Cilostazol as bridging therapy warrants further research

by Payam Dehghani, MD, FRCP(C), FACC, FSCAI

SAN DIEGO — The most quoted research publications are those that address clinically frustrating scenarios for which we have no answer. Charles Laham, MD, FSCAI, and colleagues attempted to answer such a question with the OUTSIDE START study: That is, what can we do for patients who require interruption to dual antiplatelet therapy after PCI due to urgent and unavoidable surgeries?

In fact, at the Society for Cardiovascular Angiography and Interventions Scientific Sessions, Dr. Laham admitted that the OUTSIDE START study was not intended as research, but rather out of clinical necessity 8 years ago (luckily, he consented all patients, thinking he may publish this experience at a later stage, he said).

Payam Dehghani

As recommendations for optimal dual antiplatelet therapy (DAPT) duration have been and continue to be a moving target, the investigators bridged patients requiring interruption with off-label use of cilostazol in the perioperative period for varying durations of time. While cilostazol has never been studied in this setting, there is at least some biologic plausibility for its use in this scenario. It is a phosphodiesterase inhibitor approved for treatment of intermittent claudication with only modest benefit and is known to reversibly inhibit platelet activation and aggregation without any appreciable increase in bleeding risk. Although the data from the OUTSIDE START study presented at the Society for Cardiovascular Angiography and Interventions Scientific Sessions were difficult to follow, in short, of roughly 170 patients who required interruption due to an emergent procedure and were bridged successfully with cilostazol, there were no thrombotic or bleeding events.

It goes without saying that there are significant limitations to this retrospective study. The dosage of cilostazol was not the same in all patients; aspirin use was not constant; cilostazol was used in varying durations, from 5 days to 5 years; standard definitions of bleeding and thrombotic events were not used; there was no independent adjudication committee; the emergent surgeries were of varying urgent profiles; and the nature of PCI was of varying risk profiles, from left main bifurcation interventions to simple type A lesions.

The biggest take-away message from this hypothesis-generating trial is that we have a potential medication with biologic plausibility that should be tested in a well-controlled, randomized, prospective trial. However, given the patient population at hand, it may be difficult to enroll such patients.

What are your thoughts on the use of cilostazol in this patient population and setting? Let us know by commenting on this Eye on Intervention blog.

Payam Dehghani, MD, FRCP(C), FACC, FSCAI, is a SCAI 2015-2017 Emerging Leader Mentorship fellow; an interventional cardiologist within the Regina Qu’Appelle Health Region; director of the Adults with Structural Heart Disease Clinic; clinical co-director of the Prairie Vascular Research Network; and assistant professor at the University of Saskatchewan, Canada.

Disclosure: Dehghani reports no relevant financial disclosures.