Association of socioeconomic status with streptokinase reperfusion failure and in-hospital outcomes in STEMI: evidence from conflict-affected Yemen

Abstract Background Socioeconomic status (SES) influences cardiovascular outcomes, but the association between SES and thrombolytic efficacy in conflict-affected, resource-limited settings—where streptokinase (SK) remains the primary reperfusion strategy—remains unknown. We examined the association between SES, SK reperfusion failure, and acute in-hospital outcomes among STEMI patients in Yemen. Methods This prospective observational study enrolled 216 STEMI patients receiving SK (2024–2025) at a tertiary hospital in Sana’a, Yemen. SES was assessed using a context-adapted composite score. Reperfusion failure was defined as failure to achieve ≥ 50% resolution of ST-segment elevation at 90 min after thrombolysis. Multivariable logistic regression and E‑values assessed robustness to unmeasured confounding. Results Low-SES patients had longer symptom-to-door times (360 vs. 240 min; P = 0.004) and total ischemic times (434 vs. 330 min; P = 0.004). Successful reperfusion occurred in 27.0% of low-SES, 65.8% of intermediate-SES, and 80.6% of high-SES patients ( P < 0.001). In-hospital mortality (6.8% vs. 0.9% vs. 0%; P = 0.019) and major adverse cardiovascular events (MACE) (18.9% vs. 9.9% vs. 6.5%; P = 0.042) showed similar gradients. After full adjustment, low SES remained independently associated with markedly higher odds of reperfusion failure (OR: 16.19; 95% CI: 4.92–53.29; P < 0.001; E-value = 31.88). Post-thrombolysis PCI rates were similar across SES groups. Conclusions In a conflict-affected setting, low-SES is independently associated with a higher risk of SK reperfusion failure, prolonged prehospital delays, and adverse in-hospital outcomes, including mortality and MACE. Context-appropriate interventions—such as subsidized emergency transport and pharmaco-invasive networks—are essential to mitigate prehospital delays and promote equitable STEMI care.