Enhancing prognostic evaluation in cardiac amyloidosis: PALS, GLS and functional tests beyond KCCQ

Background Cardiac amyloidosis (CA) often leads to reduced functional abilities, quality of life, and potential psychological repercussions. Several tests assess functional capacity, with the KCCQ score being the most widely used for heart failure symptoms, but it may overly rely on psychological factors. Left atrial (LA) strain indicates left ventricular (LV) diastolic function and filling pressure but doesn't correlate with KCCQ scores. The relationship between other tests and functional capacity or HRQoL (health-related quality of life) in CA remains unexplored. Objective This observational study aimed to assess the correlation between LA strain and LV global longitudinal strain (LVGLS) with functional tests. Furthermore, we aimed to examine their association with NT-proBNP levels and 6MWT in patients affected by CA, encompassing both AL and ATTR subtypes. Methods We enrolled patients with CA during their follow-up visits. They underwent clinical, echocardiographic, functional capacity and quality-of-life assessments, including the 6-minute walk test (6MWT) at baseline and after 3–6 months during follow-up visits, while subsequent clinical follow-up was used to ascertain the composite endpoint. The composite endpoint included all-cause mortality, hospitalization or emergency department visit for heart failure, and urgent cardiovascular visits for worsening heart failure symptoms. Deaths were further classified as cardiovascular or non-cardiovascular according to the predefined cause-of-death classification. Results In total, 67 patients diagnosed with CA (48 ATTRwt and 19 AL, average age 78 years, 21% female) were included. At baseline, patients had an LVEF of 53 ± 7%, a LVGLS of −13 ± 6% and mean PALS of 13 ± 7%. Global PALS demonstrated a positive correlation with DASI score ( p = 0.06) and 6MWT ( p = 0.004), and showed an inverse correlation with MLHFQ score ( p = 0.005) and NT-proBNP ( p = 0.003) while it was not correlated with KCCQ ( p = 0.21). GLS demonstrated a positive correlation with NT-proBNP ( p = 0.001), Minnesota score ( p = 0.01), DASI score ( p = 0.017). In contrast, the KCCQ did not correlate with NT-proBNP, PALS, 6MWT, or GLS. 42 patients (62.7%) experienced the composite endpoint. GLS was lower in the event group, PALS was lower, interventricular septal thickness (IVS) was larger, NT-proBNP was greater, and LAVi was higher. Our study showed that LVGLS, PALS, and apical sparing (RELAPS) were associated with the composite clinical endpoint, with LVGLS showing the numerically highest AUC among the evaluated parameters (AUC 0.704 (95% CI: 0.595–0.813) for LVGLS, 0.663 (95% CI: 0.549–0.777) for PALS, and 0.660 (95% CI: 0.545–0.775) for RELAPS). Conclusions LVGLS showed significant associations with functional status and quality-of-life measures and had the numerically highest AUC for the composite clinical endpoint among the evaluated parameters.