Less than 30% of heart attack patients treated with cangrelor received the treatment in a way that was consistent with established protocols and the drug’s FDA labeling, according to new research from the Duke Clinical Research Institute using the CAMEO registry.
The assessment using the Cangrelor in Acute Myocardial Infarction: Effectiveness and Outcomes (CAMEO) registry, was sponsored by Chiesi USA and sought to understand which patients were being selected for treatment using cangrelor and how its use in real-world settings compares to established protocols. “Cangrelor Use Patterns and Transition to Oral P2Y12 Inhibitors among Patients with Myocardial Infarction: Initial Results from the CAMEO Registry” was presented by Jennifer Rymer, MD, co-investigator and DCRI faculty member, at the American College of Cardiology Scientific Session & Expo on April 4. The study’s primary investigator was Tracy Wang, MD, DCRI faculty member and professor in the Duke School of Medicine Division of Cardiology.
Cangrelor is an intravenous P2Y12 receptor inhibitor used to inhibit adenosine diphosphate-induced platelet aggregation in post-myocardial infarction (MI) patients. Clinical trials revealed it can lower the risk of ischemia-driven revascularization, stent thrombosis, heart attacks, and death.
Evaluation of anonymized data from more than 1,000 post-MI patients at nine health systems nationwide revealed a wide variation of cangrelor’s clinical use and the way providers transitioned patients to oral P2Y12 inhibitors afterward.
Only 27% of patients received cangrelor according to the protocols established in clinical trials and consistent with FDA labeling. Patients who received the treatment according to the FDA labeling had numerically less bleeding or major adverse cardiovascular events (MACE), a finding that will be explored further as the patients continue to accrue in the CAMEO registry.
Although cangrelor is an approved therapy used nationwide, this is the first study to examine how it’s being used in clinical settings in various health care systems.
“We’re not doing it as they did it in the trials, or, for that matter what the label says. We’re using it suboptimally and we can do better, and that’s what the project is telling us so far,” said Magnus Ohman, MD, a senior investigator with the DCRI, and chief of the project’s steering committee.
Recommended dosage is a 30 mcg/kg IV bolus followed by a 4 mcg/kg/min IV infusion. A corresponding oral P2Y12 platelet inhibitor is recommended during or immediately following the patient’s cangrelor infusion, depending on the inhibitor used.
However, the study found there was typically an extended delay in the patient receiving the oral P2Y12 inhibitor clopidogrel following the cangrelor.
“What that means is the patient has a significant amount of time – hours (in many cases) – in which they have no anti-platelet agent that’s helping to keep their stent open,” Rymer said. “It’s really critical because some patients may be OK, but some patients may have potentially life-threatening stent thrombosis that occurs as a result.”
Although transition time from the intravenous treatment to the oral P2Y12 inhibitor is crucial, in the clinical setting, a number of variables – from how many patients require care at a given time to the care team’s understanding of cangrelor – can affect it.
Researchers hope that the study provides better information for health care providers on cangrelor’s use and helps improve patient outcomes.
The study included two phases. Phase I observed the treatment of 482 MI patients treated with any P2Y12 inhibitor to better understand cangrelor’s use by hospital. Phase II reviewed 873 MI patients including those who were and were not treated with cangrelor at a 2:1 ratio.
“One site used cangrelor in 6% of their cases, while another site used it in 100% of cases, another used it 92%,” Rymer said. “So, there’s wide, wide differences in how cangrelor is being used.”
The registry is projected to enroll 3,000 MI patients by the end of the year. Future studies plan to assess changes in the way cangrelor is administered resulting from this information and to better understand cangrelor use in bypass patients and use associated with opiates.