Right vs. left ventricular longitudinal strain for mortality prediction after transcatheter aortic valve implantation.

Introduction: This study aims at exploring biventricular remodelling and its implications for outcome in a representative patient cohort with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). Methods and results: Pre-interventional echocardiographic examinations of 100 patients with severe AS undergoing TAVI were assessed by speckle tracking echocardiography of both ventricles. Association with mortality was determined for right ventricular global longitudinal strain (RVGLS), RV free wall strain (RVFWS) and left ventricular global longitudinal strain (LVGLS). During a median follow-up of 1,367 [959-2,123] days, 33 patients (33%) died. RVGLS was lower in non-survivors [-13.9% (-16.4 to -12.9)] than survivors [-17.1% (-20.2 to -15.2); P = 0.001]. In contrast, LVGLS as well as the conventional parameters LV ejection fraction (LVEF) and RV fractional area change (RVFAC) did not differ (P = ns). Kaplan-Meier analyses indicated a reduced survival probability when RVGLS was below the -14.6% cutpoint (P < 0.001). Lower RVGLS was associated with higher mortality [HR 1.13 (95% CI 1.04-1.23); P = 0.003] independent of LVGLS, LVEF, RVFAC, and EuroSCORE II. Addition of RVGLS clearly improved the fitness of bivariable and multivariable models including LVGLS, LVEF, RVFAC, and EuroSCORE II with potential incremental value for mortality prediction. In contrast, LVGLS, LVEF, and RVFAC were not associated with mortality. Discussion: In patients with severe AS undergoing TAVI, RVGLS but not LVGLS was reduced in non-survivors compared to survivors, differentiated non-survivors from survivors, was independently associated with mortality, and exhibited potential incremental value for outcome prediction. RVGLS appears to be more suitable than LVGLS for risk stratification in AS and timely valve replacement.

The incremental value of the contribution of a biostatistician to the reporting quality in health research-A retrospective, single center, observational cohort study.

BACKGROUND: The reporting quality in medical research has recently been critically discussed. While reporting guidelines intend to maximize the value from funded research, and initiatives such as the EQUATOR network have been introduced to advance high quality reporting, the uptake of the guidelines by researchers could be improved. The aim of this study was to assess the contribution of a biostatistician to the reporting and methodological quality of health research, and to identify methodological knowledge gaps. METHODS: In a retrospective, single center, observational cohort study, two groups of publications were compared. The group of exposed publications had an academic biostatistician on the author list, whereas the group of non-exposed publications did not include a biostatistician of the evaluated group. Rating of reporting quality was done in blinded fashion and in duplicate. The primary outcome was a sum score based on six dimensions, ranging between 0 (worst) and 11 (best). The study protocol was reviewed and approved as a registered report. RESULTS: There were 131 publications in the exposed group published between 2017 and 2018. Of these, 95 were either RCTs, observational, or prediction / prognostic studies. Corresponding matches in the group of non-exposed publications were identified in a reproducible manner. Comparison of reporting quality overall revealed a 1.60 (95%CI from 0.92 to 2.28, p <0.0001) units higher reporting quality for exposed publications. A subgroup analysis within study types showed higher reporting quality across all three study types. CONCLUSION: Our study is the first to report an association of a higher reporting quality and methodological strength in health research publications with a biostatistician on the author list. The higher reporting quality persisted through subgroups of study types and dimensions. Methodological knowledge gaps were identified for prediction / prognostic studies, and for reporting on statistical methods in general and missing values, specifically.

A three-year longitudinal study of retinal function and structure in patients with multiple sclerosis.

BACKGROUND: Researchers have in recent years begun to investigate ophthalmological manifestations of multiple sclerosis (MS) other than optic neuritis (ON), and it is now clear that changes to retinal function (measured using the electroretinogram, ERG) and structure (measured using optical coherence tomography, OCT) are found in MS patients irrespective of prior ON episodes. ERG results are consistent with dysfunctional bipolar cells, as in other autoimmune diseases. To date, studies have presented only cross-sectional data regarding ERG and OCT. We, therefore, studied the longitudinal course of ERG and OCT in patients with MS, as well as the effect of disability changes and non-ON clinical relapses on these functional and structural measures. METHODS: MS patients (n = 23) participating in an ongoing longitudinal observational study were invited to take part in a 3-year ophthalmological substudy. ERG and OCT were performed, and measures of MS-related disability and relapse history were obtained. Study visits were repeated annually. ERG peak times, rod b-wave amplitude, mixed rod/cone and cone b-/a-wave amplitude ratios, thickness of the peripapillary retinal nerve fibre layer, and volumes of the segmented retinal layers/complexes were analysed. Using generalised estimating equation models adjusted for age, ON, and MS treatment status, we assessed changes to ERG and OCT over the study duration, the effect of changes in disability and recent non-ON MS relapses on ERG and OCT, and the effect of selected OCT parameters on corresponding ERG parameters. RESULTS: At the group level, small fluctuations of several ERG peak times were recorded, with OCT values remaining stable. Increased disability between visits was associated with significant prolongation of mixed rod-cone ERG b-wave peak times. No evidence of associations between OCT and ERG parameters was observed. CONCLUSIONS: Retinal bipolar cell function may be affected by changes in disability in patients with MS; however, recent non-ON MS clinical relapses appear not to affect ERG or OCT results. As ERG changes in MS patients over 3 years are likely to be small and of uncertain clinical relevance, longitudinal studies of retinal function in MS should be planned over an extended period.

Is reporting quality in medical publications associated with biostatisticians as co-authors? A registered report protocol.

BACKGROUND: Quality in medical research has recently been criticized for being low, especially in observational research. Methodology is increasingly difficult, but collaboration between clinical researchers and biostatisticians may improve research and reporting quality. The aim of this study is to quantify the value of a biostatistician in the team of authors. METHODS: Single-center, retrospective observational study following the STROBE reporting guidelines. We will systematically review all medical publications with biostatisticians from our center as co-authors or authors and review corresponding papers without biostatisticians from our center during the same time range. We will compare aspects of reporting quality, overall and for the three study types observational, randomized trial, and prognostic separately. DISCUSSION: We anticipate that the results of the study will raise awareness of the importance of high methodological quality, as well as appropriate reporting quality in clinical research. CONCLUSION: Our study will have a direct impact on our center by making each of us more aware of the reporting guidelines for various research designs. This in turn will enhance reporting quality in future research with our involvement. Our study will also raise awareness of the important role that biostatisticians play in the design and analysis of health research projects.

Extensive Histological Sampling following Focal Therapy of Clinically Significant Prostate Cancer with High Intensity Focused Ultrasound.

PURPOSE: Clinically significant, localized prostate cancer is currently treated with whole gland therapy. This approach is effective but associated with genitourinary and rectal side effects. Focal therapy of prostate cancer has been proposed as an alternative. The aim of this study was to determine the oncologic and functional outcomes of focal high intensity focused ultrasound therapy of prostate cancer. MATERIALS AND METHODS: In this single center, prospective study 75 men were treated between April 2014 and April 2018. Multiparametric magnetic resonance imaging and transperineal template saturation prostate biopsy were performed to localize prostate cancer, followed by focal ablation with high intensity focused ultrasound. The study primary end point was the detection of clinically significant prostate cancer, defined as Gleason score 7 or greater, at 6-month followup transperineal template saturation prostate biopsy. Genitourinary side effects were of secondary interest. RESULTS: Median patient age was 67 years (IQR 60-71) and median prostate specific antigen was 5.87 ng/ml (IQR 4.65-7.44). There were 5 low risk (6.7%) and 70 intermediate risk (93.3%) cancers. Clinically significant prostate cancer was detected in 41% of the men (95% CI 30.3-53.0) who underwent biopsy at 6 months and the median number of sampled cores was 44 (IQR 36-44). Prostate specific antigen (OR 1.17, IQR 0.49-2.85, p=0.71) and multiparametric magnetic resonance imaging (14.3% sensitivity, IQR 6.7-31.5) performed poorly to predict positive biopsies. Pad-free continence and erection sufficient for penetration were preserved in 63 of 64 (98.4%) and 31 of 45 patients (68.9%), respectively. CONCLUSIONS: Focal therapy with high intensity focused ultrasound leads to a low rate of genitourinary side effects. Followup biopsy of treated and untreated prostates remains the only modality to adequately select men in need of early salvage treatment.