SOLACI | Latin American Society of Interventional Cardiology

Courtesy of Dr. Santiago F. Coroleu.

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel after percutaneous coronary intervention (PCI) reduces the risk for coronary thrombotic events (CTEs) at the expense of increasing risk for major bleeding (MB). However, the lack of information to accurately predict the occurrence of each event in out-of-hospital patients under long-term follow-up presents a significant problem.

The aim of this study was the development and validation of models to predict risks for out-of-hospital thrombotic and bleeding events after a PCI with drug-eluting stents (DES) in a real-world population.

Using data from 4190 patients treated with DES and enrolled in the PARIS (Patterns of Non-Adherence to Antiplatelet Regimen in Stented Patients) registry, separate risk scores were developed to predict CTEs (defined as stent thrombosis or acute myocardial infarction) and MB (defined as the occurrence of a Bleeding Academic Research Consortium type 3 or 5 bleed). Furthermore, external validation of both risk scores was carried out through the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) registry.

Over 2 years, CTEs occurred in 151 patients (3.8%) and MB in 133 (3.3%).

Independent predictors of CTEs included the following:

Acute coronary syndrome
Prior revascularization
Diabetes mellitus
Renal failure
Current smoking

Independent predictors of MB included the following:

Old age
Low or high body mass index
Triple antiplatelet therapy at discharge
Anemia
Current smoking
Renal failure

Each model displayed moderate levels of discrimination and adequate calibration.

Conclusion

Simple risk scores of baseline clinical variables from patients may be useful to correctly predict risks for thrombotic and bleeding events after a PCI with DES, thereby facilitating clinical decisions surrounding the optimal duration of dual antiplatelet therapy (DAPT).

Editorial

This study is based mainly on the fact that most risk scores for thrombotic and bleeding events after a PCI with DES assess such risks fundamentally during the hospitalization and short-term follow-up of patients enrolled in randomized clinical trials. In consequence, information available as regards longer follow-up and “real-world” populations is scarce.

Since the usefulness of extended DAPT has been subject of discussion and revision in the last years, this study was created with the intention of generating risk scores for the incidence of CTEs and MB in outpatients, people “in the real world” treated with DES under long-term follow-up.

The PARIS registry was an observational prospective multicenter registry kept in Europe and the United States during 2009 and 2010, which enrolled 4190 patients who underwent a PCI with DES (second-generation, mostly), with a 3-, 6-, 12- and 24-month follow-up.

Initially, obtained data facilitated the assessment of independent CTE and MB predictors, which were subsequently used in the creation of risk scores for both events. The validation of those risk scores was carried out through the ADAPT-DES registry, given the similarities among populations in both registries (PCI with DES and a 2-year follow-up).

Of 4.190 enrolled patients, 151 presented CTEs and 133 presented MB.

Independent CTE predictors included the following: 1) old age, 2) BMI ≤25 and ≥35 kg/m², 3) anemia, 4) triple antiplatelet therapy at discharge, 5) current smoking, and 6) renal failure.

Independent MB predictors included the following: 1) diabetes mellitus, 2) acute coronary syndrome, 3) prior revascularization, 4) current smoking, and 5) renal failure.

Those variables were used in the creation of risk scores, and patients were divided according to their LOW, INTERMEDIATE or HIGH risk for thrombosis or bleeding (around 50%, 40%, and 10% of the population, respectively, for both events). Those values were correctly validated through the ADAPT-DES registry, for both CTEs and MB.

Additionally, authors emphasize the success of the simultaneous application of both scores to the identification of patients who might benefit from long-term DAPT and those who might be harmed by it.

Previous scores, with short-term follow-up (or follow-up during hospitalization), include data related to the procedure (stent length and number, type of lesion, etc.). However, this study showed that, in the long term, clinical variables are more significant as regards the incidence of CTEs and (consequently) the decision of extending DAPT.

This study (and the risk scores obtained therefrom) is limited by its nature as a non-experimental, non-randomized study. Other limitations include the exclusive use of clopidogrel (which means that results cannot be extrapolated to new Y2P12 inhibitors), the lack of measurement of possibly significant variables (such as left ventricular function and platelet reactivity), and the fact that the DAPT was interrupted or extended exclusively at the discretion of the treating physician.

As a conclusion, simple risk scores of baseline clinical variables from patients may be useful to correctly predict risks for thrombotic and bleeding events after a PCI with DES, thereby facilitating clinical decisions surrounding the optimal duration of dual antiplatelet therapy.

Original title: Coronary Thrombosis and Major Bleeding After PCI With Drug-Eluting Stents ; Risk Scores From PARIS.

Reference: Usman Baber et al. J Am Coll Cardiol. 2016 May 17;67(19):2224-34.

Courtesy of Dr. Santiago F. Coroleu. Interventional Cardiology. Santiago del Estero Cardiology Institute, Argentina.