Prognostic impact of SGLT2-inhibitor therapy on survival in patients with transthyretin amyloid cardiomyopathy

Abstract Background Sodium-glucose co-transporter 2 inhibitors (SGLT2i) significantly improve cardiovascular outcomes in patients with heart failure across the whole spectrum of ejection fraction. Recently published data indicates the safety and tolerability of SGLT2i therapy in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). However, there is a lack of evidence regarding the impact of SGLT2i therapy on clinical outcomes in those patients. Purpose This study aims to investigate the association between SGLT2i therapy and clinical outcomes in patients with ATTR-CM. Methods This is an analysis of a prospective registry conducted at an expert center for hypertrophic cardiomyopathies. We included all participants with a confirmed diagnosis of ATTR-CM, who were enrolled until December 2022. Prior and concomitant SGLT2i treatment was systemically assessed according to the patient interview and medical records. Patients’ outcomes were retrieved from local medical and health insurance records. Results We enrolled 116 patients, of whom 7 patients (6%) were treated with SGLT2i at inclusion and 44 patients (38%) were started on SGLT2i therapy during the observational period while 65 patients (56%) were SGLT2i-naïve. There were no significant differences in baseline characteristics between groups, as shown in the table. Median (interquartile range) age was 80 (76-82) years with 15% females. Median N-terminal pro-brain natriuretic peptide (NT-proBNP) was 2844 (1519-5033) pg/ml, median estimated glomerular filtration rate (eGFR) 58 (46-69) ml/min/1,73m2, and median troponin T 56 (34-83) pg/ml. During a median follow-up of 2.6 (1.8-3.7) years, 28 patients (24%) died, of whom 6 patients (5%) were in the treatment group and 22 patients (19%) in the control group. In univariate Cox-regression analysis, SGLT2i treatment was significantly associated with a lower mortality (HR 0.325, 95%CI 0.132-0.802, p=0.015). This association persisted after adjusting for age and sex (HR 0.347, 95%CI 0.139-0.867, p=0.023). However, when treatment initiation time was considered, the benefit did not remain statistically significant. No significant associations between SGLT2i treatment and worsening heart failure hospitalizations or cardiovascular death were observed. Conclusion In a prospective registry-based cohort of patients with ATTR-CM, SGLT2i therapy was associated with significantly better survival, with a potential treatment initiation time bias. These results suggest that SGLT2i may exert beneficial effects in patients with ATTR-CM and warrant a randomized controlled trial.