Door-to-balloon performance, determinants, and clinical outcomes in low- and middle-income countries: a systematic review

Abstract Background Door-to-balloon (D2B) time is an important quality indicator in the management of ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Reperfusion delays remain common in low- and middle-income countries (LMICs). This systematic review evaluated D2B performance, factors associated with timely or delayed reperfusion and reported clinical outcomes in LMIC settings. Methods PubMed and Embase were searched from inception to 1 st August 2026. Studies reporting D2B time, related reperfusion intervals, target attainment, determinants of delay, or associated outcomes among adults with STEMI undergoing pPCI in LMICs were included. Risk of bias was assessed using the Newcastle-Ottawa Scale. Because of substantial clinical and methodological heterogeneity, findings were synthesised narratively. Results Twenty-four studies collectively enrolling 29,319 patients with STEMI across 11 LMIC settings were included. Conventional study-level D2B estimates ranged from 34 to 169 min. Among 17 studies with conventional D2B estimates that could be classified relative to the 90 min benchmark, 12 reported values consistently within 90 min and five reported values exceeding 90 min; three additional studies reported subgroup or intervention-period estimates spanning the threshold. Reported facilitators included continuous pPCI availability, single-call catheterisation-laboratory activation, simulation-based team training, direct emergency-department-to-catheterisation-laboratory transfer, regular audit and feedback, ambulance presentation, and organised referral networks. Reported barriers included delayed presentation, interhospital transfer, limited emergency medical service utilisation, reduced out-of-hours capacity, financial or administrative processes, treatment-consent delays, and movement or transport restrictions. Crude in-hospital mortality ranged from 1.0% to 24.3%. Several studies reported associations between longer reperfusion intervals and mortality, major adverse cardiovascular events, or myocardial injury. Conclusions D2B performance varied substantially across LMIC settings. Protocolised activation, continuous pPCI availability, multidisciplinary training, and coordinated referral pathways were reported alongside shorter treatment intervals, whereas prehospital, transfer, financial, and administrative delays remained important barriers. Quality-improvement programmes should address total ischaemic time rather than D2B time alone.