CONGRESS ABSTRACT

The formation of amyloidogenic fibrils from transthyretin can be caused by genetic mutations that alter the protein structure, but it can also occur from originally normal tetramers that through unknown mechanisms break down into monomers that go on to be deposited predominantly at the cardiac level. Although the mechanism of this disorder is unknown, multiple epidemiological studies offer interesting observations. Relevant is the association between aortic stenosis and transthyretin wild-type amyloidosis, so much so that among patients referred for aortic valve replacement 1 in 8 turns out to have TTRw when disease screening is performed. Several hypotheses have been formulated on this correlation; the most interesting is that the increased afterload induced by aortic stenosis promotes the deposition of transthyretin fibrils in the cardiac interstitium. Materials and Methods From 2018 to the present, we have recorded the clinical, laboratory, and instrumental data of patients diagnosed with cardiac amyloidosis referred to our center. In this study, we compared the characteristics of our TTRw patient population with those of the general population of the same age and with heart failure patients with preserved ejection fraction (HFpEF), evaluating any differences with possible pathophysiological role.Results From 2018 to date, 96 TTRw diagnoses have been made in our center. The mean age of the patients is 78 years. Analysis of population characteristics revealed that 89% of patients have a history of hypertension, 19% have diabetes mellitus, 18% report active or past smoking habits, 22% have known coronary artery disease, 38% have a diagnosis of bilateral carpal tunnel, 21% are pacemaker carriers, and 40% have a history of atrial fibrillation or atrial flutter. The prevalence of hypertension appears to be significantly higher than both that of the general population aged >65 years, which is around 60%, and that reported in case histories of patients with HFpEF, which is between 60% and 80%. This finding suggests that arterial hypertension may be correlated with deposition of wtTTR fibrils at the cardiac level.Arterial hypertension, in a manner similar to aortic stenosis, conditions a chronic and continuous increase in cardiac afterload, probably configuring a setting favoring wtTTR deposition. Our observation needs to be confirmed in larger case series of TTRw at the multicenter level.