Point of care with serial NT-proBNP measurement in patients with acute decompensated heart failure as a therapy-monitoring during hospitalization (POC-HF): Study protocol of a prospective, unblinded, randomized, controlled pilot trial

Despite important advances in diagnosis and medical therapy of heart failure (HF), disease monitoring and therapy guidance remains to be based on clinical signs and symptoms. NT-proBNP was repeatedly demonstrated to be a strong and independent predictor of morbidity and mortality in patients with HF. Only few – and conflicting – data are available on the efficacy of serial measurement of NT-proBNP as a tool for treatment monitoring in HF. These data are limited to the outpatient setting. Currently, no data are available on the effects of this approach in patients hospitalized for acute decompensated HF. The goal of this study is to explore whether the availability of serial NT-proBNP measurements may influence treatment decisions in patients with acute decompensated HF, and whether this leads to more rapid dose adjustments of prognostically beneficial medical therapies and earlier hospital discharge. In the intervention group, serial measurements of NT-proBNP every second business day are performed and made available to the treating physician, while no serial measurements are available in control group. HF therapy is left at the discretion of the treating physician. The primary endpoints are defined as the effects of monitoring NT-proBNP on medical HF therapy decisions, including type and dosing of medical therapies and the rapidity of adjustments, length of hospital stay, and evaluation of the changes in NT-proBNP values. Additional secondary endpoints include incidence of electrolyte imbalances and renal failure, changes in NYHA functional class, vital signs, body weight, quality of life, incidence of adverse events, transfer to Intensive Care Units, and mortality.

Cardiac myosin-binding protein C in the diagnosis and risk stratification of acute heart failure

AIMS

Cardiac myosin-binding protein C (cMyC) seems to be even more sensitive in the quantification of cardiomyocyte injury vs. high-sensitivity cardiac troponin, and may therefore have diagnostic and prognostic utility.

METHODS AND RESULTS

In a prospective multicentre diagnostic study, cMyC, high-sensitivity cardiac troponin T (hs-cTnT), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) plasma concentrations were measured in blinded fashion in patients presenting to the emergency department with acute dyspnoea. Two independent cardiologists centrally adjudicated the final diagnosis. Diagnostic accuracy for acute heart failure (AHF) was quantified by the area under the receiver operating characteristic curve (AUC). All-cause mortality within 360 days was the prognostic endpoint. Among 1083 patients eligible for diagnostic analysis, 51% had AHF. cMyC concentrations at presentation were higher among AHF patients vs. patients with other final diagnoses [72 (interquartile range, IQR 39-156) vs. 22 ng/L (IQR 12-42), P < 0.001)]. cMyC's AUC was high [0.81, 95% confidence interval (CI) 0.78-0.83], higher than hs-cTnT's (0.79, 95% CI 0.76-0.82, P = 0.081) and lower than NT-proBNP's (0.91, 95% CI 0.89-0.93, P < 0.001). Among 794 AHF patients eligible for prognostic analysis, 28% died within 360 days; cMyC plasma concentrations above the median indicated increased risk of death (hazard ratio 2.19, 95% CI 1.66-2.89; P < 0.001). cMyC's prognostic accuracy was comparable with NT-proBNP's and hs-cTnT's. cMyC did not independently predict all-cause mortality when used in validated multivariable regression models. In novel multivariable regression models including medication, age, left ventricular ejection fraction, and discharge creatinine, cMyC remained an independent predictor of death and had no interactions with medical therapies at discharge.

CONCLUSION

Cardiac myosin-binding protein C may aid physicians in the rapid triage of patients with suspected AHF.

A framework for continuous target tracking during MR-guided high intensity focused ultrasound thermal ablations in the abdomen

Background

During lengthy magnetic resonance-guided high intensity focused ultrasound (MRg-HIFU) thermal ablations in abdominal organs, the therapeutic work-flow is frequently hampered by various types of physiological motion occurring at different time-scales. If left un-addressed this can lead to an incomplete therapy and/or to tissue damage of organs-at-risk. While previous studies focus on correction schemes for displacements occurring at a particular time-scale within the work-flow of an MRg-HIFU therapy, in the current work we propose a motion correction strategy encompassing the entire work-flow.

Methods

The proposed motion compensation framework consists of several linked components, each being adapted to motion occurring at a particular time-scale. While respiration was addressed through a fast correction scheme, long term organ drifts were compensated using a strategy operating on time-scales of several minutes. The framework relies on a periodic examination of the treated area via MR scans which are then registered to a reference scan acquired at the beginning of the therapy. The resulting displacements were used for both on-the-fly re-optimization of the interventional plan and to ensure the spatial fidelity between the different steps of the therapeutic work-flow. The approach was validated in three complementary studies: an experiment conducted on a phantom undergoing a known motion pattern, a study performed on the abdomen of 10 healthy volunteers and during 3 in-vivo MRg-HIFU ablations on porcine liver.

Results

Results have shown that, during lengthy MRg-HIFU thermal therapies, the human liver and kidney can manifest displacements that exceed acceptable therapeutic margins. Also, it was demonstrated that the proposed framework is capable of providing motion estimates with sub-voxel precision and accuracy. Finally, the 3 successful animal studies demonstrate the compatibility of the proposed approach with the work-flow of an MRg-HIFU intervention under clinical conditions.

Conclusions

In the current study we proposed an image-based motion compensation framework dedicated to MRg-HIFU thermal ablations in the abdomen, providing the possibility to re-optimize the therapy plan on-the-fly with the patient on the interventional table. Moreover, we have demonstrated that even under clinical conditions, the proposed approach is fully capable of continuously ensuring the spatial fidelity between the different phases of the therapeutic work-flow.