Cardiac Transplantation?

Cardiac Transplantation?

As of Monday, December 17, 2018, Northwestern Memorial Hospital surgeons have completed a record-breaking 54 cardiac transplants this calendar year. The hospital held a celebration to honor the transplant recipients, donors, and families. Among the attendees at the celebration were cardiac surgeons, attributing the increase in cardiac transplants to a greater number of individuals electing to be organ donors.   

There are currently about 6 million patients in the United States with heart failure.  About 300,000 are potentially eligible for cardiac transplantation.  Due to limited donor availability, the annual number of cardiac transplants are estimated to be about 4,000 procedures worldwide.

Given the great variance between organ availability and patient need, it is essential to determine which patients are medically refractory to therapy and are most in need of cardiac transplantation.  The most common indication for cardiac transplantation is intractable heart failure as manifested by severe functional limitations, refractory angina, and/or ventricular dysrhythmias refractory to medical therapy.  A more comprehensive list of commonly accepted indications for cardiac transplantation is listed here.

There are a number of absolute and relative contraindications that may prohibit patients from undergoing cardiac transplantation.  Active bacterial infections represent an absolute contraindication.  Chronic viral infections are a relative contraindication and some centers will consider transplantation in the setting of chronic hepatitis and HIV.  Most active malignancies prohibit transplantation, but patients with non-melanoma cutaneous cancers, primary cardiac tumors restricted to the heart, and low-grade neoplasms of the prostate may be considered for transplantation. Other absolute and relative contraindications include age >70, BMI >30, pulmonary hypertension, end-stage renal disease, cirrhosis, substance abuse, and psychiatric illness.

Though the list of indications and contraindications are widely accepted, identification of the subgroup of patients that qualify for cardiac transplant is a daunting task.  Patients that may benefit from cardiac transplantation should be referred to a team of cardiac transplant specialists for a complete pre-transplant evaluation. This evaluation will determine if medical therapy has been fully optimized, determine if the patient will benefit from transplantation, further assess indications and contraindications, and determine if the patient has adequate social support.  Patients also typically undergo advanced cardiopulmonary exercise testing and pulmonary artery catheterization to obtain further data points to assist in making a determination.

Patients require induction immunosuppression immediately following cardiac transplantation and then maintenance, lifelong immunosuppression.  The 1-year survival time following cardiac transplantation is ~90% with a 14-year conditional half-life. Factors that improve overall survival include receiving transplantation at higher volume center, lower allograft ischemic time, younger donor age, and younger recipient age.

Read more about cardiac transplantation:

Hursts the Heart, 14e: Chapter 72: Cardiac Transplantation

Harrison's Principles of Internal Medicine, 20e: Chapter 255: Cardiac Transplantation and Prolonged Assisted Circulation