PHILADELPHIA — Left ventricular dysfunction is a powerful predictor of poor outcome in patients who have received a heart transplant.
During 13 years of follow-up of almost 19,000 patients with transplanted hearts, the cumulative rate of left ventricular (LV) dysfunction (ejection fraction of 40% or less) was 23%, Katherine Lietz, M.D., reported at the annual meeting of the International Society for Heart and Lung Transplantation.
In heart transplant patients with LV dysfunction, the relative risk of cardiac death was 2.65-fold higher than the risk in those without LV dysfunction. The risk of noncardiac death in patients with impaired LV function was almost twice that of controls, due mostly to renal dysfunction that was secondary to heart failure, said Dr. Lietz, a cardiologist at the University of Minnesota in Minneapolis.
The study used data from the U.S. Scientific Registry of Transplant Recipients for heart transplants done during 1990–2003 on 25,719 patients. Exclusion of patients who were lost to follow-up or did not survive for at least 1 year left a study group of 18,854 patients, who were followed until they died, until their transplanted hearts failed, or through May 2004.
Aside from the patients who developed heart failure, LV function stayed fairly constant through follow-up, which lasted up to 13 years. The average LV ejection fraction (EF) for the entire group was about 59% after 1 year of follow-up and 57% after 13 years. Development of heart failure occurred at a fairly constant rate, occurring in about 2% of patients a year.
The two most powerful risk factors for LV dysfunction were coronary vasculopathy and renal dysfunction; each more than doubled the risk. Other significant risk factors were African American race, which raised the risk by 89%; need for retransplantation (67%); and acute rejection (65%).
The prevalence of vasculopathy was 34% in patients with an EF of more than 40%. Among those with lower EFs, the prevalence was 57%.
The increased risk of death associated with LV dysfunction was proportional to the severity of the dysfunction. Patients with EFs of 45%–55% had a 25% higher risk of death than did patients with EFs of more than 65%. The mortality risk was 57% higher in patients with EFs of 35%–45%, and was 2.6-fold higher in those with EFs of less than 35%.