Monitoring persistent platelet reactivity in patients with unprotected left main stenting

This study sought to determine the rate and potential clinical impact of persistent platelet reactivity (PPR) in unprotected left main (ULMD) stenting.

PPR under aspirin or thienopyridines is associated with acute events after angioplasty.

We prospectively included 125 patients referred for ULMD stenting. For the first 64 patients (ALMA-1), angioplasty was performed under aspirin and clopidogrel without platelet reactivity assessment. For the last 61 patients (ALMA-2), platelet reactivity was assessed before angioplasty: in patients with aspirin-related PPR, aspirin twice daily was given and in those with clopidogrel-related PPR, clopidogrel double dose or prasugrel was used.

Overall, patients' mean age was 69 ± 13 years, 37% were diabetic, and 37% had non-ST segment elevation myocardial infarction (NSTEMI). Patients' characteristics were similar in both studies with isolated left main in 14% and associated with 1-, 2-, or 3-vessel disease in 23%, 36%, and 27%, respectively. Mean SYNTAX score was 23 ± 9. Procedural characteristics were similar using provisional T stenting in 69%, T stenting in 27%, and other techniques in 4%. In ALMA-2, 28% patients had PPR for aspirin, 29% for clopidogrel, and 8% for both. Aspirin twice daily was given in 28% of patients, clopidogrel double dose in 26%, and prasugrel in 31%. The rate of 1-year major adverse cardiovascular and cerebrovascular events (MACCE) was lower in ALMA-2 versus ALMA-1 (8.2% vs. 20.8%; P = 0.04) as a composite end-point of cardiovascular death or stent thrombosis (0.0% vs. 8.3%; P = 0.02).

PPR under aspirin and thienopyridines is frequent in ULMD stenting and could be related to subsequent major events.