Impact of baseline thrombocytopenia on outcomes in hospitalizations for acute coronary syndrome and non-elective percutaneous coronary intervention: meta-analysis

Abstract Background Thrombocytopenia's impact on acute coronary syndromes (ACS) outcomes is poorly understood. A systematic review and meta-analysis aim to elucidate its influence on both short-term and long-term clinical endpoints, guiding tailored management strategies for improved patient care. Methods Our meta-analysis is registered on PROSPERO (CRD42024511832). We conducted a systematic search of PubMed and SCOPUS databases up to February 2024, utilizing keywords to identify studies on ACS or non-elective PCI populations with or without baseline thrombocytopenia (TP) reporting on in-hospital and long-term outcomes. Baseline TP was defined as a platelet count less than 150 x 10⁹/L and had to be established before hospitalization or ACS management or intervention. Binary random effects models were used to estimate pooled unadjusted odds ratios (OR) and 95% confidence intervals (CI). Sensitivity analysis was done by the leave-one-out method, and the heterogeneity was assessed with the I² statistics. Results From 2,831 identified studies, 10 were identified as eligible for inclusion in our pooled analysis and included 6,588,688 patients. Thrombocytopenia was associated with higher risks of in-hospital mortality (OR=1.89, 95% CI:1.55-2.30, p<0.01), in-hospital Major adverse cardiovascular events (MACE) (OR=1.99, 95% CI:1.63-2.43, p<0.01), and in-hospital bleeding (OR=2.62, 95% CI:1.89-3.64, p<0.01). Long-term follow-up revealed increased risks of MACE (OR=1.80, 95% CI 1.49-2.18, p<0.01), bleeding (OR=1.63, 95% CI:1.63-2.25, p<0.01), and cardiovascular mortality (OR=2.07, 95% CI:1.76-2.42, p<0.01) with thrombocytopenia. No significant difference was found in in-hospital stroke outcomes and long-term outcomes for stroke and recurrent myocardial infarction between thrombocytopenic and non-thrombocytopenic groups. Conclusion Thrombocytopenia worsens ACS outcomes. Vigilance and tailored management are crucial for mitigating its impact on patient prognosis. Further research is needed for better interventions.Secondary outcomes forest plot