Clinical significance of the estimation of pulmonary-right ventricular uncoupling in patients with transthyretin amyloid cardiomyopathy.

Aims: There are few data on the prognostic impact of pulmonary-right ventricular (RV) uncoupling in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM).

Methods And Results: Among the 174 patients who were diagnosed with ATTRwt-CM at Kumamoto University Hospital from 2002 to 2021, 143 patients who met the current Japanese guideline and had sufficient information for two-dimensional speckle tracking echocardiography were retrospectively analysed. During a median follow-up of 1209 days, 39 cardiac deaths occurred. Compared with patients in the non-event group, those in the cardiac death group were significantly older (79.3 ± 6.7 vs. 76.4 ± 6.2, respectively; < 0.05). Additionally, RV global longitudinal strain (RV-GLS)/systolic pulmonary artery pressure (sPAP), an index of pulmonary-RV uncoupling, was significantly lower in patients in the cardiac death group vs. the non-event group [0.29 (0.18-0.35) vs. 0.40 (0.29-0.57), < 0.01]. Multivariate Cox proportional hazards regression analysis demonstrated that RV-GLS/sPAP was significantly associated with cardiac death after adjusting for tricuspid annular plane systolic excursion/sPAP ( < 0.01), sPAP ( < 0.05), and conventional prognostic factors including age and hospitalization for heart failure (<0.01), laboratory finding including high-sensitivity cardiac troponin T, and B-type natriuretic peptide ( < 0.01). Receiver operating characteristic analysis showed that the area under the curve for RV-GLS/sPAP for cardiac death was 0.72 and that the best cut off value for RV-GLS/sPAP was 0.34 (sensitivity, 76%; specificity, 65%). In the Kaplan-Meier analysis, patients with ATTRwt-CM who had low vs. high RV-GLS/sPAP (cut-off value 0.34) had a significantly higher probability of cardiac death ( < 0.01).

Conclusion: Pulmonary-RV uncoupling has significantly higher prognostic value compared with conventional prognostic factors in ATTRwt-CM.