New heart scan predicts survival in rare amyloidosis patients
Researchers identified a PET imaging measure that can predict which cardiac amyloidosis patients will survive longer, offering doctors a tool to better assess disease severity. The finding could help pharmaceutical companies developing amyloidosis treatments design more targeted trials and enable cardiologists to identify high-risk patients earlier.
Originaltitel: Outcome prediction by myocardial external efficiency from <sup>11</sup>C-acetate positron emission tomography in cardiac amyloidosis
<p>Aims</p><p>This study aimed to study the prognostic value of myocardial oxygen consumption (MVO<sub>2</sub>) and myocardial external efficiency (MEE) from <sup>11</sup>C-acetate positron emission tomography (PET) in cardiac amyloidosis (CA) patients.</p><p>Methods and results</p><p>Forty-eight CA patients, both transthyretin (ATTR) and immunoglobulin light chain (AL) amyloidosis, and 20 controls were included. All subjects were examined with <sup>11</sup>C-acetate PET and echocardiography. MVO<sub>2</sub>, forward stroke volume (FSV), and left ventricular mass (LVM) were derived from <sup>11</sup>C-acetate PET and used to calculate MEE. CA patients were followed for survival and the prognostic impact of clinical, echocardiographic, and <sup>11</sup>C-acetate PET parameters was analysed. MVO<sub>2</sub> and MEE were reduced in CA compared with controls, but without significant difference between deceased and surviving CA patients. The ratio of <sup>11</sup>C-acetate PET-derived FSV and LVM was also reduced in CA and significantly lowered in deceased patients compared with survivors. In univariate analysis, New York Heart Association class, N-terminal pro-brain natriuretic peptide, and the <sup>11</sup>C-acetate PET parameters FSV/LVM and MEE were the strongest prognostic factors. Of the <sup>11</sup>C-acetate PET parameters, FSV/LVM was the strongest survival predictor with hazard ratio of 0.56 per 0.1 mL/g (95% confidence interval 0.39–0.81, <em>P</em> = 0.002) and independently prognostic in a multivariate model. MEE significantly separated deceased from surviving CA patients with the cut-off of 15.7% (<em>P</em> = 0.032). Survival was significantly shorter with FSV/LVM below 0.27 mL/g (<em>P</em> < 0.001), also when separating AL- and ATTR-CA.</p><p>Conclusions</p><p>Reduced MEE was associated with shorter survival in CA patients, but FSV/LVM was the strongest survival predictor and the only independently prognostic <sup>11</sup>C-acetate PET parameter in multivariate analysis.</p>