Does the method of heart transplantation affect left ventricular filling?

BACKGROUND

For over 40 years now orthotopic heart transplantation (OHT) has been the treatment of choice in patients with advanced heart failure. For many years patients undergoing OHT have been treated with the classical approach involving anastomosis of the donor atria with the recipient atria resulting in a heart in which the atria are enlarged. An alternative method for OHT is the bicaval anastomosis technique, which involves connecting both of the donor's venae cavae with the recipient's venae cavae.

AIM

To assess left ventricular (LV) filling in patients undergoing OHT using the classical (biatrial) versus bicaval approach.

METHODS

We analysed 60 patients who had undergone OHT between 1 and 36 months before. Myocardial biopsy at echocardiography revealed grade 0 or 1A rejection in all the patients. All the patients were also in NYHA functional class I. The patients were divided in two groups: patients who had undergone biatrial anastomosis (Group 1, n = 40) and patients who had undergone bicaval OHT (Group 2, n = 20). In order to render the results independent of pre-OHT blood pressure values in the pulmonary circulation we assessed the values of right ventricular systolic pressure (RVSP), mean pulmonary artery pressure (PAP) and transpulmonary gradient (TPG) in all the patients before OHT. We assessed the following echocardiographic parameters: peak early filling velocity (E-wave), peak atrial filling velocity (A-wave), E-wave deceleration time, early diastolic mitral valve ring motion velocity (E'), E/E', isovolumetric relaxation time of the LV, duration of the A-wave, right atrial area and left atrial area, LV mass, LV mass index, LV end-diastolic and end-systolic dimension, and the severity of tricuspid regurgitation (TR).

RESULTS

The values of RVSP, PAP and TPG in the study groups before OHT did not differ significantly. The values of E (86.5 ± 12.5 vs. 67.3 ± 8.5; p < 0.001), E' (11.9 ± 1.1 vs. 10.9 ± 0.9; p = 0.003) and E/E' (7.4 ± 1.5 vs. 6.1 ± 0.85; p = 0.006) differed between the groups and were significantly higher in the group undergoing surgery using the biatrial approach. The duration of the A-wave was significantly longer in the group undergoing surgery using the bicaval approach (129.0 ± 5.1 vs. 136.7 ± 10.0; p = 0.001). There were no significant differences in the other parameters of LV filling. Right atrial area was significantly lower in the group undergoing surgery using the bicaval approach (19.2 ± 3.0 vs. 14.0 ± 2.0; p < 0.001). LV size, LV mass and LV mass index did not differ significantly between the groups. The lack of TR was more commonly observed in the group undergoing surgery using the bicaval approach at the limit of p = 0.05. Pacemaker implantation was required in 12 (30%) patients from the group undergoing surgery using the classical method and 2 (10%) patients from the group undergoing OHT using the bicaval approach (p = 0.04).

CONCLUSIONS

Certain echocardiographic parameters suggest a better LV filling in patients undergoing OHT using the bicaval approach. Preservation of the right atrial geometry in patients undergoing OHT using the bicaval approach plays an important role in LV filling.