Global Left Ventricular Myocardial Work Efficiency in Heart Failure Patients with Cardiac Amyloidosis: Pathophysiological Implications and Role in Differential Diagnosis.

INTRODUCTION: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy and a common cause of heart failure with preserved and mid-range ejection fraction (HFpEF and HFmrEF). Left ventricular (LV) systolic assessment is pivotal in differential diagnostic and prognostic stratification in CA. However, nondeformation and deformation-based parameters classically implied had many limitations. Myocardial work (MW) has been recently introduced for the evaluation of myocardial performance, in a load-independent fashion, in patients with cardiomyopathies. AIMS: This study aimed to evaluate MW parameters in LV performance assessment in CA and their possible role in differential diagnosis between AL and ATTR forms, compared with other echocardiographic parameters, also exploring the possible association between MW parameters and blood biomarkers. MATERIALS AND METHODS: The study population consisted of 25 patients with CA (10 with AL amyloidosis and 15 with wild-type ATTR [ATTRwt] form) and HFpEF or HFmrHF, enrolled between March 2018 and December 2019, undergoing a comprehensive clinical, biochemical, and imaging evaluation. Ten healthy individuals were studied as controls. ATTR patients had a noninvasive diagnosis of wtATTR-CA (positive 99mTc-hydroxy methylene-diphosphonate scintigraphy with a negative hematological screening), while AL patients underwent endomyocardial biopsy. All patients underwent standard transthoracic echocardiography. MW and related indices were estimated using a vendor-specific module. RESULTS: Compared to the ATTRwt group, patients in the AL group showed a more pronounced myocardial performance impairment assessed by Global Word Efficiency (GWE: 83.5% ± 6.3% vs. 88.2% ± 3.6%; P = 0.026). In multiple linear regression analysis, cardiac troponin I (Β = -0.55; P < 0.0001), global longitudinal strain (Β =0.35; P < 0.008), and regional relative strain ratio (Β = -0.30; P < 0.016) were significant predictors of GWE reduction in CA patients. At receiver operating characteristics curve analysis, among all other deformation-based and nondeformation-based echocardiographic parameters, GWE showed the highest area under the curve (AUC) (AUC 0.74; 95% CI: 0.55-0.96; P < 0.04). The optimal cutoff was determined by sensitivity/specificity analysis: a GWE < 86.5% identified patients with AL amyloidosis with a sensitivity and specificity, respectively, of 80.0% and 66.7%. CONCLUSIONS: The results of our pivotal study seem to highlight the importance of new deformation parameters to study myocardial performance in patients with CA, and to differentiate between AL CA and ATTR CA.

Hemodynamic assessment of Perceval sutureless bioprosthesis by dobutamine stress echocardiography.

OBJECTIVES: The aim of this study was to evaluate the hemodynamic performance of a sutureless bioprosthesis under high workload at mid-term follow-up. METHODS: Thirty-two patients who underwent isolated aortic valve replacement with a Perceval sutureless bioprosthesis with a minimum follow-up of 1 year were enrolled in this study. S size prosthesis was deployed in 10 patients (31.3%), M size in 9 (28.1%), L size in 8 (25%) and XL size in 5 (15.6%). Effective orifice area (EOA), EOA index (EOAi), and transvalvular gradients were assessed at rest and during dobutamine stress echocardiography (DSE) a median of 19.5 months after surgery. RESULTS: Dobutamine stress echocardiography (DSE) significantly increased heart rate, stroke volume, ejection fraction, and transvalvular gradients (peak gradient, 24.0 ± 7.6 vs 38.7 ± 13.6 mm Hg, P < .001; mean gradient, 12.6 ± 4.2 vs 19.8 ± 8.3, P < .001). When compared to baseline, estimated valve areas significantly increased at follow-up (EOA, 1.48 ± 0.46 vs 2.06 ± 0.67, P < .001; EOAi, 0.84 ± 0.26 vs 1.17 ± 0.37, P < .001). Mean percentage increase in EOAi was 40.3% ± 28.0%. S size prostheses had the highest increase in EOA1, but the difference was not significant (S 46.0% ± 27.5% vs M 45.4% ± 34.5% vs L 32.7% ± 26.4% vs XL 32.1% ± 20.5%, P = .66). Severe patient-prosthesis mismatch (EOAi ≤ 0.65 cm2 /m2 ) was present at rest in 8 patients (25%), but only in one patient (3.1%) during DSE. CONCLUSIONS: The Perceval sutureless bioprosthesis demonstrated good hemodynamics at rest and under high workload. The significant increase in EOAi during DSE suggests the potential advantages of Perceval sutureless bioprostheses in case of small aortic annulus or when patient-prosthesis mismatch is anticipated.

Personalizing oral anticoagulant treatment in patients with atrial fibrillation.

For decades, warfarin has remained the standard oral anticoagulation for stroke prevention in atrial fibrillation (AF). Three novel oral anticoagulants (NOACs) have been recently approved for stroke prevention in non-valvular AF: dabigatran, rivaroxaban and apixaban. Better pharmacological and clinical profiles make these newcomers a preferable alternative over warfarin. Current AF guidelines do not endorse NOACs over warfarin, or one NOAC over another. Indeed, choice of the anticoagulation regimen should be personalized based on the relative efficacy and safety of different agents across subgroups stratified by thrombotic and bleeding risk, as well as on other clinical factors, including anticoagulation control on warfarin, drug interactions, compliance and need for coagulation monitoring. This review appraises i) the randomized evidence on approved NOACs versus warfarin in AF across subgroups stratified by risk factors of stroke and bleeding and by the anticoagulation level reached on warfarin; and ii) clinical factors impacting on the anticoagulation regimen selection.

Platelet function profiles in the elderly: results of a pharmacodynamic study in patients on clopidogrel therapy and effects of switching to prasugrel 5 mg in patients with high platelet reactivity.

Studies specifically designed to assess clopidogrel response in the elderly as well as treatment alternatives to improve platelet inhibition in this high-risk population are lacking. This study aimed to define pharmacodynamic (PD) profiles, including high platelet reactivity (HPR) rates, among elderly patients on maintenance clopidogrel therapy and to assess the PD effects of prasugrel 5 mg/day in elderly with HPR. This was a prospective observational PD study enrolling consecutive ≥ 75-year-old patients on maintenance clopidogrel therapy (75 mg/day) who were tested for clopidogrel response by the VerifyNow P2Y12 assay and light transmittance aggregometry (LTA). HPR rates were estimated using multiple definitions. HPR patients identified by the VerifyNow P2Y12 assay [P2Y12 reaction unit (PRU) ≥ 230] were switched to prasugrel 5 mg/day, and platelet function testing was performed after 15 days of treatment. PD testing was completed in 100 patients. The HPR prevalence varied between 25% and 32%, depending on the definition used. A PRU ≥ 230 was observed in 25 patients; of these, 20 switched to prasugrel 5 mg/day. This resulted in significant reduction in PRU mean values (279.8 ± 45.1 vs. 171.7 ± 65.2, p=0.0002) with an absolute between-treatment difference of 108.1 (95% confidence intervals 75.2-140.9). Accordingly, switching to prasugrel 5 mg/day overcame HPR in most (80%) patients. Consistently, all LTA measures were significantly lower after prasugrel compared with clopidogrel. In conclusion, a considerable proportion of elderly patients exhibit HPR while on standard clopidogrel therapy. Switching to 5 mg/day prasugrel in elderly patients with HPR is associated with enhanced platelet inhibition and overcomes HPR in the majority of these patients.