Study population
A total of 40,409 LT (21,790 in the DAA era) were performed between Jan 2007 and June 2018. Of these, 21,110 LT (9432 in the DAA era) were performed for HCV, 11,713 (7240 in the DAA era) for ALD, and 7586 (5118 in the DAA era) for NASH (Table 1). A total of 267 LT (206 in the DAA era) among recipients with ALD were performed because of a primary indication of alcoholic hepatitis (AH), with a higher proportion in the DAA era versus the pre-DAA era (2.9% vs. 1.4%, p<0.001). Overall, about 25% of LT (n=9975) were performed for liver disease complicated by HCC, with no significant differences between DAA and pre-DAA eras (p=0.75). Among the HCC LT recipients, 7786 LT (4008 in the DAA era) were performed for HCV, 1151 (629 in the DAA era) for ALD, and 958 (648 in the DAA era) for NASH (Table 2). Etiology-specific change on concomitant HCC in the DAA era showed a significant increase for HCV (43% vs. 32%, p<0.001), decrease for ALD (9% vs. 12%, p<0.001), and no change for NASH (13% vs. 13%, p=0.9).
Table 1.Baseline characteristics of all liver transplant recipients: DAA (2013-18) versus pre-DAA (2007-2012) eras
| HCV (n=21,110) | NASH (n=7586) | ALD (n=11,713) | Total (n=40,409) |
Pre-DAA (11,678, 55%) | DAA (9432, 45%) | p | Pre-DAA (2468, 33%) | DAA (5118, 67%) | p | Pre-DAA (4473, 38%) | DAA (7240, 62%) | p | Pre-DAA (18,619, 46%) | DAA (21,790, 54%) | p |
Age in years (mean, SD) | 55, 7 | 58, 7 | <0.001 | 59, 8 | 60, 8 | <0.001 | 55, 9 | 53, 10 | <0.001 | 55, 8 | 57, 9 | <0.001 |
% Female | 26 | 26 | 0.88 | 44 | 46 | 0.23 | 22 | 25 | 0.002 | 27 | 30 | <0.001 |
% C, B, H | 62,11, 24 | 61, 12, 24 | <0.001 | 78, 2, 18 | 75, 2, 20 | <0.001 | 71, 3, 24 | 69, 3, 25 | 0.004 | 66, 8, 24 | 67, 7, 23 | 0.95 |
% Obese | 36 | 35 | 0.47 | 65 | 60 | <0.001 | 35 | 35 | 0.34 | 39 | 41 | <0.001 |
% Diabetic | 24 | 25 | <0.02 | 57 | 59 | 0.22 | 24 | 20 | <0.001 | 28 | 31 | <0.001 |
% On dialysis | 11 | 14 | <0.001 | 14 | 19 | <0.001 | 17 | 23 | <0.001 | 13 | 18 | <0.001 |
% ACLF | 32 | 31 | <0.1 | 38 | 41 | 0.003 | 43 | 51 | <0.001 | 36 | 40 | <0.001 |
MELD score (mean, SD) | 20, 11 | 18, 11 | <0.001 | 22, 9 | 22, 10 | 0.87 | 23, 10 | 25, 10 | <0.001 | 21, 10.5 | 21.2, 11 | <0.001 |
Wait time in days (mean, SD) | 306, 544 | 342, 565 | <0.001 | 199, 337 | 218, 360 | <0.03 | 200, 443 | 157, 343 | <0.001 | 266, 501 | 252, 453 | 0.002 |
DRI (mean, SD) | 1.55, 0.34 | 1.53, 0.35 | <0.001 | 1.61, 0.39 | 1.59, 0.37 | <0.02 | 1.61, 0.39 | 1.57, 0.36 | <0.001 | 1.57, 0.36 | 1.56, 0.36 | <0.001 |
Table 2.Baseline characteristics of recipients for hepatocellular carcinoma: DAA (2013-18) versus pre-DAA (2007-2012) eras
| HCV (n=7786) | NASH (n=958) | ALD (n=1151) | Total (n=9975) |
Pre-DAA (3778, 49%) | DAA (4008, 51%) | p | Pre-DAA (310, 32%) | DAA (648, 68%) | p | Pre-DAA (522, 45%) | DAA (629, 55%) | p | Pre-DAA (4610, 46%) | DAA (5365, 54%) | p | |
Age in years (mean, SD) | 57, 6 | 61, 6 | <0.001 | 62, 6 | 64, 6 | <0.001 | 59, 8 | 61, 8 | <0.001 | 58, 6 | 61, 6 | <0.001 | |
% Female | 22 | 21 | 0.45 | 37 | 35 | 0.56 | 12 | 10 | 0.4 | 22 | 21 | 0.87 | |
% C, B, H | 60, 10, 26 | 59, 12, 24 | <0.001 | 75, 1, 20 | 70, 1, 25 | 0.35 | 63, 2, 30 | 64, 4, 30 | <0.03 | 62,8,26 | 61,5,13 | 0.43 | |
% Obese | 35 | 35 | 0.87 | 66 | 61 | 0.13 | 38 | 40 | 0.61 | 38 | 38 | 0.25 | |
% Diabetic | 25 | 27 | 0.04 | 68 | 73 | 0.14 | 37 | 35 | 0.59 | 29 | 34 | <0.001 | |
% On dialysis | 2.5 | 3.2 | 0.049 | 2.9 | 4.5 | 0.25 | 2.5 | 3.2 | 0.49 | 2.5 | 3.4 | 0.012 | |
MELD score (mean, SD) | 11.5, 7.5 | 10.7, 7.8 | <0.001 | 12.4, 6.5 | 12.8, 8.1 | 0.39 | 13, 7 | 12.4, 8 | 0.21 | 12, 7 | 11, 8 | <0.001 | |
Wait time in days (mean, SD) | 386, 618 | 426, 587 | <0.004 | 292, 445 | 371, 436 | <0.01 | 484, 729 | 459, 623 | 0.53 | 390, 622 | 423, 578 | <0.008 | |
DRI (mean, SD) | 1.55, 0.35 | 1.54, 0.35 | 0.15 | 1.65, 0.4 | 1.60, 0.39 | <0.08 | 1.61, 0.38 | 1.61, 0.37 | 0.93 | 1.56, 0.36 | 1.55, 0.36 | 0.19 | |
Baseline characteristics of LT recipients in the DAA era versus pre-DAA era
Demographics: Overall, in the DAA era, as compared to the pre-DAA era, LT recipients were older (57 vs. 55 years, p<0.001). This was more apparent for HCV (58 vs. 55 years, p<0.001) and NASH (60 vs. 59 years, p<0.001) cases. However, LT recipients with ALD were younger in the DAA era (53 vs. 55 years, p<0.001). Similarly, more females received LT in the DAA era (30% vs. 27%, p<0.001). These female LTs were mainly contributed by ALD (25% vs. 22%, p=0.002), with no gender differences for HCV- and NASH-related transplants. There were no racial differences between the two eras. However, in the DAA era, more minorities (Blacks, Hispanics, and other races) received LT because of NASH (25% vs. 22%, p<0.001) and ALD (31% vs. 29%, p=0.004) indications.
Among HCC transplants: Within the HCC transplant subgroup, recipients were older (61 vs. 58 years, p<0.001). There were no gender differences for any of the etiologies. Although there was no overall racial difference, in the DAA era, HCV-related LTs were more often performed for minorities (41% vs. 40%, p<0.001).
Comorbidities: Patients in the DAA era were more often obese (41% vs. 39%, p<0.001), diabetic (31% vs. 28%, p<0.001), and in need of dialysis (18% vs. 13%, p<0.001) versus the pre-DAA era. In the DAA era, the proportion of obese recipients decreased for NASH (60% vs. 65%, p<0.001), without any change for the other two indicators. In contrast, in the DAA era, diabetes was a more frequent comorbidity for HCV (25% vs. 24%, p<0.02), less frequent comorbidity for ALD (20% vs. 24%, p<0.001), and, although there appeared to be an increasing trend, there was no statistical difference in NASH (59% vs. 57%, p=0.22). The use of dialysis was more frequent in the DAA era for all etiologies (14% vs. 11% for HCV, 19% vs. 14% in NASH, and 23% vs. 17% in ALD, p<0.001).
Among HCC transplants: The frequency of obesity was similar for all etiologies. However, diabetes (34% vs. 29%, p<0.001) and use of dialysis (3.4% vs. 2.5%, p=0.012) were more frequent in the DAA era versus the pre-DAA era, especially among LT for HCV that were HCC-related.
Transplant characteristics: The mean MELD score at LT was higher in the DAA era (21.2 vs. 21, p<0.001). This change was mainly contributed by ALD (25 vs. 23, p<0.001). There was no statistical difference in NASH (22 vs. 22, p=0.87) and a decrease in MELD among HCV-related (18 vs. 20, p<0.001) LT. Similarly, LT was more often performed for ACLF in the DAA era (40% vs. 36%, p<0.001). The etiology-specific proportion of ACLF showed an increase for ALD (51% vs 43%, p<0.001) and NASH (41% vs. 38%, p=0.003) without there being a significant difference for HCV (31% vs. 32%, p=0.1). Within ALD etiology, as compared to the pre-DAA era, the proportion of LT for ACLF 2 and 3 (severe ACLF) and for AH was more frequent in the DAA era (36% vs. 26% and 2.9% vs. 1.4%, respectively, p<0.001). Overall, the mean wait time on the LT list was 2 weeks shorter in the DAA era (252 vs. 266 days, p=0.002). The wait time was primarily contributed by ALD etiology (157 vs. 200 days, p<0.001). In the DAA era, LT recipients with NASH (342 vs. 306 days, p<0.001) and HCV (218 vs. 199 days, p<0.03) waited longer. Overall, a better quality graft was used in the DAA era with a DRI mean lower than in the pre-DAA era (1.56 vs. 1.57, p<0.001). This was observed for all the etiologies (1.53 vs. 1.55 for HCV, 1.59 vs. 1.61 for NASH, and 1.57 vs. 1.61 for ALD, p<0.02).
Among HCC transplants: The mean MELD score was lower in the DAA era (11 vs. 12, p<0.001), mainly for LT recipients with HCV-related HCC (10.7 vs. 11.5, p<0.001). There were not mean differences for the other two indicators. In the DAA era, LT recipients with HCC waited a month longer (423 vs. 390 days, p<0.008), mainly for HCV (426 vs. 386 days, p<0.004) and NASH (371 vs. 292 days, p<0.01) cases. There were no differences for ALD cases (459 vs. 484 days, p=0.53). In the DAA era, although graft quality was better, with a mean DRI lower for all etiologies, the results were not significant (1.55 vs. 1.56, p=0.19), probably due to a small sample size compared to when analyses were performed for all LT.