Chinese study finds it common, not associated with longer-term risk
Thrombocytopenia wasn’t linked to long-term risks from elective percutaneous coronary intervention (PCI), one center reported.
A low platelet count of less than 150 × 109/L was common, seen in about 1 in 8 (12.76%) of the 9,897 consecutive PCI patients at a Chinese hospital in the study by Kefei Dou, MD, PhD, of Fuwai Hospital in Beijing, and colleagues.
Similar adverse event rates over 30 months were observed whether patients had normal or low platelet counts at baseline:
- Death: 1.2% vs. 1.0% (P=0.5148)
- Cardiac death: 0.6% vs. 0.6% (P=0.9497)
- Myocardial infarction (MI): 1.1% vs. 0.7% (P=0.2212)
- Target vessel revascularization: 5.3% vs. 4.6% (P=0.3106)
- Bleeding: 6.7% vs. 6.6% (P=0.8700)
- Ischemic stroke: 1.5% vs. 1.7% (P=0.7542)
- Major adverse cardiovascular events: 6.8% vs. 5.9% (P=0.3106)
Thrombocytopenia was independently associated with advanced age, male sex, prior PCI, prior MI, and diabetes. The report was published online in Catheterization and Cardiovascular Interventions.
“Although baseline thrombocytopenia was common among patients who underwent elective PCI, it did not appear to have a clinically significant effect on long-term adverse outcomes, [in] particular bleeding risk,” Dou’s group said, noting that not one of the 91 patients with moderate or severe thrombocytopenia experienced major bleeding.
These good outcomes for PCI patients with thrombocytopenia contrasted with the strong association with ischemic events in the ACUITY and HORIZONS-AMI trials, the investigators noted. This may be because the Chinese study was unique in two ways: study population and duration of antiplatelet therapy.
“The previous studies enrolled patients with acute MI or high-risk ACS [acute coronary syndrome]. In our study, we enrolled patients undergoing elective PCI who had higher rates of stable angina. Patients with preoperative blood system diseases, severe liver disease, or autoimmune disease were not eligible for elective PCI procedure and thus would have been excluded from the study population,” Dou and colleagues said.
The lower-risk population also meant this group could better tolerate antiplatelet therapy for longer.
Nearly all patients in the study got aspirin and clopidogrel (Plavix). Given the findings, 12 months of dual antiplatelet therapy (DAPT) may be safe for patients with thrombocytopenia who have no hematologic diseases or history of gastrointestinal bleeding, the authors said.
In general, operators can balance thrombotic and bleeding risks during PCI by using a radial approach with second-generation drug-eluting stents, as well as opting for proton pump inhibitors while avoiding glycoprotein IIb-IIIa inhibitors, the authors suggested. Among the P2Y12 inhibitors, clopidogrel would be the “agent of choice” in patients with thrombocytopenia getting DAPT, the authors added.
Dou and colleagues acknowledged that the limitations to their post hoc analysis included having relatively few patients with moderate or severe thrombocytopenia and not systematically recording the cause of platelet dysfunction.
Dou’s group reported no relevant disclosures.
Catheterization and Cardiovascular Interventions
Liu S, et al. “Impact of baseline thrombocytopenia on the long-term outcome of patients undergoing elective percutaneous coronary intervention: an analysis of 9,897 consecutive patients” Catheter Cardiovasc Interv 2018; DOI: 10.1002/ccd.28030.