Results of the OPTIMIST follow-up study were published online in JAMA.
Researchers, led by Peter A. Dargaville, MD, department of paediatrics, Royal Hobart (Australia) Hospital, found that MIST, which involves administering surfactant via a thin catheter, compared with sham treatment, did not reduce the incidence of death or neurodevelopmental disability (NDD) by 2 years of age.
However, infants who received MIST had lower rates of poor respiratory outcomes during those first 2 years of life.
Study spanned 11 countries
The study was conducted in 33 tertiary neonatal intensive care units (NICUs) in 11 countries, including Australia, Canada, Israel, New Zealand, Qatar, Singapore, Slovenia, the Netherlands, Turkey, the United Kingdom, and the United States.
It included 486 infants 25-28 weeks old supported with CPAP; 453 had follow-up data available and data on the key secondary outcome were available for 434 infants.
The sham treatment consisted of only transient repositioning without airway instruments. Treating clinicians, outcome assessors, and parents were blinded to group status.
No significant difference in deaths, NDD
Death or NDD occurred in 36.3% of the patients in the MIST group and 36.1% in the control group (risk difference, 0%; 95% confidence interval, −7.6% to 7.7%; relative risk, 1.0; 95% confidence interval, 0.81-1.24).
Secondary respiratory outcomes were better in the MIST group:
- Hospitalization with respiratory illness occurred in 25.1% in the MIST group versus 38.2% in the control group (RR, 0.66; 95% CI, 0.54-0.81).
- Parent-reported wheezing or breathing difficulty occurred in 40.6% in the MIST group versus 53.6% in controls (RR, 0.76; 95% CI, 0.63-0.90).
- Asthma diagnosed by a physician was reported in 4.4% and 11.9% of MIST and control-group infants, respectively.
- Reported use of inhaled relievers (beta2 agonists) was 23.9% in the MIST group versus 38.7% in controls.
The previous study of early outcomes of deaths or bronchopulmonary dysplasia (BPD; chronic lung injury in preterm infants) was published by the same group of researchers in 2021.
Important benefit for respiratory health
Suhas G. Kallapur, MD, chief of the divisions of neonatology and developmental biology at University of California, Los Angeles, who was not part of either study, said: “This is one of the largest studies to date examining whether the MIST procedure for surfactant is beneficial in preterm babies born at 25-28 weeks’ gestation.”
Overall, when considering the 2021 and 2023 studies together, it appears that the MIST therapy has important benefits for respiratory health during a NICU stay and in early infancy, even though the primary outcome of death or NDD was not different between the treatment and control groups, Dr. Kallapur said.
“The slight (nonsignificant) increase in deaths in the MIST group was confined to the more immature babies – 25-26 weeks’ gestation at birth,” he pointed out. “In the bigger and more mature babies – 27-28 week gestation infants – the benefits of MIST therapy occurred without any increase in mortality, suggesting that this group of babies may be the group that stands to benefit most from this therapy.”
Dr. Kallapur said new data in the developmental origins of health and disease “now show that the trajectory of respiratory health in infancy is an important determinant of respiratory health into adulthood and older age.”
Therefore, the finding of benefit to respiratory health is particularly important, he said.
He noted that MIST or similar therapy is already in use in many NICUs throughout the world and that those already using it will likely feel vindicated by this study.
“Neonatologists who were on the sidelines will likely see these results – especially childhood respiratory outcomes – as a reason to initiate this procedure in all but the most immature preterm infants,” Dr. Kallapur says.
Dr. Dargaville reports personal fees from AbbVie and Chiesi Farmaceutici and provision of surfactant at reduced cost and support for conference travel from Chiesi Farmaceutici during the conduct of the study; in addition, Dr. Dargaville has been issued a patent for a catheter design. One coauthor reports grants from Chiesi Farmaceutici during the conduct of the study. Another coauthor reports serving as chief investigator for OPTI-SURF, an observational study on United Kingdom neonatal surfactant use in respiratory distress syndrome funded by Chiesi UK outside the submitted work. A third coauthor reports personal fees from Chiesi Farmaceutici outside the submitted work. This study was funded by grants from the Royal Hobart Hospital Research Foundation and the Australian National Health and Medical Research Council. Exogenous surfactant was provided at reduced cost by Chiesi Farmaceutici. Dr. Kallapur has no relevant financial relationships.