Is the prognosis poorer in heart transplanted patients who develop a right bundle branch block?

Currently studies conflict on the impact on mortality of right bundle branch block development after transplantation. Most studies conclude that right bundle branch block does not affect patient survival. However, no distinction is made between patients in whom right bundle branch block progresses and those in whom it remains unchanged during follow-up. The objective of this study is to assess clinical or survival differences between patients who develop right bundle branch block and those who do not, and also to analyze these differences depending on progression of this conduction abnormality.

Ninety-seven consecutive heart transplant recipients with more than 1 year's survival were analyzed. Twelve-lead standard ECGs were performed during the first week after transplantation, which allowed for classification of patients depending on the presence or absence of right bundle branch block. Subsequently, throughout the first year, 2 groups were identified, depending on increase of the conduction defect. The groups were compared and factors determining the presence of right bundle branch block and progression of the conduction defect were found. Survival curves for the conduction defect were also compared.

Fifty percent of the patients developed right bundle branch block after transplantation; it was progressive in 10. Progressive right bundle branch block was related to greater renal dysfunction (odds ration [OR] = 10.8; confidence interval [CI] = 2-58; p = 0.006), a larger number of rejections (p = 0.01), and a greater death rate (OR = 12.8; CI = 2.5-64; p = 0.002). The presence of progressive right bundle branch block was an independent predictor of long-term mortality (OR = 27.9; CI = 4.2-186.3; p = 0.0006).

The development of right bundle branch block after transplantation is related to intraoperative factors and to a greater number of rejections. The presence of this conduction disorder, particularly if it progresses during the first year, identifies a sub-group of patients with a poorer long-term prognosis.