Critical Care Medicine-Neurologic Disorders>>>>>Mechanical Circulatory Support and the Transplanted Heart
Question 3#

A 43-year-old woman is admitted to the ICU with palpitations and dyspnea because she is 10 weeks from successful orthotopic heart transplantation for severe idiopathic dilated cardiomyopathy. Her posttransplant course has been uneventful thus far. On admission her:

• blood pressure is 107/62
• heart rate is 113
• oxygen saturation is 88% on room air
• temperature is 37.9°C

Her physical examination is notable for:

• bibasilar rales
• an elevated jugular venous pressure
• mild pitting pedal edema

Her cardiac examination reveals:

• a rapid, irregularly irregular heart rate
• a II/VI holosystolic murmur loudest at the right lower sternal border

A 12-lead ECG shows rapid atrial fibrillation.

Which of the following is the next best diagnostic test to obtain in the management of this patient?

A. Endomyocardial biopsy
B. Two sets of sterile blood cultures
C. Transesophageal echocardiogram
D. Coronary angiography
E. Cardiac MRI

Correct Answer is A

Comment:

Correct Answer: A

This patient is presenting with new atrial fibrillation as well as signs and symptoms of heart failure, which in a patient with a recent cardiac transplant is highly concerning for acute cardiac allograft rejection. Any suspicion for acute rejection should prompt an urgent evaluation with an endomyocardial biopsy to try and establish the diagnosis. Echocardiography is not specific for diagnosing rejection. Although cardiac MRI may be used as a screening tool, endomyocardial biopsy still remains the gold standard for diagnosis of allograft rejection. Coronary allograft vasculopathy or coronary artery disease may be diagnosed with coronary angiography but typically occurs years after transplantation. 

The incidence of any rejection in the first year after transplant reaches 25%, and the incidence of rejection requiring treatment is reported to be about 13%. The risk of developing acute rejection is much higher early after transplant, peaking at one month posttransplant and declining thereafter. Clinical symptoms of acute rejection are typically related to left ventricular systolic dysfunction and can include dyspnea, orthopnea, paroxysmal nocturnal dyspnea, peripheral edema, and gastrointestinal symptoms. Importantly, acute cellular rejection can present with atrial arrhythmias including both atrial fibrillation and atrial flutter. Once a diagnosis is made, the type of treatment varies based on histologic criteria as well as the presence of symptoms and/or hemodynamic compromise. In general, oral or intravenous corticosteroids and antithymocyte globulin are the mainstays of acute rejection therapy.

Reference:

1. Lund LH, Edwards LB, Kucheryavaya AY, et al. The registry of the International Society for Heart and Lung Transplantation: thirty-first official adult heart transplant report–2014; focus theme: retransplantation. J Heart Lung Transplant. 2014;33:996.