Increased Risk Associated with Premature Cessation of Dual Antiplatelet Therapy Due to Patient Non-Adherence, Not Physician-Recommendation

Results of the PARIS Registry reported at TCT 2012


November 30, 2012

November 30, 2012 — A large observational study found the increased risk associated with dual antiplatelet therapy cessation after percutaneous coronary intervention (PCI) is tied to patient non-adherence, as opposed to physician-recommended discontinuation. Results of the PARIS registry were presented at the 24th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium.

Dual antiplatelet therapy (DAPT), using aspirin and a second anticlotting medication, is recommended to reduce the risk of blood clots following the implantation of a stent. Current guidelines recommend 30 days DAPT following placement of a bare-metal (BMS) stent and one year following placement of a drug-eluting stent (DES).

The PARIS Registry was a multicenter, observational study of 5,033 patients receiving PCI with stents. In this study, DAPT cessation was uniquely categorized due to the specific reasons for discontinuation (for example, due to physician recommendations versus patient non-adherence for other reasons). Using these data, researchers examined the association between DAPT use and subsequent major adverse cardiovascular events (MACE).

Among patients stopping DAPT at one year, most (approximately 62 percent) were classified as non-adherent by the pre-specified PARIS criteria. The incidence of MACE at one-year was higher in non-adherent patients than in those who discontinued therapy on physician recommendation (13.7 percent vs. 6.5 percent, p=<0.001). Those patients who remained on DAPT had a similar rate of adverse events as those who discontinued therapy on physician recommendation (6.5 percent). The PARIS investigators also observed that DAPT cessation within one year was associated with an increased risk for all adverse events, an association that was strongest in the first seven days and lessened after 30 days.

“Results of the PARIS registry indicate that the increased risk associated with DAPT cessation is entirely attributable to non-adherence as physician-guided discontinuation did not increase adverse events,” said the lead investigator, Roxana Mehran, M.D. Mehran is professor of Medicine at Mount Sinai School of Medicine and director of Interventional Cardiovascular Research and Clinical Trials at the Zena and Michael A. Wiener Cardiovascular Institute. She also serves as chief scientific officer of the CRF Clinical Trials Center.

“These findings suggest that the risks associated with DAPT cessation following PCI are not uniform and varies by underlying mode, a novel finding that might influence practice patterns and risk assessment in post-PCI patients stopping DAPT,” said Mehran.

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