Management of Acute Aortic Disease with Vasodilators

Introduction to Vasodilator Therapy

The European Society of Cardiology recommends reducing systolic blood pressure to ≤120 mmHg and heart rate to ≤60 bpm to minimize aortic wall stress and prevent disease progression in patients with acute aortic disease, including symptomatic abdominal aortic aneurysm 1, 2.

Beta-blockers, such as esmolol, are the cornerstone of therapy and must be initiated first to prevent reflex tachycardia from vasodilators, which would increase aortic wall shear stress, and should be combined with either nitroprusside or nitroglycerin 1, 2, 3.

Intravenous nitroglycerin is an acceptable alternative vasodilator when nitroprusside is unavailable, with dosing starting at 5-20 mcg/min IV infusion and increasing by 5-10 mcg/min every 3-5 minutes as needed, with maximum doses up to 200 mcg/min 1, 2, 4, 5, 6.
The American College of Cardiology and European Heart Society guidelines list both nitroprusside and nitroglycerin as options for acute aortic disease management when combined with beta-blockade 2.

Nitroprusside has a more potent balanced vasodilator effect with both preload and afterload reduction, a faster onset, and a more predictable dose-response relationship compared to nitroglycerin 1, 4, 5, 6.
Nitroglycerin has a predominantly venodilator effect, less potent afterload reduction, and tachyphylaxis develops within 24-48 hours, requiring dose escalation 4, 5, 6, 7.

Continuous blood pressure monitoring with measurements every 3-5 minutes during titration, and continuous ECG monitoring for heart rate control are required when using vasodilators 2, 4, 5, 6.
Target systolic BP <120 mmHg and heart rate <60 bpm, and avoid precipitous drops in blood pressure that could compromise organ perfusion 1, 2, 4, 5.

Never use vasodilators alone without beta-blockade in aortic disease, as the reflex tachycardia from unopposed vasodilation increases dp/dt and dramatically increases aortic wall stress and rupture risk 1, 2.
If systolic blood pressure is <90 mmHg, vasodilators should be avoided as they may critically reduce organ perfusion, and surgical intervention may be urgently needed 4, 5, 6.