From the Guidelines
Drugs used to reduce afterload include ACE inhibitors, ARBs, and sacubitril/valsartan, which have established benefits in improving LV remodeling and reducing afterload in patients with heart failure. According to the study by Lander et al. 1, beta-blockers, angiotensin-converting enzyme inhibitors, and sacubitril/valsartan have been shown to improve LV remodeling and reduce afterload in patients with HFrEF. Specifically, sacubitril/valsartan has demonstrated superiority over angiotensin-converting enzyme inhibitors or angiotensin receptor blocker treatment with respect to clinical outcomes and LV reverse remodeling in patients with HFrEF.
Some key points to consider when using these medications include:
- ACE inhibitors such as lisinopril and enalapril block angiotensin II formation, while ARBs like losartan block angiotensin II receptors 1
- Sacubitril/valsartan, an angiotensin receptor–neprilysin inhibitor (ARNI), has demonstrated superiority over angiotensin-converting enzyme inhibitors or angiotensin receptor blocker treatment with respect to clinical outcomes and LV reverse remodeling in patients with HFrEF 1
- Hydralazine and nitrates have unclear long-term benefits in reducing afterload, although they may be used in specific contexts, such as in African Americans with symptomatic HFrEF 1
- The use of these medications should be individualized based on patient response, and blood pressure should be monitored regularly to avoid hypotension, especially when initiating therapy or increasing doses.
It's worth noting that the 2014 AHA/ACC guideline for the management of patients with valvular heart disease recommends vasodilator therapy in the acute management of patients with severe decompensated AS with NYHA class IV HF symptoms, but this should be done with invasive hemodynamic monitoring 1. However, the most recent and highest quality study 1 suggests that ACE inhibitors, ARBs, and sacubitril/valsartan are the preferred medications for reducing afterload in patients with heart failure.
From the FDA Drug Label
Amlodipine is a peripheral arterial vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure... In patients with exertional angina, amlodipine reduces the total peripheral resistance (afterload) against which the heart works and reduces the rate pressure product, and thus myocardial oxygen demand, at any given level of exercise The drug used to reduce afterload is amlodipine, a calcium channel blocker that acts as a peripheral arterial vasodilator, reducing peripheral vascular resistance and blood pressure 2.
- Key benefits: reduces total peripheral resistance (afterload) and myocardial oxygen demand
- Main mechanism: acts directly on vascular smooth muscle to cause vasodilation
From the Research
Drugs to Reduce Afterload
The following drugs are used to reduce afterload:
- Angiotensin-converting enzyme (ACE) inhibitors, such as captopril and enalapril, which inhibit the renin-angiotensin-aldosterone system and cause vasodilation 3, 4
- Direct vasodilators, such as hydralazine, which decrease afterload and improve cardiac output 5, 6
- Angiotensin II receptor antagonists, such as candesartan and valsartan, which have haemodynamic effects similar to ACE inhibitors but differ in their mechanism of action and certain adverse effects 7
- Nitroprusside, which produces balanced arterial and venous dilation 5
- Prazosin, which produces balanced arterial and venous dilation 5
- Phentolamine, which produces balanced arterial and venous dilation 5
Mechanism of Action
These drugs reduce afterload by:
- Inhibiting the renin-angiotensin-aldosterone system, which causes vasoconstriction 3
- Causing vasodilation, which decreases peripheral resistance and afterload 3, 5, 6
- Decreasing cardiac preload and wall tension, which reduces afterload 6
Clinical Use
These drugs are used to treat: