Echocardiographic and clinical predictors of cardiac amyloidosis: limitations of apical sparing.

AIMS: The accuracy of an apical-sparing strain pattern on transthoracic echocardiography (TTE) for predicting cardiac amyloidosis (CA) has varied in prior studies depending on the underlying cohort. We sought to evaluate the performance of apical sparing and other TTE strain findings to screen for CA in an unselected population and determine the frequency that patients with echocardiographic concern for CA undergo evaluation for amyloidosis in clinical practice. METHODS AND RESULTS: As strain is routinely performed at our institution on all clinical TTEs, we identified all TTEs performed from 2016 through 2019 with reported concern for CA or apical sparing. We determined the performance characteristics for echocardiographic strain findings in discriminating CA including apical sparing, the ejection fraction to global longitudinal strain ratio (EF/GLS), and the septal apical-septal basal ratio (SA/SB); other clinical predictors of confirmed CA; and predictors of patients who underwent complete evaluation for CA. CA was confirmed by endomyocardial biopsy or diagnostic cardiac imaging. A total of 547 TTEs, representing 451 patients, reported concern for CA and had adequate strain for analysis. A total of 111 patients underwent complete evaluation for amyloidosis with 100 patients undergoing complete cardiac evaluation for CA. In those 100 patients, multivariable predictors of confirmed CA were age [odds ratio (OR) 3.37 per 5 years], a visual apical-sparing pattern (OR 10.85), and left ventricular ejection fraction (LVEF)/GLS > 4.1 (OR 35.37). CA was less likely in those with coronary artery disease (OR 0.04), hypertension (OR 0.18), and increased systolic blood pressure (OR 0.60 per 5 mm Hg increase). SA/SB [area under the curve (AUC) 0.72, 95% confidence interval (CI) 0.60-0.84] and LVEF/GLS (AUC 0.72, 95% CI 0.60-0.84) both had improved discrimination for CA compared with the apical-sparing ratio (AUC 0.66, 95% CI 0.54-0.79). Many patients with suggestive TTE findings did not receive an evaluation for amyloidosis. Complete evaluation was more likely with Caucasian race (OR 2.1), increased septal thickness (OR 1.4), increased body mass index (OR 1.2), and if the report specifically stated 'amyloid' (OR 1.9). Evaluations were less likely in patients with comorbidities. While hypertension reduced the likelihood of evaluating for CA, 34% of patients with CA had hypertension (>130/80 mm Hg) at time of diagnosis. CONCLUSIONS: In a broad population of patients undergoing TTE, apical sparing on strain imaging increased the likelihood of CA diagnosis but with modest sensitivity and specificity. GLS/EF ratio may be a more reliable tool to screen for CA. The low rate of complete evaluation in patients with concerning TTE findings indicates a strong need for practice improvement and enhanced disease awareness.

Targeting intracellular Staphylococcus aureus to lower recurrence of orthopaedic infection.

Staphylococcus aureus is often found in orthopaedic infections and may be protected from commonly prescribed antibiotics by forming biofilms or growing intracellularly within osteoblasts. To investigate the effect of non-antibiotic compounds in conjunction with antibiotics to clear intracellular and biofilm forming S. aureus causing osteomyelitis. SAOS-2 osteoblast-like cell lines were infected with S. aureus BB1279. Antibiotics (vancomycin, VAN; and dicloxacillin, DICLOX), bacterial efflux pump inhibitors (piperine, PIP; carbonyl cyanide m-chlorophenyl hydrazone, CCCP), and bone morphogenetic protein (BMP-2) were evaluated individually and in combination to kill intracellular bacteria. We present direct evidence that after gentamicin killed extracellular planktonic bacteria and antibiotics had been stopped, seeding from the infected osteoblasts grew as biofilms. VAN was ineffective in treating the intracellular bacteria even at 10× MIC; however in presence of PIP or CCCP the intracellular S. aureus was significantly reduced. Bacterial efflux pump inhibitors (PIP and CCCP) were effective in enhancing permeability of antibiotics within the osteoblasts and facilitated killing of intracellular S. aureus. Confocal laser scanning microscopy (CLSM) showed increased uptake of propidium iodide within osteoblasts in presence of PIP and CCCP. BMP-2 had no effect on growth of S. aureus either alone or in combination with antibiotics. Combined application of antibiotics and natural agents could help in the treatment of osteoblast infected intracellular bacteria and biofilms associated with osteomyelitis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1086-1092, 2018.