Elective PCI ischemic preconditioning: Clinical gains durable up to six years

Cambridge, UK - The early clinical benefits of remote ischemic preconditioning prior to elective coronary stenting have a long reach, suggests an six-year follow-up analysis of a randomized trial^[1]. The previous results included reductions in procedural symptoms, troponin rises, and ECG evidence of ischemia in patients who had undergone the simple procedure before their PCI^[2].

Those who had the ischemic preconditioning intervention, in which a cuff inflated to 200 mm Hg constricts an upper arm for several minutes, several times, soon before PCI, had also shown a significant reduction in major adverse cardiac and cerebral events (MACCE) at six months, heartwire reported four years ago.

Now, analysis of almost 90% of the original cohort randomized in the Cardiac Remote Ischemic Preconditioning in Coronary Stenting (CRISP Stent) study suggests that the low-tech procedure's early event-free-survival benefit is durable for at least up to six years (mean 4.33 years).

"Patients undergoing elective PCI should be considered for remote ischemic preconditioning before the procedure, in an attempt to reduce postprocedural troponin release and thus abrogate MACCE at both short- and long-term follow-up," write the authors, led by Dr William R Davies (Papworth Hospital, Cambridge, UK), in a Circulation: Cardiovascular Interventions report published online May 21, 2013.

At six months, the rate of MACCE (all-cause mortality, nonfatal MI, transient ischemic attack or stroke, and heart failure requiring hospital admission) had been significantly lower in the ischemic-preconditioning group (hazard ratio [HR] 0.28, 95% CI 0.12-0.82; p=0.018). The benefit was driven by their lower rate of admission for ACS/nonfatal MI. By 30 months, the benefit remained significant (HR 0.48, 95% CI 0.24-0.97; p=0.041).

By the six-year follow-up, MACCE had occurred in about 31% of patients; those experiencing events had shown significantly higher mean 24-hour cardiac troponin-I levels, 2.07 ng/mL, compared with 0.91 ng/mL for those without events (p=0.05). The MACCE benefit from ischemic preconditioning persisted compared with earlier evaluations (HR 0.58, 95% CI 0.35-0.97; p=0.039).

The mean time between the end of the final cuff inflation and PCI was significantly higher in patients who ultimately had a MACCE, 76.6 minutes, vs 58.9 minutes (p=0.024) for those who were MACCE-free, the group reports.

"It is recognized that the early protection from remote ischemic preconditioning wanes within an hour or two of the initial stimulus. Our troponin and MACCE data confirm this and emphasize the importance of expeditious PCI after completion of remote ischemic preconditioning."

Heartwire from Medscape © 2013 

Cite this: Elective PCI ischemic preconditioning: Clinical gains durable up to six years - Medscape - May 24, 2013.