Using Hemodynamics to Define Graft Function: Do We Need It?

Purpose The evaluation of graft function after heart transplantation (HT) is made by echo and endomyocardial biopsies (EMB). In our Center, we regularly perform right heart catheterization (RHC) at every EMB, until 5 years after HT. The aim of this study is to investigate the role of RHC for defining graft function. Methods We included in this study all patients (pts) undergoing to a EMB after the first month from HT for standard monitoring or for symptoms after 5 yrs from HT in our Center in 2016-17. Data were collected at every EMB. The endpoints were the interplay between RHC, LVEF and biopsy, and the impact of RHC on 2-yrs MACE occurrence. The follow up was started after the first abnormal RHC or, if no abnormal values were found, after the last RHC performed in the observation period. Results 586 EMBs were performed in 113 pts (56.6% <1yr, 38.6% 1-5 yrs, 4.8% for symptoms >5 yrs from HT). In the routine EMBs, 3A CMR and pAMR-2 were more frequent in the first year (18.4% vs 5.8%, 2.4% vs 0.4%, p<0.05); in the unscheduled EMBs, only 10.7% were 3A while 29% were p-AMR+ (25% pAMR-1+, 4% pAMR-2). LVEF did not differ according to distance from HT, routine vs unplanned EMB or CMR grading, but it was more frequently lower in pAMR+ (65% vs 7%) (p<0.01) .RHC better correlated with EMB results, being more frequently pathologic in 1B vs 3A/3B and other grades (46% vs 39% vs 32% respectively, p=0.06) and in AMR (32% vs 51% vs 93%, p-AMR 0 vs 1 vs 2, p<0.01). LVEF was less frequently normal in pts with abnormal RHC, but 82% of pts with a pathologic RHC had normal LVEF. We established three hemodynamic phenotypes: diastolic dysfunction (high filling pressures, normal cardiac index); low cardiac index; normal values. Diastolic dysfunction was more frequent according to pAMR grading (9% vs 29% vs 50%, p=0.01); low CI was more frequent in pAMR+ vs pAMR- (12% vs 8%, p=0.01); no specific hemodynamic pattern was associated with CAV. The incidence of MACE was highest in pts with a pathologic RHC and a 1B/3A/3B, lowest in those with normal RHC and EMBs positive and intermediate in those with a negative biopsy, regardless of RHC values (37.0± 11% vs 16.5±4% vs 0%). Conclusion Hemodynamics better correlates to histology than LVEF and helps in stratifying prognosis in patients with rejection; 1B and >3A CMR can both impact prognosis; assessment of diastolic dysfunction may help in suspecting latent pAMR. Our results support the use of RHC in the complex assessment of graft function. The evaluation of graft function after heart transplantation (HT) is made by echo and endomyocardial biopsies (EMB). In our Center, we regularly perform right heart catheterization (RHC) at every EMB, until 5 years after HT. The aim of this study is to investigate the role of RHC for defining graft function. We included in this study all patients (pts) undergoing to a EMB after the first month from HT for standard monitoring or for symptoms after 5 yrs from HT in our Center in 2016-17. Data were collected at every EMB. The endpoints were the interplay between RHC, LVEF and biopsy, and the impact of RHC on 2-yrs MACE occurrence. The follow up was started after the first abnormal RHC or, if no abnormal values were found, after the last RHC performed in the observation period. 586 EMBs were performed in 113 pts (56.6% <1yr, 38.6% 1-5 yrs, 4.8% for symptoms >5 yrs from HT). In the routine EMBs, 3A CMR and pAMR-2 were more frequent in the first year (18.4% vs 5.8%, 2.4% vs 0.4%, p<0.05); in the unscheduled EMBs, only 10.7% were 3A while 29% were p-AMR+ (25% pAMR-1+, 4% pAMR-2). LVEF did not differ according to distance from HT, routine vs unplanned EMB or CMR grading, but it was more frequently lower in pAMR+ (65% vs 7%) (p<0.01) .RHC better correlated with EMB results, being more frequently pathologic in 1B vs 3A/3B and other grades (46% vs 39% vs 32% respectively, p=0.06) and in AMR (32% vs 51% vs 93%, p-AMR 0 vs 1 vs 2, p<0.01). LVEF was less frequently normal in pts with abnormal RHC, but 82% of pts with a pathologic RHC had normal LVEF. We established three hemodynamic phenotypes: diastolic dysfunction (high filling pressures, normal cardiac index); low cardiac index; normal values. Diastolic dysfunction was more frequent according to pAMR grading (9% vs 29% vs 50%, p=0.01); low CI was more frequent in pAMR+ vs pAMR- (12% vs 8%, p=0.01); no specific hemodynamic pattern was associated with CAV. The incidence of MACE was highest in pts with a pathologic RHC and a 1B/3A/3B, lowest in those with normal RHC and EMBs positive and intermediate in those with a negative biopsy, regardless of RHC values (37.0± 11% vs 16.5±4% vs 0%). Hemodynamics better correlates to histology than LVEF and helps in stratifying prognosis in patients with rejection; 1B and >3A CMR can both impact prognosis; assessment of diastolic dysfunction may help in suspecting latent pAMR. Our results support the use of RHC in the complex assessment of graft function.