What are the complications of aortic valve replacement surgery?

Complications of Aortic Valve Replacement Surgery

The most common complications of aortic valve replacement surgery include mortality (3%), stroke (2%), prolonged ventilation (11%), thromboembolism, bleeding, and prosthetic valve dysfunction, with risk varying by patient factors and valve type. 1

Major Complications

Mortality

• Overall mortality rate is under 3% for all patients undergoing surgical AVR 1
• Risk increases significantly with:
  • Advanced age
  • Emergency surgery
  • Presence of endocarditis
  • Previous cardiac surgery
  • Multiple comorbidities
• In high-risk patients, mortality can reach 16.4% 1

Neurological Complications

• Stroke occurs in approximately 1.5-2% of patients 1
• Risk factors for stroke include:
  • Mechanical valves (higher risk than bioprosthetic)
  • Atrial fibrillation
  • Cardiomyopathy
  • Carotid stenosis
  • Aortic arch atheroma 1
• Stroke risk is highest within first 72 hours post-procedure

Bleeding and Thromboembolism

• Mechanical valves require long-term anticoagulation with warfarin
  • Annual risk of serious thromboembolism: 0.5%
  • Annual risk of major hemorrhage: 0.5% 1
• Bioprosthetic valves have lower bleeding risk but:
  • 0.7% per year risk of thromboembolism in patients with normal sinus rhythm without anticoagulation 1
  • Higher risk in first few days/months before endothelialization of the sewing ring 1

Prosthetic Valve Dysfunction

• Mechanical valves: excellent long-term durability but higher thromboembolism risk
• Bioprosthetic valves: structural valve degeneration occurs at:
  • 10-12 years in younger patients
  • 15-18 years in older patients 1
• Freedom from reoperation with modern bioprosthetic valves:
  • 95% at 5 years
  • 90% at 10 years
  • 70% at 15 years 1

Infectious Complications

• Sternal wound infection risk is under 1% for deep infection 1
• Risk factors include:
  • Diabetes
  • Obesity
  • Smoking
  • Immunosuppressive therapy
  • Prior radiation therapy 1
• Blood transfusion-related infections (hepatitis C, HIV) are now extremely rare 1

Pulmonary and Pleural Complications

• Pulmonary complications (respiratory failure, pneumonia, atelectasis) occur in about 6% of patients 2
• Pleural complications (pleural effusion, pneumothorax, hemothorax, empyema) occur in about 5% of patients 2
• Risk factors for pulmonary complications:
  • Postoperative heart failure (OR 4.7)
  • Previous pacemaker implant (OR 4.4)
  • Chronic obstructive pulmonary disease (OR 1.7) 2
• Risk factors for pleural complications:
  • Postoperative bleeding (OR 7.4)
  • Carotid artery disease (OR 2.8)
  • Previous coronary artery surgery (OR 2.7)
  • COPD (OR 1.9)
  • Cardiac conduction defect (OR 1.9) 2

Other Organ System Complications

• Renal failure
• Hepatic dysfunction
• Gastrointestinal complications 1
• Cardiac conduction abnormalities requiring pacemaker

Special Considerations by Patient Population

Elderly Patients

• Despite higher baseline risk, carefully selected octogenarians can safely undergo AVR with a 2% incidence of stroke 1
• Quality of life after AVR in patients >80 years is comparable to the general population >75 years 3
• Risk factors for late mortality in elderly include:
  • Preoperative or perioperative stroke
  • COPD
  • Aortic stenosis (vs. regurgitation)
  • Postoperative renal dysfunction 3

Female Patients

• Women have higher mortality, stroke rate, and longer postoperative stays 4

Patients with Poor Left Ventricular Function

• Ejection fraction <30% is associated with higher mortality, stroke rate, and longer postoperative stay 4

Transcatheter Aortic Valve Replacement (TAVR) Complications

While not the primary focus of the question, it's worth noting TAVR has its own complication profile:

• Mortality: 3-5%
• Stroke: 6-7% (higher than surgical AVR)
• Access complications: 17%
• Pacemaker insertion: 2-9% (Sapien) or 19-43% (CoreValve)
• Paravalvular aortic regurgitation
• Coronary occlusion
• Valve embolization
• Aortic rupture 1, 5

Clinical Pitfalls to Avoid

1. Anticoagulation management: Carefully balance thromboembolism vs. bleeding risk based on valve type

   • Mechanical valves require long-term anticoagulation
   • Bioprosthetic valves require short-term anticoagulation or antiplatelet therapy

2. Timing of intervention: Delaying surgery in symptomatic patients with severe aortic valve disease increases mortality risk

3. Valve selection: Consider patient age, comorbidities, and anticoagulation contraindications when choosing between mechanical and bioprosthetic valves

4. Endocarditis prophylaxis: All patients with prosthetic heart valves require appropriate antibiotic prophylaxis

5. Recognition of early complications: Prompt identification of bleeding, tamponade, or stroke is essential for improving outcomes