Stem cells for knee osteoarthritis
A randomised control trial in Nature Medicine hypothesised that cell therapies would be more effective than corticosteroid injections for reducing pain from knee osteoarthritis at one year. The researchers looked at three different sources of stem cell injection—from the bone marrow, adipose tissue, and umbilical cord—to see which would be more effective. A total of 480 people aged between 40 and 70 years with knee osteoarthritis were randomised and had their treatment concealed by means of sham cell harvesting procedures. Pain scores were lower after a year in each of the four arms of the study, but none of the cell therapy treatments were any more effective than corticosteroids.
Nat Med doi:10.1038/s41591-023-02632-w
Gender gap in clinical trials
For those embarking on a career in clinical research, being a principal investigator (PI) of a trial is a big deal. Looking at the gender of PIs is therefore a useful way to monitor the gender gap in academia.
A cross-sectional study reviewed trials registered on clinicaltrials.gov between 2005 and 2023 and determined the gender of the PI named on each study using the software genderize.io. Tell it any name, and it will give you a predicted gender for that name with a probability (have a go by adding a name to the following url: https://api.genderize.io/?name=). From over 290 000 PIs, the study found 32.4% were women. Gender gaps varied according to clinical specialty: cardiology (20.3%) and hepatology (21.4%) had the lowest rates of women PIs, while rheumatology (49.2%) had the highest.
The study also found that women were more likely to be PIs in observational rather than interventional studies, in phase I rather than phase III trials, and in the US and Europe compared with Asia—but in each of these women were far outnumbered by men.
JAMA Intern Med doi:10.1001/jamainternmed.2023.5104
Pulsed field ablation for atrial fibrillation
Success rates of catheter ablation for atrial fibrillation aren’t as high as one would hope: only 43% of those with persistent and longstanding atrial fibrillation manage to remain off anti-arrhythmic drugs a year after the procedure. Pulsed field ablation uses high amplitude electrical pulses to ablate myocardium without any significant heating (in contrast to catheter ablation). The hope for this newer technology was it could be more effective, while also avoiding the risk of atrio-oesophageal fistula.
The ADVENT trial, a randomised, single-blind, non-inferiority trial, compared pulsed field ablation with catheter ablation in people with drug-refractory atrial fibrillation and found no difference in efficacy after a year. Whether pulsed field ablation is safer is still unclear: the risk of atrio-oesophageal fistula with catheter ablation was only recognised six years after the procedure was developed.
N Engl J Med doi:10.1056/NEJMoa2307291
Nirmatrelvir-ritonavir to prevent post-covid conditions
For those with confirmed covid-19 at the highest risk of hospital admission, nirmatrelvir-ritonavir is recommended by WHO guidelines due to a reduction in mortality and hospital admissions in these patients. A retrospective target trial emulation study sought to find out if it might also help prevent post-covid conditions too. It matched US veterans who had had covid-19 and were at high risk of developing severe covid-19 and had received nirmatrelvir-ritonavir with patients who didn’t receive treatment, and compared the incident of 31 post-covid conditions between them. Assessing 31 outcomes means you’re likely to get one or two positive findings due to chance, which is one possible explanation for the findings of this study: rates of venous thromboembolism and pulmonary embolism were lower in the nirmatrelvir-ritonavir group, but there was no difference in any of the 29 other outcomes.
Ann Intern Med doi:10.7326/M23-1394
Reducing bleeding in small intestinal angiodysplasia
Somatostatin analogues such as octreotide are often used as medical treatment for small intestinal angiodysplasias. A randomised controlled trial suggests that thalidomide may be an alternative option, although one with common side effects (including limb numbness and peripheral oedema) and the well known risks of teratogenicity. The study randomised 150 people who had confirmed small intestinal angiodysplasia and at least four bleeding episodes in the previous year. Those allocated to receive a four month course of daily oral thalidomide were more likely to see a reduction of at least 50% in the number of bleeding episodes in the subsequent year (68.6% for 100 mg a day, 51.0% for 50 mg a day) than those in the placebo group (16.0%).
N Engl J Med doi:10.1056/NEJMoa2303706