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 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.