What is iatrogenic aortic insufficiency?

Iatrogenic Aortic Insufficiency: Definition, Causes, and Management

Iatrogenic aortic insufficiency (AI) is a complication resulting from medical procedures that causes abnormal backflow of blood from the aorta into the left ventricle during diastole, typically occurring during cardiac procedures such as catheterization, valve interventions, or cardiac surgery. 1

Definition and Etiology

Iatrogenic AI can occur in several clinical scenarios:

1. Catheter-based coronary procedures:

   • During coronary angiography (incidence <4 per 10,000 procedures)
   • During percutaneous coronary interventions (incidence <2 per 1,000 procedures) 1
   • Most commonly results from catheter-induced injury to the vessel wall

2. Cardiac surgery:

   • Valve surgery complications
   • Aortic manipulation during procedures
   • Cannulation injuries

3. Transcatheter procedures:

   • Transcatheter aortic valve implantation (TAVI)
   • Endovascular treatment of aortic coarctation

4. Other causes:

   • Aortic endografting
   • Peripheral interventions
   • Intra-aortic balloon counterpulsation 1

Pathophysiology

Iatrogenic AI typically develops through one of these mechanisms:

• Direct valve injury: Mechanical damage to valve leaflets during procedures
• Retrograde aortic dissection: Extension of vessel wall injury into the aortic root, often from the right coronary artery ostium 1
• Valve distortion: From prosthetic valve deployment or annular manipulation
• Aortic root dilation: Secondary to procedural complications

Classification

The Dunning classification system categorizes iatrogenic aortic dissection (which can lead to AI) into three types:

• Type 1: Dissection limited to the sinuses of Valsalva
• Type 2: Dissection of the ascending aorta outside the sinuses but <40 mm from the aortic annulus
• Type 3: Dissection >40 mm from the annulus 1

Clinical Presentation

Patients with iatrogenic AI may present with:

• Often asymptomatic in mild cases
• Acute hemodynamic compromise in severe cases
• Chest pain (less common than in spontaneous dissection)
• Heart failure symptoms (dyspnea, pulmonary edema)
• Cardiogenic shock in severe cases
• New diastolic murmur

Notably, patients with iatrogenic acute aortic syndrome are often painless with correspondingly less chest or back pain compared to spontaneous dissections 1.

Diagnosis

Prompt diagnosis is crucial:

• Echocardiography: TTE or TEE to confirm presence, severity, and etiology of AI
• Short deceleration time on aortic flow velocity curve indicates rapid equilibration of aortic and LV diastolic pressures
• Early closure of mitral valve indicates markedly elevated LV end-diastolic pressure
• CT imaging: Primary approach for diagnosis of aortic dissection
• Angiography: During coronary procedures, stagnation of contrast medium at the aortic root level is characteristic 1

Management

Management depends on the severity, location, and patient's hemodynamic status:

Conservative Management

• Type 1 and 2 lesions with preserved coronary flow and small dissection may be managed conservatively 1
• Close monitoring with serial imaging

Interventional Approaches

• Coronary stenting may be considered when coronary involvement is present to seal the entry flap 1

Surgical Management

• Type 3 lesions generally require surgical intervention 1
• Acute severe AI from dissection is a surgical emergency requiring prompt intervention 1
• Avoid intra-aortic balloon counterpulsation as it is contraindicated in acute severe AI 1

Prognosis

• Historically associated with high mortality
• Recent data from the German GERAADA registry indicates mortality rates similar to those for spontaneous dissections 1
• Early recognition and appropriate management significantly improve outcomes

Prevention

• Careful technique during catheterization procedures
• Appropriate sizing of transcatheter valves
• Gentle aortic manipulation during surgery
• Awareness of risk factors: advanced age, atherosclerosis, aortic aneurysms, peripheral arterial disease 1

Follow-up

• Regular clinical assessment
• Serial imaging with CT or MRI
• Echocardiographic evaluation of valve function and ventricular dimensions
• Monitoring for signs of heart failure or progressive aortic dilation

Iatrogenic AI represents a serious complication that requires prompt recognition and appropriate management to prevent significant morbidity and mortality.