Prognostic impact of high residual platelet reactivity after chronic total occlusion percutaneous coronary intervention in patients with diabetes mellitus

•Diabetes is frequently associated with coronary multivessel disease and CTO.•We examined the prognostic impact of HRPR in diabetic patients treated with CTO-PCI.•HRPR was defined as residual platelet aggregation by 10 μmol/L ADP test ≥ 70%.•HRPR and insulin therapy are independently associated with risk of mortality.•HRPR increases the prognostic value of the model with validate predictors of death.

BackgroundThe study sought to determine the impact of high residual platelet reactivity (HRPR) on long-term cardiac mortality in diabetic patients treated with PCI for CTO. No data exist about the impact of HRPR after 600 mg clopidogrel loading on long-term clinical outcome in patients with diabetes mellitus and treated with percutaneous coronary angioplasty (PCI) for chronic total occlusion (CTO).MethodsFrom the Florence CTO-PCI registry, we identified consecutive diabetic patients with available in vitro platelet reactivity assessment by light transmittance aggregometry after a loading dose of 600 mg of clopidogrel. HRPR was defined as residual platelet aggregation by 10 μmol/L ADP test ≥ 70%. The primary end point of the study was long-term cardiac mortality.ResultsTwo-hundred and three diabetic patients underwent CTO-PCI. The incidence of HRPR was 23%. The 3-year cardiac survival was lower in the HRPR group than the low residual platelet reactivity (LRPR) group (70 ± 7% and 92 ± 3%, respectively; p = 0.001). Within the oral antidiabetic patients there were no significant differences in long-term survival between HRPR and LRPR groups. Conversely, the association of insulin therapy and HRPR was related to a dramatic decrease in survival compared to the LRPR group (34 ± 14% vs. 89 ± 4%; p < 0.001). At multivariable analysis insulin therapy (HR 4.31; p = 0.001) and HRPR (HR 3.26; p = 0.004) were significantly related to long-term mortality, while completeness of revascularization was inversely related to cardiac mortality (HR 0.40; p = 0.029).ConclusionHRPR is a strong marker of increased risk of cardiac death in patients with DM who underwent PCI for CTO.

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