How often should you test for Legionella?
TAILOR-PCI was a 7-year 5,300-patient clinical trial of precision medicine for cardiac stent patients, funded by Mayo Clinic and the National Institutes of Health (NIH). Spartan’s FDA-cleared rapid RX CYP2C19 genotyping test was used to personalize antiplatelet therapy with clopidogrel or ticagrelor. The results were published on August 25, 2020 in the Journal of the American Medical Association (JAMA). The results showed that:
• Genotype-guided therapy resulted in 34% fewer adverse events after 12 months such as death, stroke, second heart attack, and stent thrombosis.
• Genotype-guided therapy resulted in 79% fewer adverse events in the first three months. According to principal investigator Dr. Naveen Pereira: “This finding suggests that the lion’s share of the benefit of genetically guided therapy may occur during this high-risk period.” 
Did TAILOR-PCI meet its goal?
TAILOR-PCI did not meet its goal of reducing adverse events by 50% over 12 months. However, it did reduce adverse events by 34% over that time. This 34% reduction had a p value of 0.056, which means the trial missed the threshold for statistical significance by only 0.002%. When looking at the first three months, there was a 79% reduction in adverse events (p value of 0.001). This is a significant result.
Genotype-guided therapy allowed approximately 70% of patients to take clopidogrel, which is less expensive than ticagrelor and has fewer side effects such as shortness of breath and bleeding.
What does the medical community think?
Patrick O’Gara, MD and Professor of Medicine at Harvard Medical School, said that he “would hate for people to focus unnecessarily on the fact that you missed your primary endpoint by a hundredth of a percentage point and not sort of speak to the big picture about how we can make this genetic testing more widely available at the point of care in a more accurate way that actually informs clinical decision making among our interventional and general cardiology colleagues. It just makes too much sense to ignore this potential.” 
How does Spartan’s genotyping test compare to the current treatment methods for cardiac stent patients?
From another statistical perspective, the 34% reduction in adverse events corresponded to a Number Needed to Treat (NNT) of 55. NNT is the number of patients you need to treat to prevent one adverse event. So you would need to test 55 patients with Spartan’s non-invasive test to prevent one death/stroke/second heart attack/stent thrombosis. For comparison, Lipitor is the most widely-prescribed anti-cholesterol drug. Lipitor’s NNT is 100, which means 100 people have to take Lipitor for over 3 years to spare one person a heart attack. The other 99 people get no measurable benefit, statistically speaking.
For more information on how Spartan is helping to change the course of precision medicine, visit www.spartanbio.com/products/medical/cyp2c19/
Which Test Are You Looking For?