A prototype artificial intelligence (AI) tool showed that just
three inputs had the most predictive power for discerning which patients with
COVID-19, the illness caused by the novel coronavirus SARS-CoV-2, would likely
develop acute respiratory distress syndrome (ARDS) (Comput Mater Con
2020;63:537-51). Based on data from 53 patients treated at two hospitals in
China, this predictive analytics system found that elevations in alanine
aminotransferase (ALT) and hemoglobin, along with patient-reported myalgia
predicted risk of ARDS with up to 80% accuracy.
Surprisingly, many of the
clinical features associated with COVID-19 such as ground glass opacities on
chest computed tomography, fever, cough, lymphopenia, and dyspnea did not
distinguish risk of disease progression and were not highly predictive.
Patients’ viral load (cycle threshold) also did not prove to be
predictive.
Moreover, the patients’ ALT and hemoglobin values were only
modestly elevated. The median ALT value at the time of presentation at hospital
was 24 U/L (range, 15-40.5 U/L; reference range, 9-50 U/L). The median
hemoglobin level was 13.7 g/dL (range, 12.9-14.4 g/dL, reference range,
12.8-16.5 g/dL). Other features, including sex, temperature, age, and levels of
sodium, potassium, and creatinine, and lymphocyte and white blood cell counts,
added modestly to prediction.
“The model highlights that some pieces of
clinical data may be underappreciated by clinicians,” wrote the investigators in
Wenzhou, China, and in New York City. They added that features don’t have to be
causal to be predictive.
In their feature engineering and statistical
analysis, the researchers employed entropy, which measures how much information
a feature encapsulates; information gain—the amount of information acquired
after knowing the value of the feature; Gini index, a measure of the impurity of
a dataset; and Chi-Squared statistics, indicating how dependent two variables
are.
The authors speculated that myalgia “could represent generalized
inflammatory and cytokine response not captured well by other indicators.” The
slightly elevated hemoglobin levels could be linked to smoking, which has been
associated with increased hemoglobin values, or to male sex.
MAJOR
GENETIC TESTING-GUIDED TRIAL FALLS JUST SHORT OF 1-YEAR EVENT END
POINT
The much-anticipated TAILOR-PCI trial assessing genetic
testing to guide antiplatelet therapy after percutaneous cardiovascular
intervention failed to meet its primary end point of a 50% reduction in adverse
cardiovascular events at 1 year. However, the largest trial to explore the
clinical utility of detecting CYP2C19 *2/*3 loss of function allele carriers
prior to starting antiplatelet therapy showed a 34% reduction in a composite of
major cardiovascular events at year 1. TAILOR-PCI also found a statistically
significant 40% drop in the total number of events per patient who received
genetically guided treatment compared with those who received standard therapy.
These outcomes were presented at the virtual American College of
Cardiology/World Congress of Cardiology meeting (20-LB-20309-ACC).
“Although
these results fell short of the effect size that we predicted, they nevertheless
provide a signal that offers support for the benefit of genetically guided
therapy,” said co-principal investigator Naveen Pereira, MD, professor of
medicine at the Mayo Clinic in Rochester, Minnesota.
In a post hoc analysis,
the researchers found a nearly 80% reduction in the rate of adverse events in
the first 3 months of treatment in participants who received genetically guided
care versus those who received standard care.
Subjects were randomized to
receive either standard care—75 mg daily of clopidogrel—or genetic
testing-guided care. Those who were determined through genetic testing to be
CYP2C19 *2/*3 carriers (35%) received 90 mg of ticagrelor twice daily;
otherwise, participants in the genetic testing arm of the trial received
clopidogrel. There were 1.6% major or minor bleeding events at the end of 1 year
in participants in the standard care arm and 1.9% in carriers in the
guided-treatment group.
LITTLE CONCORDANCE AMONG NONINVASIVE METHODS
FOR IDENTIFYING NASH
Three noninvasive methods for identifying
patients with nonalcoholic steatohepatitis (NASH) agree in only 18% of cases,
under-scoring the need for better noninvasive means of recognizing this
condition, according to an abstract accepted for the Endocrine Society’s annual
meeting (SUN-606).
The investigators used data from the National Health and
Nutrition Examination Survey III (NHANES III) to compare three noninvasive
methods of identifying NASH: the NASH liver fat score, the HAIR score, and the
Gholam score.
The HAIR score incorporates the presence of hypertension,
alanine transaminase (ALT) levels, and insulin resistance. The NASH liver fat
score is based on the presence of metabolic syndrome, type 2 diabetes, and
levels of serum insulin, ALT, and aspartate aminotransferase (AST), while the
Gholam score uses AST and a diagnosis of type 2 diabetes.
The investigators
identified NHANES III participants who had moderate to severe hepatic steatosis,
as determined by ultrasound. In all 1,236 subjects were determined to have NASH
by at least one noninvasive method, but the three methods all identified NASH in
just 18% of cases. Two methods agreed in 20% of cases.
The three methods all
identified significant risk factors for NASH as being overweight or obese,
having elevated AST or ALT levels, and having raised C-peptide, serum glucose,
or serum triglycer-ide levels. However, the methods disagreed on the
significance of other risk factors.