Cardiac Allograft Vasculopathy

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Diffuse, concentric coronary artery narrowing on angiography due to a panarteritis

  • Maximal intimal thickness on intravascular ultrasound > 0.5 mm

  • Angina pectoris rare due to denervation of the allograft

GENERAL CONSIDERATIONS

• Incidence is 8% at 1 year, 30% at 5 years, and 50% at 10 years

• It is the main cause of late posttransplantation deaths and is the main factor limiting long-term survival

• Noninvasive tests are less useful in assessing this disease

• Recipient characteristics (eg, hypertension, hyperlipidemia, insulin resistance, and cytomegalovirus infection) and donor characteristics (eg, preexisting coronary disease, donor ischemic time) may play a role

• Thought to be a form of chronic rejection, but the pathophysiology is complex

• When heart failure is present, it is more likely due to a restrictive myocardial physiology rather than left ventricular systolic dysfunction

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Dyspnea

• Sudden death

• Ventricular arrhythmia

• Angina is rare despite advanced graft vasculopathy

PHYSICAL EXAM FINDINGS

• Features of heart failure may be present

DIFFERENTIAL DIAGNOSIS

• Acute rejection

• Cytomegalovirus infection

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• No specific lab tests have proven useful

• Cardiac biomarker elevation if there is acute myocardial infarction (MI)

ELECTROCARDIOGRAPHY

• ECG may indicate acute MI

• Ventricular arrhythmias may signify allograft vasculopathy

IMAGING STUDIES

• Echocardiography may show mitral valve E/A wave amplitude ratio > 2 in restrictive cardiomyopathy

• Doppler echocardiography may show early mitral valve inflow velocity deceleration time < 150 ms in restrictive cardiomyopathy

• Dobutamine echocardiography (DSE) may offer reasonable sensitivity and specificity

• DSE may also provide prognostic value

diagnostic PROCEDURES

• Right heart catheterization evidence of restrictive cardiomyopathy:

  • – Right atrial pressure > 12 mm Hg

  • – Pulmonary capillary wedge pressure > 25 mm Hg

  • – Cardiac index < 2 L/min/m²

• Coronary angiography:

  • – The disease is diffuse and concentric and easy to miss on angiogram

  • – Diameter comparison with prior angiogram is critical in recognizing the condition

  • – Collateral vessel formation is uncommon

• Intravascular ultrasound is a promising tool for early recognition of allograft vasculopathy

TREATMENT

CARDIOLOGY REFERRAL

• All patients are usually followed by a transplantation cardiologist

HOSPITALIZATION CRITERIA

• Heart failure

• Acute MI

• Symptomatic arrhythmia

MEDICATIONS

• Pravastatin useful for prevention regardless of blood lipid levels

• Calcium blockers plus angiotensin-converting enzyme inhibitors useful for hypertension

• Vitamins C and E have shown efficacy for prevention

  • Everolimus plus cyclosporine may be better than azathioprine plus cyclosporine