolonging diastolic filling time, reducing heart rate, and improving left ventricular relaxation. 2, 3 In patients with aortic stenosis and diastolic dysfunction, beta-blockers are well-tolerated and represent a better choice than other antihypertensive classes, particularly when there is left ventricular hypertrophy (which is present in approximately 50% of aortic stenosis patients with normal systolic function). 3, 4

• Beta-blockers are appropriate for patients with aortic stenosis who have reduced ejection fraction, prior MI, arrhythmias, or angina pectoris, but they also provide specific benefits for diastolic dysfunction independent of these conditions. 1
• The target dose for metoprolol succinate in heart failure trials was 200mg daily, which is substantially higher than doses used for hypertension (25-100mg daily), emphasizing the importance of uptitration to target doses for mortality benefit. 5
• Start with low doses (metoprolol succinate 25mg daily or carvedilol 3.125mg twice daily) and gradually titrate upward every 2-4 weeks as tolerated, monitoring for hypotension and bradycardia. 1

Why Continue Losartan

ACE inhibitors and ARBs are the preferred first-line antihypertensive agents in aortic stenosis due to their beneficial effects on left ventricular fibrosis, blood pressure control, dyspnea reduction, and improved effort tolerance. 1, 6

• Renin-angiotensin system blockers (like losartan) improve survival in aortic stenosis patients both before and after valve intervention, making them superior to other antihypertensive classes. 4
• The current dose of losartan 25mg daily is appropriate for patients with possible intravascular depletion or as a starting dose, but can be increased to 50mg or even 100mg daily if blood pressure control requires optimization. 7
• In the LIFE trial, losartan 50-100mg daily (with hydrochlorothiazide if needed) was more effective than atenolol in reducing cardiovascular events in hypertensive patients with left ventricular hypertrophy. 5

Blood Pressure Target

Maintain systolic blood pressure between 130-139 mmHg and diastolic 70-90 mmHg, as this range represents the optimal target in aortic stenosis patients based on observational evidence. 4

• Lower blood pressure targets should be avoided in aortic stenosis, as excessive blood pressure reduction can compromise cardiac output across the stenotic valve. 1, 4
• The goal blood pressure is <140/90 mmHg if tolerated, consistent with general hypertension guidelines, but the 130-139 mmHg systolic range appears optimal specifically for aortic stenosis. 5, 4

Monitoring and Surveillance

Perform echocardiography every 1-2 years for mild aortic stenosis, with careful assessment for progression of stenosis severity, left ventricular dimensions, ejection fraction, and progression of left ventricular hypertrophy. 1

• Increase echocardiography frequency to every 6 months if moderate-to-severe valve calcification develops, peak velocity exceeds 4 m/s, or rapid progression is detected (velocity progression >0.3 m/s per year). 1
• At each visit, specifically assess for exertional dyspnea, angina, dizziness, or syncope, as these symptoms indicate need for urgent valve intervention. 1
• Check renal function and electrolytes 1-2 weeks after initiating beta-blocker therapy, as the combination of ARB and beta-blocker can affect kidney function and blood pressure. 6

Critical Pitfalls to Avoid

Do not use diuretics in this euvolemic patient with mild aortic stenosis, as diuretics should be used sparingly in patients with small left ventricular chamber dimensions (common in aortic stenosis due to concentric hypertrophy). 1, 8

• Excessive diuresis can lead to critical reduction in preload, causing worsening hypotension and compromised cardiac output across the stenotic valve—a particular concern in aortic stenosis where patients are preload-dependent. 6
• Calcium channel blockers should be avoided, as they may be associated with lower survival in aortic stenosis patients. 4
• Vasodilators (including nitrates) require extreme caution in aortic stenosis, as they may cause substantial hypotension by reducing preload in patients with fixed obstruction to left ventricular outflow. 1

Uptitration Strategy

Start beta-blocker at low dose and uptitrate every 2-4 weeks toward target doses, prioritizing achievement of target doses over avoidance of minor side effects. 5

• The most dramatic decreases in blood pressure with beta-blockers occur with the initial low starting dose, and subsequent changes with each dosing increment are comparatively modest. 5
• If asymptomatic hypotension or mild worsening of renal function occurs during uptitration, these should be managed with supportive measures rather than stopping uptitration, as target doses provide superior mortality benefit. 5
• Consider cardiology co-management for ongoing optimization of medical therapy and surveillance, as recommended for patients with moderate or severe aortic stenosis. 1, 6