Temporal Pattern of Ischemic Events in Relation to Dual Antiplatelet Therapy in Patients With Unprotected Left Main Coronary Artery Stenosis Undergoing Percutaneous Coronary Intervention

Received 9 October 2008; received in revised form 1 December 2008; accepted 2 December 2008.

Objectives

The aim of this study was to investigate whether there is a temporal pattern of ischemic events in relation to dual antiplatelet therapy in patients with unprotected left main coronary artery (ULMCA) stenosis treated with percutaneous coronary intervention (PCI).

Background

Identifying which periods during follow-up of patients with ULMCA stenosis treated with PCI are associated with higher risk of clinical events might help to improve therapeutic strategies.

Methods

We analyzed data from 15 centers involved in an observational study conducted by the Italian Society of Invasive Cardiology on patients with ULMCA stenosis treated with PCI. Eight hundred ninety-four patients were enrolled.

Results

At 30-day follow-up, the rate of cardiac mortality and myocardial infarction (MI) was 5.4%. In patients still taking dual antiplatelet therapy, the adjusted incidence rate ratio/10,000 patient-days of the combination of cardiac mortality and MI in the 31- to 180-day interval compared with the 181- to 360-day interval after PCI was 3.64 (p = 0.035). This risk was particularly high in patients with acute coronary syndromes. After stopping clopidogrel, the adjusted incidence rate ratio of cardiac mortality and MI in the 0- to 90-day interval compared with the 91- to 180-day interval was 4.20 (p = 0.009).

Conclusions

In patients with ULMCA stenosis taking dual antiplatelet therapy there is an increased hazard of cardiac mortality and MI between 31 and 180 days compared with 181 to 360 days. Furthermore, there is an increased hazard of cardiac mortality and MI in the first 90 days after stopping clopidogrel.

Key Words: antiplatelet therapy, left main, stent

Abbreviations and Acronyms: MI, myocardial infarction, PCI, percutaneous coronary intervention, ULMCA, unprotected left main coronary artery

⁎ Istituto di Cardiologia, Policlinico S. Orsola, Università di Bologna, Bologna, Italy

† Dipartimento di Cardiologia, Ospedale Ferrarotto, Università di Catania, Catania, Italy

‡ Divisione di Cardiologia, Università di Torino, Torino, Italy

§ Dipartimento Cardiovascolare, Ospedale Careggi, Università di Firenze, Firenze, Italy

∥ Dipartimento di Cardiologia, Ospedale S. Maria delle Croci, Ravenna, Ravenna, Italy

¶ Centro Emocolumbus, Milano, Italy

# Dipartimento di Cardiologia, Ospedale degli Infermi, Rimini, Italy

⁎⁎ Centro Cardiologico Monzino, Università di Milano, Milano, Italy

†† Dipartimento di Cardiologia, Clinica Mediterranea, Napoli, Italy

‡‡ Unità Operativa di Cardiologia, Azienda Ospedaliero-Universitaria, Parma, Italy

§§ Dipartimento di Cardiologia, Azienda Ospedaliera, Mestre, Italy

∥∥ Dipartimento di Scienze Cardiovascolari, Università di Padova, Padova, Italy

¶¶ Cardiovascular Interventional Radiology Department, IRCCS Policlinico S. Donato, S. Donato Milanese, Milano, Italy

## Dipartimento Cardio-Toracico, Ospedale Cisanello, Pisa, Italy

⁎⁎⁎ Dipartimento Cardiovascolare, Ospedale S. Donato, Arezzo, Italy

††† Dipartimento di Cardiologia, Hesperia Hospital, Modena, Italy

‡‡‡ Istituto Fisiologia Clinica, CNR, Massa, Italy

§§§ Dipartimento Cardiovascolare, Ospedale Cervello, Palermo, Italy

∥∥∥ Dipartimento di Malattie Cardiovascolari, Ospedale Civile, Legnano, Italy

Reprint requests and correspondence: Dr. Tullio Palmerini, Istituto di Cardiologia, Università di Bologna, Policlinico S. Orsola, Via Massarenti 9, 40 138 Bologna, Italy.

Dr. Ramondo is a Tutor of CoreValve.

PII: S0735-1097(09)00167-3

doi:10.1016/j.jacc.2008.12.034

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