A prespecified analysis of total events (rather than just analysis of first event per patient) showed a 40% reduction in the genotyped group (HR, 0.60; 95% CI, 0.41 - 0.89; P = .011).
“Multiple adverse events represent a higher burden on the patient, so it is encouraging to see a significant reduction in cumulative events with genetically guided therapy,” Pereira said.
There was no difference in the safety endpoint of TIMI major bleeding or minor bleeding between the two groups: 1.9% in the genetically guided group vs 1.6% in the conventional treatment group.
The results did not differ between various subgroups in the trial, including race or ethnicity. Although Asian patients have a higher occurrence of the clopidogrel loss-of-function gene, the event risk reductions were similar in Asian and white patients in the study.
Pereira said the study may have been underpowered because of recent improvements in care. When the TAILOR-PCI trial was designed in 2012, around 10% to 12% of patients who received a stent could be expected to have a major adverse event, but during the trial, greater use of drug-coated stents and other treatments significantly reduced the expected rate of adverse events and made it more difficult for the trial to reach its goal of a 50% reduction in adverse events with the number of patients enrolled, he explained.
As part of the discussion, Mehran pointed out that more than 80% of the patients in the trial had acute coronary syndrome (ACS) and yet were being sent home on clopidogrel, which she said she found “daunting.”
“This begs the question of whether they were lower-risk patients and not really the hot unstable ACS patients with large thrombus burden where we see higher event rates,” Mehran commented. She also noted the results must be considered in the new era of platelet monotherapy, where aspirin is being withdrawn, and asked whether clopidogrel monotherapy would be considered safe without aspirin on board.
The researchers are planning a cost-effectiveness analysis of genetically guided therapy based on these data, and they are also continuing to follow patients over the longer term.
The TAILOR-PCI study was funded by the Mayo Clinic in collaboration with the National Heart, Lung, and Blood Institute. Spartan Bioscience Inc supplied the genetic tests used. Pereira reports no relevant disclosures.
American College of Cardiology 2020 Scientific Session (ACC.20)/World Congress of Cardiology. Abstract 20-LB-20309-ACC. Presented March 28, 2020.
This article first appeared on Medscape.com.