2 Minute Medicine Rewind January 12, 2015 – January 19, 2015

In this section, we highlight the key high-impact studies, updates, and analyses published in medicine during the past week.

Factor XI Antisense Oligonucleotide for Prevention of Venous Thrombosis

There is data to suggest that targeting factor XI might attenuate thrombosis without affecting hemostasis, making this an effective therapeutic target particularly for post-op patients. FXI-ASO is a second generation antisense oligonucleotide that reduces factor XI levels, and this open-label randomized trial attempted to determine the clinical efficacy of FXI-ASO. Three hundred unilateral total knee arthroplasty patients were assigned to one of the three groups: with the first group receiving 200 mg FXI-ASO, the second receiving 300 mg FXI-ASO, and the control receiving 40 mg enoxaparin daily. The incidence of venous thromboembolism and clinically relevant bleeding episodes were assessed. Twenty seven percent of patients who received 200 mg of FXI-ASO, 4% of the patients who received 300 mg of FXI-ASO, and 30% of patients who received enoxaparin experienced venous thromboembolism. Three percent of patients in the 200 mg of FXI-ASO group, 3% of patients in the 300 mg of FXI-ASO, and 8% of patients in enoxaparin group experienced major or clinically relevant non-major bleeding. Overall, the treatment with 200 mg of FXI-ASO proved non-inferior and the treatment with 300 mg of FXI-ASO was superior to the standard of care with enoxaparin (p<0.001).

Sodium Zirconium Cyclosilicate in Hyperkalemia

This study investigated whether a novel selective cation exchanger, sodium zirconium cyclosilicate (ZS-9), might be a useful treatment for hyperkalemia, an important complication associated with increased mortality in chronic kidney disease, heart failure, or diabetes. In this phase 3 double-blinded study, 753 patients with hyperkalemia were assigned to receive either ZS-9 at doses of 1.25 g, 2.5 g, 5 g, or 10 g or placebo three times per day for 48 hours. Patients whose K normalized at 48 hours were then assigned to receive either additional ZS-9 or placebo once daily for days 3 to 14. The mean serum levels of potassium at 48 hours for groups receiving 1.25, 2.5 g, 5 g, 10 g of ZS-9 or placebo were the following: 5.1, 4.9, 4.8, 4.6, 5.1 mmol/liter, respectively. These represented mean reductions from the baseline potassium of 5.3 mmol/liter of 0.3, 0.5 (p<0.001), 0.5 (p<0.001), 0.7 (p<0.001), and 0.3 mmol/liter, for the respective groups. In patients who received 5 g and 10 g of ZS-9, the potassium levels were maintained at 4.7 and 4.5 mmol/liter, respectively during days 3-14 (as compared to 5.0 mmol/liter in the placebo group, p<0.01). Rates of adverse events were similar in the ZS-9 and placebo groups during the initial 48 hours and the 3-14 day period, with diarrhea the most common side effect. Thus, this study showed that ZS-9 is an important treatment option to consider in hyperkalemia.

Differences in Breast Cancer Stage at Diagnosis and Cancer-Specific Survival by Race and Ethnicity in the United States

This study aimed to determine whether patient’s race/ethnicity might have an impact on the proportion of breast cancers identified at stage I and the survival rates following the stage I diagnosis. 373,563 women (71.9% non-Hispanic white, 9.4% Hispanic white, 10.4% black, 6.7% Asian, and 1.6% other ethnicities) diagnosed with invasive breast cancer from 2004-2011 were included in the study, with the mean follow up data of 40.6 months. Women within each of the racial/ethnic groups were then evaluated for the biological aggressiveness of tumor based on the triple negative status, lymph node metastases, and distant metastases. The odds ratio for being diagnosed at stage I versus a later stage as well as the hazard ratio of death from stage I breast cancer by racial/ethic groups were then evaluated. Japanese women were more likely to be diagnosed at stage I compared to non-Hispanic white women (OR 1.23, 95% CI 1.15-1.31, P<0.001). Black women were less likely to be diagnosed at stage I compared to non-Hispanic white women (OR 0.65, 95% CI 0.64-0.67, p<0.001). Risk of death from stage I breast cancer at 7 years was higher in black women compared to non-Hispanic white women (HR 1.57, 95% CI 1.40-1.75, p<0.001) and lower in South Asian women compared to non-Hispanic white women (HR 0.48, 95% CI 0.20-1.15, p = 0.1). Thus, this study concluded that race/ethnicity impacts the likelihood of diagnosis at an early stage as well as the survival after stage I breast cancer diagnosis for US women with invasive breast cancers, with much of the difference accounted for by differences in triple negative behavior of the tumors, lymph node metastases, and distant metastases.

A Randomized Comparative Effectiveness Trial of Novel Endoscopic Techniques and Approaches for Barrett’s Esophagus Screening in the Community

The incidence of the esophageal cancer has risen over the past years, and its survival rates remain low. Although screening for Barrett’s esophagus is recommended in high risk populations and it is known that Barrett’s esophagus can progress to esophageal adenocarcinoma, Barrett’s esophagus remains undiagnosed. Thus, the new ways of conducting esophageal assessments might be needed in the community. This prospective, randomized trial compared the clinical effectiveness between two modes of screening for Barrett’s esophagus in a population based cohort, including the unsedated transnasal endoscopy and sedated esophagogastroduodenoscopy. 209 patients were randomized to complete the screening with either the mobile research van transnasal endoscopy, the mobile research van esophagogastroduodenoscopy, or the outpatient endoscopy suite transnasal endoscopy. Retention rates for participation in the study were higher in the transnasal endoscopy patients at both mobile and outpatient settings compared to the esophagogastroduodenoscopy, but the differences were not statistically significant. Complete evaluation of the esophagus was comparable in the three groups. Evaluation time with transnasal endoscopy was considerably shorter compared to esophagogastroduodenoscopy. Mean recovery times were longer for esophagogastroduodenoscopy compared to mobile or outpatient transnasal endoscopy, with the time difference between esophagogastroduodenoscopy and mobile transnasal endoscopy of 51.8 minutes (p < 0.001) and the time difference between esophagogastroduodenoscopy and outpatient transnasal endoscopy of 48.8 minutes (p < 0.001). Thus, this study concluded that mobile van and clinic transnasal endoscopies have comparable effectiveness compared to esophagogastroduodenoscopy and may provide an effective alternative strategy for Barrett’s esophagus screening.

Computer-Generated vs. Physician-Documented History of Present Illness (HPI): Results of a Blinded Comparison

This study was designed to compare histories of present illness (HPIs) as generated by the physicians during an in-person visit and a computer generated algorithm called the Automated Evaluation of Gastrointestinal Symptoms (AEGIS). Seventy five patients with active GI symptoms were recruited for the study across the GI clinics, with each patient first attending an office visit, resulting in a physician documented HPI, and then completing the AEGIS, resulting in a computer generated HPI. Forty eight blinded physicians then assessed the HPI quality based on six domains using a 5 point scale: overall impression, thoroughness, usefulness, organization, succinctness, and comprehensibility. The mean overall impression score for computer generated HPIs was higher compared to physician documented HPIs (3.68 vs 2.80, p<0.001). Computer generated HPIs also received higher thoroughness scores (3.70 vs 2.73, p<0.001), higher usefulness score (3.82 vs 3.04, p<0.001), higher organization scores (3.66 vs 2.80, p<0.001), higher succinctness scores (3.55 vs 3.17, p<0.001), and higher comprehensibility scores (3.66 vs 2.97, p<0.001). Thus, in this GI-based practice study, the computer generated HPIs were overall judged to be superior as compared to the physician documented HPIs based on the proposed six domains of evaluation.

Image: PD

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