IDDF2024-ABS-0366 Effect of switching from prior nucleos(t)ide analogue(s) to tenofovir alafenamide on lipid profile and cardiovascular risk in patients with chronic hepatitis B

<h3>Background</h3> Tenofovir alafenamide (TAF) is recommended for chronic hepatitis B (CHB) treatment in international guidelines according to its efficacy and safety. However, in the phase III study, increased LDL-c was observed in those who were switched from Tenofovir disoproxil fumarate (TDF) to TAF. Limited data exists on whether lipid profiles change only in individuals who switched from TDF or any nucleoside/nucleotide analogues (NUC). We investigated how switching to TAF affected lipid and cardiovascular outcomes in CHB patients. <h3>Methods</h3> We conducted a prospective observational study including CHB patients who had been receiving NUC and switched to TAF (according to the national reimbursement policy in 2023) at a university hospital in Thailand. In addition to usual follow-ups, enrolled patients had lipid tests and transient elastography (TE) at 0- and 48-week post-switch. Demographic data, CHB status, liver biochemistry, controlled attenuated parameter (CAP) and liver stiffness were collected. The changes in lipid and TE results between weeks 0 and 48 were compared between those with prior TDF and other NUCs. <h3>Results</h3> A total of 79 patients who completed a 48-week follow-up were analyzed. The prior NUCs before switching were 28 TDF-based, 17 Entecavir (ETV), and 34 Lamivudine (LAM). Baseline characteristics were similar between groups except for underlying hypertension, and total cholesterol (TC) was higher in the TDF group compared to others. At 48-week, the median LDL-c changes were -2.3, -6.45, and +9.2 (p=0.003), and TC changes were -8, -6, and +13.5 (p&lt;0.001), in the ETV, LAM, and TDF-based group, respectively (figure 1, 2). Whereas the changes in weight, CAP, and liver stiffness were not significantly different. No cardiovascular events occurred in all patients, but 17.8% of the TDF group needed to start or increase statin dose, while only 8.8% and none of the LAM and ETV groups did. <h3>Conclusions</h3> Significant increases in LDL-c and TC after switching to TAF were observed only in patients with prior TDF but not with prior ETV or LAM. Careful monitoring of lipids after the switch may not be universally needed. Data regarding long-term cardiovascular outcomes are warranted.