Multireader image quality evaluation of dynamic myocardial computed tomography perfusion imaging with a novel four-dimensional noise reduction filter

BACKGROUND

Dynamic myocardial computed tomography perfusion (CTP) is a novel technique able to depict cardiac ischemia.

PURPOSE

To evaluate the impact of a four-dimensional noise reduction filter (similarity filter [4D-SF]) on image quality in dynamic CTP imaging, allowing for substantial radiation dose reduction.

MATERIAL AND METHODS

Dynamic CTP datasets of 30 patients (16 women) with suspected coronary artery disease, acquired with a 320-slice CT system, were retrieved, reconstructed with the deep learning-based algorithm of the system (DLR), and filtered with the 4D-SF. For each case, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in six regions of interest (33-38mm²) were calculated before and after filtering, in four-chamber and short-axis views, and t-tested. Furthermore, six radiologists of different expertise evaluated subjective image preference by answering five visual grading analysis-type questions (regarding acceptable level of noise, absence of artifacts, natural appearance, cardiac contour sharpness, diagnostic acceptability) using a 5-point scale. The results were analyzed using visual grade characteristics (VGC) and intraclass correlation coefficient (ICC).

RESULTS

Mean SNR in four-chamber view (unfiltered vs. filtered) were: septum=4.1 ± 2.1 versus 7.6 ± 5.6; lateral wall=4.5 ± 2.0 versus 8.0 ± 4.9; CNRseptum=16.6 ± 8.9 versus 31.7 ± 28; lateral wall=16.2 ± 8.9 versus 31.3 ± 28.9. Similar results were obtained in short-axis view. The perceived filtered image quality indicated decreased noise (VGC_AUC=0.96) and artifacts (0.65), improved natural appearance (0.59), cardiac contour sharpness (0.74), and diagnostic acceptability (0.78). The inter-observer variability was excellent (ICC=0.79). All results were statistically significant (P < 0.05).

CONCLUSION

Similarity filtering after DLR improves image quality, possibly enabling dose reduction in dynamic CTP imaging in patient with suspected chronic coronary syndrome.

Validation of the ELAN-HF Score and self-care behaviour on the nurse-led heart failure clinic after admission for heart failure

AIM

To validate the predictive value of the European coLlaboration on Acute decompeNsated Heart Failure (ELAN-HF) score, and to assess the effect of self-care behaviour on readmission and mortality in patients after admission with acute decompensated heart failure (ADHF).

DESIGN

Quantitative, prospective, single centre, cohort study.

METHODS

N-Terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured on admission and discharge, and were used together with clinical and laboratory parameters to calculate the ELAN-HF score. Patients were stratified into four risk groups (low, intermediate, high, very high) according to their ELAN-HF score. The performance of the ELAN-HF score was evaluated and compared to the original study. Self-care behaviour was assessed by the European Heart Failure Self-care Behaviour Scale (EHFScBS-9). Survival analysis was used to estimate the association between both scores and re-admission for HF and/or all-cause mortality within 180 days.

RESULTS

88 patients were included. The median age of the study population was 75 years (IQR 69-83), 43% was female. NYHA III/IV functional class was present at discharge in 68 patients (85%) and 27 patients (34%) had a left ventricular ejection fraction < 40%. Complete data and 180 day follow up was available for 80 patients. 55% reached the endpoint of readmission and/or all-cause mortality. There was a significant association between the ELAN-HF score and re-admission and/or mortality < 180 days (HR = 1.25, 95% CI 1.08-1.45, p = 0.003). The median EHFScBS-9 score was 68.1 (IQR 58.3 - 77.8). There was no significant association between the EHFScBS-9 score and readmission and/or mortality < 180 days (HR = 1.01, 95% CI 0.99-1.03, p = 0.174).

CONCLUSION

This study confirms the validity and therefore the potential of the ELAN-HF score to triage patients with ADHF before discharge. Using this score may optimize the follow-up treatment on the nurse-led heart failure clinic in order to decrease readmission and mortality. Self-care behaviour was non-significantly associated with readmission and/or mortality in our study population.

TRIAL REGISTRATION

This study has been registered with the ethics committee MEC-U (Nieuwegein, The Netherlands), registration nr: V.160999/W18.208/HG/mk.

External Validation of the ELAN-HF Score, Predicting 6-Month All-Cause Mortality in Patients Hospitalized for Acute Decompensated Heart Failure

Background

Our aim was to calibrate and externally revalidate the ELAN‐HF (European Collaboration on Acute Decompensated Heart Failure) score, to confirm and improve on a previous external validation of the risk score.

Methods and Results

The ELAN‐HF score predicts 6‐month all‐cause mortality in patients hospitalized for acute decompensated heart failure using absolute and percentage change of NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) levels in addition to clinical variables. For the external validation, we used the PRIMA II (Can NT‐proBNP–Guided Therapy During Hospital Admission for Acute Decompensated Heart Failure Reduce Mortality and Readmissions?) trial. For both data sets, observed versus predicted mortality was compared for the 4 risk categories; and the mean predicted mortality was plotted against the observed mortality with calculation of a correlation coefficient and SEE. The model discriminant ability was determined by comparing the C‐statistics for both data sets. The predicted versus actual 6‐month mortality values in the derivation cohort were 3.7% versus 3.6% for the low‐risk category, 9.4% versus 9.2% for the intermediate‐risk category, 24.2% versus 23.5% for the high‐risk category, and 54.2% versus 51.1% for the very‐high‐risk category. The correlation between predicted and observed mortality by deciles was 0.92, with an SEE of ±4%. In the validation cohort, predicted versus actual 6‐month mortality values were 3.0% versus 2.2% for the low‐risk category, 9.4% versus 8.2% for the intermediate‐risk category, 25.0% versus 22.9% for the high‐risk category, and 56.8% versus 53.6% for the very‐high‐risk category. The correlation between predicted and actual mortality by quintiles was 0.99, with an SEE of ±2%. There was no significant difference in C‐statistic between the derivation cohort (0.78; 95% CI, 0.74–0.82) and the validation cohort (0.77; 95% CI, 0.69–0.84; P=0.693).

Conclusions

Our study confirms that the ELAN‐HF score predicts accurately 6‐month mortality in patients hospitalized for acute decompensated heart failure with the use of easily obtained characteristics.

Prognosis and NT-proBNP in heart failure patients with preserved versus reduced ejection fraction

BACKGROUND

We assessed the prognostic significance of absolute and percentage change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in patients hospitalised for acute decompensated heart failure with preservedejection fraction (HFpEF) versus heart failure with reduced ejection fraction (HFrEF).

METHODS

Patients with left ventricular ejection fraction ≥50% were categorised as HFpEF (n=283), while those with <40% as were categorised as HFrEF (n=776). Prognostic values of absolute and percentage change in NT-proBNP levels for 6 months all-cause mortality after discharge were assessed separately in patients with HFpEF and HFrEF by multivariable adjusted Cox regression analysis. Comorbidities were compared between heart failure groups.

RESULTS

Discharge NT-proBNP levels predicted outcome similarly in HFpEF and HFrEF: for any 2.7-factor increase in NT-proBNP levels, the HR for mortality was 2.14 for HFpEF (95% CI 1.48 to 3.09) and 1.96 for HFrEF (95% CI 1.60 to 2.40). Mortality prediction was equally possible for NT-proBNP reduction of ≤30% (HR 4.60, 95% CI 1.47 to 14.40 and HR 3.36, 95% CI 1.93 to 5.85 for HFpEF and HFrEF, respectively) and for >30%-60% (HR 3.28, 95% CI 1.07 to 10.12 and HR 1.79, 95% CI 0.99 to 3.26, respectively), compared with mortality in the reference groups of >60% reductions in NT-proBNP levels. Prognostically relevant comorbidities were more often present in patients with HFpEF than patients with HFrEF in low (≤3000 pg/mL) but not in high (>3000 pg/mL) NT-proBNP discharge categories.

CONCLUSIONS

Our study highlights-after demonstrating that NT-proBNP levels confer the same relative risk information in HFpEF as in HFrEF-the possibility that comorbidities contribute relatively more to prognosis in patients with HFpEF with lower NT-proBNP levels than in patients with HFrEF.

Targeting N-Terminal Pro-Brain Natriuretic Peptide in Older Versus Younger Acute Decompensated Heart Failure Patients

OBJECTIVES

The aim of this study was to analyze the prognostic value and attainability of N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in young and elderly acute decompensated heart failure (ADHF) patients.

BACKGROUND

Less-effective NT-proBNP-guided therapy in chronic heart failure (HF) has been reported in elderly patients. Whether this can be attributed to differences in prognostic value of NT-proBNP or to differences in attaining a prognostic value is unclear. The authors studied this question in ADHF patients.

METHODS

Our study population comprised 7 ADHF cohorts. We defined absolute (<1,500 ng/l, <3,000 ng/l, <5,000 ng/l, and <15,000 ng/l) and relative NT-proBNP discharge cut-off levels (>30%, >50%, and >70%). Six-month all-cause mortality after discharge was studied for each level in Cox regression analyses, and compared between elderly (age >75 years) and young patients (age ≤75 years). Thereafter, we compared percentages of elderly and young patients attaining NT-proBNP levels (= attainability).

RESULTS

A total of 1,235 patients (59% male, 45% >75 years of age) was studied. Admission levels of NT-proBNP were significantly higher in elderly versus younger patients. The prognostic value of absolute and relative NT-proBNP levels was similar in elderly and young patients. Attainability was significantly lower in elderly patients for all absolute levels and a >50% relative reduction, but not for >30% and >70%. For absolute levels, attainability differences between age groups were decreased to a large extent after correction for admission NT-proBNP and anemia at discharge. For relative levels, attainability differences disappeared after correction for HF etiology and anemia at discharge.

CONCLUSIONS

In young and elderly ADHF patients, it is not the prognostic value of absolute and relative NT-proBNP levels that is different, but the attainability of these levels that is lower in the elderly. This can largely be attributed to factors other than age.

Serum potassium decline during hospitalization for acute decompensated heart failure is a predictor of 6-month mortality, independent of N-terminal pro-B-type natriuretic peptide levels: An individual patient data analysis

BACKGROUND

Limited data exist for the role of serum potassium changes during hospitalization for acute decompensated heart failure (ADHF). The present study investigated the long-term prognostic value of potassium changes during hospitalization in patients admitted for ADHF.

METHODS

Our study is a pooled individual patient data analysis assembled from 3 prospective cohorts comprising 754 patients hospitalized for ADHF. The endpoint was all-cause mortality within 180 days after discharge. Serum potassium levels and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured at admission and at discharge.

RESULTS

A percentage decrease >15% in serum potassium levels occurred in 96 (13%) patients, and an absolute decrease of >0.7 mmol/L in serum potassium levels occurred in 85 (12%) patients; and both were predictors of poor outcome independent of admission or discharge serum potassium. After the addition of other strong predictors of mortality-a 30% change in NT-proBNP during hospitalization, discharge levels of NT-proBNP, renal markers, and other relevant clinical variables-the multivariate hazard ratio of serum potassium percentage reduction of >15% remained an independent predictor of 180-day mortality (hazard ratio 2.06, 95% CI 1.14-3.73).

CONCLUSIONS

A percentage serum potassium decline of >15% is an independent predictor of 180-day all-cause mortality on top of baseline potassium levels, NT-proBNP levels, renal variables, and other relevant clinical variables. This suggest that patients hospitalized for ADHF with a decline of >15% in serum potassium levels are at risk and thus monitoring and regulating of serum potassium level during hospitalization are needed in these patients.

A novel discharge risk model for patients hospitalised for acute decompensated heart failure incorporating N-terminal pro-B-type natriuretic peptide levels: a European coLlaboration on Acute decompeNsated Heart Failure: ELAN-HF Score

BACKGROUND

Models to stratify risk for patients hospitalised for acute decompensated heart failure (ADHF) do not include the change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels during hospitalisation.

OBJECTIVE

The aim of our study was to develop a simple yet robust discharge prognostication score including NT-proBNP for this notorious high-risk population.

DESIGN

Individual patient data meta-analyses of prospective cohort studies.

SETTING

Seven prospective cohorts with in total 1301 patients.

PATIENTS

Our study population was assembled from the seven studies by selecting those patients admitted because of clinically validated ADHF, discharged alive, and NT-proBNP measurements available at admission and at discharge.

MAIN OUTCOME MEASURES

The endpoints studied were all-cause mortality and a composite of all-cause mortality and/or first readmission for cardiovascular reason within 180 days after discharge.

RESULTS

The model that incorporated NT-proBNP levels at discharge as well as the changes in NT-proBNP during hospitalisation in addition to age ≥75 years, peripheral oedema, systolic blood pressure ≤115 mm Hg, hyponatremia at admission, serum urea of ≥15 mmol/L and New York Heart Association (NYHA) class at discharge, yielded the best C-statistic (area under the curve, 0.78, 95% CI 0.74 to 0.82). The addition of NT-proBNP to a reference model significantly improved prediction of mortality as shown by the net reclassification improvement (62%, p<0.001). A simplified model was obtained from the final Cox regression model by assigning weights to individual risk markers proportional to their relative risks. The risk score we designed identified four clinically significant subgroups. The pattern of increasing event rates with increasing score was confirmed in the validation group (BOT-AcuteHF, n=325, p<0.001).

CONCLUSIONS

In patients hospitalised for ADHF, the addition of the discharge NT-proBNP values as well as the change in NT-proBNP to known risk markers, generates a relatively simple yet robust discharge risk score that importantly improves the prediction of adverse events.

Evolution of cerebral perfusion techniques in type a aortic dissection surgery: a single center experience

BACKGROUND

The purpose of this study was to investigate the effect of using antegrade selective cerebral perfusion (ASCP) with moderate hypothermia on hospital mortality after surgery for acute type A aortic dissection (AAAD).

METHODS

Between January 1998 and December 2008, 142 consecutive patients were operated on for AAAD. Patients were divided into two subgroups: the cohort of patients operated on from January 1998 until December 2003 (without ASCP) (P1998-2003, n=64) and the cohort operated on from January 2004 until December 2008 (with ASCP)(P2004-2008, n=78).

RESULTS

The difference in hospital mortality was statistically significant (P1998-2003: 42.2%; P2004-2008: 14.1%, p<0.0005). Survival rates were 51.6±6.2% vs. 75.1±5.5% and 45.9±6.2% vs. 69.7±7.3% for one and four years, respectively (p=0.001). Multivariate logistic regression analysis revealed that ASCP was the only independent protective factor of hospital mortality (p=0.047).

CONCLUSION

In patients operated on for AAAD, antegrade selective cerebral perfusion with moderate hypothermia is a significant factor in decreasing hospital mortality.

Transmission of circulating schistosomal antigens from infected mothers to their newborns

Two previous reports have appeared in the literature regarding tansplacental transfer of Schistosoma mansoni antigens which raised the question of its reality. In a previous study the senior author, and others (1992 & 1997) detected circulating antigens of S. mansoni and S. haematobium in infected patients, using monoclonal antibodies 128C3, with a very high sensitivity using ELISA. This work tried to answer the question of antigen transfer possibility using a high sensitive assay in 50 mothers and their newborns at birth and 1, 3, and 6 months after delivery. The assay used in the present work could detect circulating S. mansoni antigens in 45 infected mothers (90%) with active S. mansoni infection. A significant direct increase in mean antigen levels was found with the intensity of infection evaluated by egg counting (p < 0.01). The clinical stage of the diseased mothers was apparently unrelated to the ELISA test values as no significant relations were observed. Positive antigen levels were detected in 33 newborns (66%) of the 45 positive antigen mothers, then the percentage positivity was directly decreased with the advancement of age as only 5 infants (10%) had positive antigen levels compared to 0% at 6 months of age. A positive correlation between newborn serum antigen concentration and concentration of antigen in sera of their mothers was obtained. This work answers some of the questions concerning the ability of the used monoclonal to detect antigens in newborns and the possibility of antigen transfer through the placenta alone or incorporated in immune complexes forms. This work clarifies the time of antigen disappearance from the circulation.