Clinical profile of ACS patients treated with prasugrel, clopidogrel varies in US

SAN DIEGO — The clinical profile of patients with ACS treated with prasugrel as compared with clopidogrel differs substantially across U.S. academic medical centers, according to real-world data from the PROMETHEUS study.

Patients treated with prasugrel had a lower burden of risk for ischemic and hemorrhagic events than those treated with clopidogrel, Usman Baber, MD, MS, reported at the Society for Cardiovascular Angiography and Interventions Scientific Sessions.

Usman Baber

Baber and colleagues conducted a retrospective cohort study of 19,914 patients who underwent PCI with stents at eight U.S. academic medical centers from January 2010 to June 2013. The researchers collected baseline, clinical procedural and outcome data on patients undergoing PCI from institutional databases maintained at each center. For this analysis, patients were categorized based on use of clopidogrel or prasugrel (Effient, Daiichi Sankyo/Eli Lilly) at the time of PCI.

“Data examining the safety and efficacy profile of prasugrel in nonrandomized patients presenting across the entire clinical spectrum of ACS remains limited [and] the overall frequency and determinants of prasugrel use remain poorly characterized,” Baber, assistant professor of cardiology at Mount Sinai Hospital in New York, said during a presentation.

Twenty percent of patients (n = 4,058) received prasugrel at the time of PCI and the rest received clopidogrel.

The primary efficacy endpoint, major adverse cardiac events at 90 days after index PCI, occurred in 9.6% of clopidogrel recipients compared with 5.7% who received prasugrel (P < .001). This translated to a 42% relative risk reduction for overall MACE in favor of prasugrel, according to the researchers. After adjustment for baseline differences, the relative reduction was attenuated to a nonsignificant 11% benefit.

After adjustment, the primary safety endpoint of postprocedural or clinically overt bleeding requiring hospitalization was not significantly different between the prasugrel and clopidogrel groups (3.8% vs. 4%; P = .52).

“Although in this study prasugrel use was associated with lower rates of ischemic adverse events, the magnitude of benefit attenuated and was no longer statistically significant after adjusting for baseline differences. Analogously, lack of adjusted bleeding difference with prasugrel may reflect selection of patients at very low risk for hemorrhagic complications,” Baber said.

The results also suggested that prasugrel is more likely to be given to lower-risk patients undergoing PCI compared with clopidogrel. Patients who received prasugrel tended to be younger, more often male, and had less renal dysfunction and anemia compared with patients who received clopidogrel. However, patients who received prasugrel were more likely to present with STEMI and receive longer stents.

“The overall burden of risk factors for both ischemic and hemorrhagic events are much lower in patients treated with prasugrel,” Baber said. “Recalibrating ‘real-world’ use of prasugrel to better approximate a patient’s ischemic risk may yield a more appreciable therapeutic benefit, a hypothesis that warrants prospective evaluation.” – by Katie Kalvaitis

Reference:

Baber U, et al. Late-Breaking Clinical Trials. Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions; May 6-9, 2015; San Diego.

Disclosure: Baber reports no relevant financial disclosures.