The immunosuppressant drug cyclosporine used to be administered to patients prior to receiving a percutaneous coronary intervention (PCI). This kind of surgery is performed for the most severe form of heart attack called in medical circles ST-segment elevation myocardial infarction (STEMI).
A new research has shown that the immunosuppressant drug cyclosporine could not improve in any significant way the clinical outcomes of those receiving a PCI surgery compared to placebo in the rest of the patients. The results of the CIRCUS clinical trial were published in the New England Journal of Medicine and presented simultaneously in a Hot Line session at ESC Congress 2015.
The findings of the study suggest that the drug administered prior to PCI had little or no impact at all on a composite of hospitalization for, all-cause death, or worsening of heart failure, as well as on adverse left ventricular remodeling at one year from the surgical intervention. According to lead investigator Michel Ovize, MD, Ph.D., from Claude Bernard University, in Lyon, France, his research team was surprised and disappointed by their findings.
Previously, there were hopes that the drug cyclosporine can improve cardiac function and reduce infarct size based on substantial experimental evidence that. The research team led by Dr. Ovize has previously published a small-size phase II trial that at that date was suggesting cyclosporine may reduce infarct size in STEMI patients. However, the larger phase III CIRCUS study did not come to confirm the findings of the phase II trial. According to Dr. Ovize, the reason for this discrepancy it is still unclear at the current stage of research.
The study reunited patients undergoing PCI who had anterior STEMI The patients selected were all manifesting complete occlusion of the coronary artery and they were studied within 12 hours of symptom onset. Before coronary PCI, the researchers performed randomly on patients a 2.5 mg/kg intravenous bolus injection of cyclosporine (n=395) or matching placebo (n=396).
The findings of the study have shown a rate of the primary outcome of 59.0% in the cyclosporine group versus 58.1% in the control group. The difference is too small to show any improvement. The scientists also found that other events including unstable angina, recurrent infarction, or stroke are not reduced by cyclosporine and that the drug did not reduce the incidence of separate clinical components of the primary outcome.
According to Professor Ovize, the real-life setting of anterior STEMI could be significantly different from animal models to human patients and the treatment also changed since their previous study. These facts might be among the possible explanations behind the unexpected results of the recent study.
