A systematic review and meta-analysis of impact of baseline thrombocytopenia on cardiovascular outcomes and mortality in patients undergoing percutaneous coronary intervention

Background: Thrombocytopenia (TP) is associated with higher incidence of bleeding in the setting of percutaneous coronary intervention (PCI) leading to increased morbidity and mortality. Herein, we report a meta-analysis evaluating the effects of baseline thrombocytopenia (bTP) on cardiovascular outcomes in patients undergoing PCI. Methods: Literature search was performed using PubMed, Embase, Cochrane library and clinicaltrials.gov from inception till October 2019. Patients were divided into two groups: Patients with (a) no Thrombocytopenia (nTP) (b) bTP before PCI. Primary endpoints were in-hospital, and all-cause mortality rates at the longest follow-up. The main summary estimate was random effects risk ratio (RR) with 95% confidence intervals (CIs). Results: A total of 6,51,543 patients from 10 retrospective studies were included. There was increased in-hospital all-cause mortality (RR 2.58 [1.7–3.8], p <.001) and bleeding (RR 2.37 [1.41–3.98], p <.005), in the bTP group compared to the nTP group. There was no difference for in-hopsital major adverse cardiovascular outcomes (MACE) (RR 1.38 [0.94–2.0], p <.10), post-PCI MI (RR 1.17 [0.9–1.5], p =.19) and TVR (RR 1.65 [0.8–3.6], p =.21), respectively. Outcomes at longest follow-up showed increased incidence of all-cause mortality (RR 1.86 [1.2–2.9], p <.006) and bleeding (RR 1.72 [1.1–2.9], p =.04) in bTP group, while there was no significant difference for post-PCI MI (RR 1.07 [0.91–1.3], p =.42), MACE (RR 1.86 [0.69–1.8], p =.68) and TVR (RR 1.1 [0.9–1.2], p =.93) between both groups. Conclusions: bTP in patients undergoing PCI is associated with increased mortality and predicts risk of bleeding.