Background: Amyloidosis is a systemic disease caused by fibrillary misfolded protein deposition in several organs including the heart. Cardiac deposition is the leading cause of death in these patients. Echocardiography is the imaging technique mostly used to study cardiac amyloidosis. Many studies tried to identify earlier markers to stratify the mortality risk. Heart stiffness is the main issue leading the heart dysfunction. However, few data are available on the possible role of connection between heart and possible vessels alterations.
Purpose: Aim of this study was to evaluate heart stiffness using Ventricular–arterial coupling (VAC) for relationship between heart and vessel tree.
Methods: We studied 58 patients (22 F and 36 M, aged 67.14± 12.49) with AL or ATTR amyloidosis and heart involvement. They were 42 AL and 16 ATTR patients. All patients were evaluated before treatment with a complete history, physical exam, serum markers of disease, and echocardiogram. The abdominal fat biopsy to confirm amyloid deposition was performed before treatment. Among all patients, 18 died with a mean OS of 12 months [IQR 1-24 months].
Results: At baseline, VAC was increased in died patients (alive 1.53 ± 0.43 vs died 2.06 ± 1.73, p=0.09) but was ineffective to predict the risk of mortality (ROC analysis AUC 0.54, p=0.57). By analysing ejection and pre-ejection periods we found that they were both increased in alive patients (p=0.0016 and p=0.0072, respectively). Moreover, these periods were effective in prediction of the death risk (ejection time AUC 0.81, cut-off 239 msec, sensitivity 61.54% and specificity 88.24%; pre-ejection time AUC 0.75, cut-off 82 msec, sensitivity 84.62% and specificity 58.82%). No difference in VAC, ejection time or pre-ejection time were found comparing AL to ATTR, nor both parameters had a predictive role.
Conclusion: Amyloidosis induces an increase in heart stiffness and reduces heart contractility. This causes a reduction of peripheral blood flow and a worsening in heart failure. We demonstrated that this mechanism affects the capacity to pump blood in vessels due the reduction in time for loading during the systole. These results may predict the mortality with a significant sensitivity and specificity, regardless of the type of amyloidosis.