The research, led by Tasneem Al-Namshah and colleagues at Sana’a University with collaborators at Al-Razi University, enrolled 216 patients diagnosed with STEMI who received streptokinase at a tertiary hospital in Sana’a between 2024 and 2025. Yemen, devastated by years of armed conflict, offers a rare and sobering window into how cardiovascular care functions when resources are scarce and infrastructure is shattered. The team assessed each patient’s socioeconomic status using a composite score adapted to the local context, capturing the realities of income, education, and living conditions in a country where conventional measures of wealth may not translate cleanly. Patients were then followed through their hospital stay to track whether the drug succeeded in reopening the infarct-related artery and how they fared clinically.

The technical definition of success was rigorous. Reperfusion failure was defined as failure to achieve at least 50 percent resolution of the elevated ST segments on the electrocardiogram at 90 minutes after thrombolysis, a standard surrogate indicating that the occluded coronary artery has not been adequately reopened and that myocardial tissue remains starved of blood. By this measure, the socioeconomic gradient was dramatic. Successful reperfusion was achieved in only 27.0 percent of patients in the low socioeconomic group, compared with 65.8 percent of those of intermediate status and 80.6 percent of high-status patients, a difference that was highly statistically significant. In other words, the poorest patients failed thrombolysis nearly three times as often as the wealthiest, and more than twice as often as those in the middle tier.

Part of the explanation lies in time. The study documented that low-socioeconomic-status patients arrived at the hospital far later after symptom onset, with a median symptom-to-door time of 360 minutes compared with 240 minutes for their higher-status counterparts, a difference that was statistically significant. Total ischemic times, which encompass the entire duration from the first symptom to reperfusion, followed the same pattern at 434 versus 330 minutes. This matters because thrombolytic efficacy is strongly time-dependent: the longer a clot has matured and the more myocardium has been jeopardized, the less likely fibrinolysis is to achieve complete and sustained reperfusion. Six hours of delay, as seen in the poorest group, pushes patients well beyond the window in which streptokinase performs optimally.

The downstream clinical consequences were equally stark. In-hospital mortality climbed along the socioeconomic gradient, from zero percent among high-status patients to 0.9 percent in the intermediate group and 6.8 percent among the poorest. Major adverse cardiovascular events, a composite endpoint typically encompassing death, reinfarction, and other serious cardiac complications, affected 18.9 percent of low-status patients versus 9.9 percent of intermediate and 6.5 percent of high-status patients. Both gradients were statistically significant, painting a coherent picture in which poverty was associated not only with failed reperfusion but with worse survival and more complications during the same hospital admission.

Crucially, the investigators did not stop at simple associations. They employed multivariable logistic regression, adjusting for potential confounders, and found that low socioeconomic status remained independently associated with markedly higher odds of reperfusion failure, with an odds ratio of 16.19 and a 95 percent confidence interval of 4.92 to 53.29. To probe the robustness of this finding against unmeasured confounding, the team calculated an E-value, a quantitative sensitivity metric indicating how strong an unmeasured factor would need to be to explain away the observed association. The E-value of 31.88 is extraordinarily high, suggesting that no plausible unmeasured variable, short of an implausibly powerful one, could plausibly account for the entire effect. This analytical rigor strengthens the argument that the socioeconomic gradient reflects a genuine causal pathway rather than statistical artifact.

One particularly informative finding concerns what did not differ. Rates of post-thrombolysis percutaneous coronary intervention, the rescue or adjunctive procedure performed after clot-dissolving drugs, were similar across socioeconomic groups. This suggests that the disparity was not driven by unequal access to mechanical revascularization once patients were inside the hospital. Instead, the damage appears to be done before patients ever reach the hospital doors, in the hours lost to delayed recognition of symptoms, lack of transportation, financial barriers to seeking care, and the logistical chaos of a conflict zone. The authors argue that context-appropriate interventions, including subsidized emergency transport and pharmaco-invasive networks that link thrombolysis in peripheral settings to timely angiography, are essential to mitigate these prehospital delays and promote equitable STEMI care.

The Yemeni findings resonate with a broader literature linking socioeconomic position to cardiovascular outcomes, but they sharpen the picture in an important way. Most prior studies have examined disparities in access to advanced procedures or in long-term outcomes shaped by secondary prevention and rehabilitation. This study isolates a more fundamental inequity: the biological efficacy of the initial reperfusion therapy itself. If the clot-dissolving drug fails more often in poor patients largely because they arrive later, then the intervention point is prehospital, encompassing public awareness of heart attack symptoms, affordable and rapid transport, and streamlined triage. In a conflict-affected setting where ambulances are scarce, fuel is expensive, and roads are dangerous, each of these steps becomes a formidable barrier for families with the fewest resources.

The study does carry limitations inherent to its design and setting. As a single-center prospective observational study of 216 patients, its findings require replication in other conflict-affected and resource-limited environments before broad generalization. The composite socioeconomic score, while context-adapted, cannot capture every dimension of disadvantage, and observational designs can never fully exclude residual confounding, however reassuring the E-value may be. Streptokinase itself is an older thrombolytic with known limitations, including antigenicity and a relatively high failure rate even under ideal circumstances, which may have amplified the observed gradients. Nevertheless, the internal consistency of the data, spanning delay times, reperfusion success, mortality, and composite adverse events, lends the conclusions considerable weight.

For global health, the message is uncomfortable but clear. Cardiovascular disease is no longer a affliction confined to wealthy nations, and the tools available to poorer countries must be made to work for everyone within them. Streptokinase costs only a few dollars per dose, yet its effectiveness in Yemen appears to be rationed by circumstance as much as by biology. The authors’ call for subsidized emergency transport and pharmaco-invasive networks represents a pragmatic, achievable agenda: rather than waiting for catheterization laboratories that may take decades to build, health systems can invest in the unglamorous logistics of getting patients through the door faster and connecting fibrinolysis to follow-up angiography. In a world where conflict and poverty increasingly shape disease outcomes, this study demonstrates that the fight for health equity begins not in the operating theater but on the road to the hospital.

Subject of Research: Socioeconomic disparities in thrombolytic reperfusion success and outcomes after ST-elevation myocardial infarction in conflict-affected Yemen

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

Article References: Al-Namshah, T., Al-Kebsi, M., Alradi, A., Al-Habeet, A., Al-Motarreb, A., Al-Wather, N., Alodhari, R., & Al-Jalal, A. (2026). Association of socioeconomic status with streptokinase reperfusion failure and in-hospital outcomes in STEMI: evidence from conflict-affected Yemen. International Journal for Equity in Health. https://doi.org/10.1186/s12939-026-03047-y

Image Credits: AI Generated

DOI: 10.1186/s12939-026-03047-y

Keywords: socioeconomic status, STEMI, streptokinase, reperfusion failure, Yemen, thrombolysis, health equity, conflict-affected settings, in-hospital mortality, MACE, prehospital delay, cardiovascular outcomes

Researchers analyzing data from 27,510 hypertensive participants in the UK Biobank Pharma Proteomics Project have developed separate protein-based risk scores for men and women that substantially improve the prediction of major adverse cardiovascular events, or MACE, over a ten-year horizon. The work, published in Biology of Sex Differences, harnessed large-scale plasma proteomic profiling to capture biological information that conventional clinical risk models simply do not see.

The team, led by researchers at Jilin University in China, applied a sex-stratified machine learning strategy known as Least Absolute Shrinkage and Selection Operator, or LASSO, regression to sift through thousands of circulating proteins. This technique penalizes complexity and selects only the most informative features, producing lean statistical models built from the proteins most strongly associated with future cardiovascular events. The result was a panel of 28 priority proteins for men and 23 for women, with only five proteins shared between the sexes: MMP12, NT-proBNP, NEFL, BCAN, and ADAMTS13.

That limited overlap is one of the most intriguing findings of the study. MMP12 is a matrix metalloproteinase involved in tissue remodeling and inflammation, while NT-proBNP is a well-established marker of cardiac strain. NEFL, a neurofilament light chain protein, signals neuronal injury, and ADAMTS13 is an enzyme that regulates blood clotting by cleaving von Willebrand factor. BCAN, brevican, is less familiar in cardiovascular circles, being primarily associated with the extracellular matrix of the brain. The fact that these five proteins anchor both models while the remaining two dozen or so differ suggests that the molecular pathways driving cardiovascular risk in hypertensive men and women are only partially shared.

The predictive power of the scores was considerable. In the validation set, participants in the highest protein risk group faced dramatically elevated odds of a major cardiovascular event compared with those in the lowest group. For men, the adjusted hazard ratio was 2.68, with a 95 percent confidence interval of 1.97 to 3.64. For women, it was even higher at 3.12, with a confidence interval of 2.20 to 4.43. In practical terms, a hypertensive person whose blood protein profile placed them in the top risk tier was roughly three times as likely to suffer a heart attack, stroke, or cardiovascular death within a decade as someone in the bottom tier.

Crucially, the protein scores added value on top of SCORE2, the standard European clinical tool for estimating ten-year cardiovascular risk. When the protein scores were integrated into the SCORE2 framework, the C-statistic, a measure of how well a model discriminates between people who do and do not experience events, rose from 0.627 to 0.667 for men and from 0.657 to 0.695 for women. Category-based net reclassification improvement, which quantifies how many people are correctly shifted into more accurate risk categories, reached 22.4 percent for men and 14.0 percent for women. These are meaningful gains in a field where incremental improvements in prediction can translate into lives saved through earlier intervention.

Recognizing that a 28-protein panel may be impractical for routine clinical testing, the researchers also constructed simplified scores using only the ten most heavily weighted proteins for each sex. In the simplified models, just two proteins overlapped between men and women, underscoring how divergent the sex-specific signatures are. Remarkably, these pared-down scores maintained predictive performance comparable to the full models, suggesting that a compact blood test measuring a handful of proteins could one day flag high-risk hypertensive patients who appear deceptively healthy by conventional measures.

Pathway enrichment analyses of the male and female protein panels revealed that the biological processes represented in the two models partially overlap, while others receive different relative emphasis. The authors are careful to note that these findings support sex-stratified prediction strategies rather than proving fundamentally distinct disease mechanisms between the sexes. The differences in protein selection may reflect genuine biological divergence, but they may also stem from differences in how proteins correlate with risk in each population. Either way, the study adds to mounting evidence that cardiovascular medicine, which has historically been built on data from men, should routinely stratify its models by sex.

The clinical implications are tantalizing. Hypertension is among the most prevalent and serious cardiovascular risk factors worldwide, and current risk prediction tools rely almost exclusively on conventional clinical variables such as age, cholesterol, smoking status, and systolic blood pressure. These tools cannot see the inflammatory, thrombotic, and cardiac stress processes that proteins like MMP12, ADAMTS13, and NT-proBNP reveal. A proteomic layer of risk assessment could identify which hypertensive patients need more aggressive therapy, closer monitoring, or novel interventions long before symptoms appear.

Important caveats remain. The scores were developed and validated within the UK Biobank, a cohort that is not fully representative of global populations, and the researchers emphasize that external validation in independent and more diverse cohorts is required before the scores can be considered clinically transportable. The study also relied on internal validation, and the modest though significant gains in discrimination must be weighed against the cost and complexity of proteomic testing. Still, as large-scale protein measurement becomes faster and cheaper, the prospect of a routine blood panel that reads the molecular weather forecast for the cardiovascular system is moving closer to reality. For the millions of people with hypertension whose risk is invisible to today’s models, that forecast could not come soon enough.

Subject of Research: Sex-stratified proteomic risk scores for predicting major adverse cardiovascular events in hypertensive patients

Article Title: Sex-specific proteomic risk scores reveal distinct cardiovascular risk profiles and improve prediction of major adverse cardiovascular events in hypertension

Article References: Ding, J., Li, J., Xu, W., Zhang, W., Gao, Y., & Cheng, L. (2026). Sex-specific proteomic risk scores reveal distinct cardiovascular risk profiles and improve prediction of major adverse cardiovascular events in hypertension. Biology of Sex Differences. https://doi.org/10.1186/s13293-026-00984-9

Image Credits: AI Generated

DOI: 10.1186/s13293-026-00984-9

Keywords: hypertension, proteomics, cardiovascular risk, UK Biobank, SCORE2, biomarkers, sex differences, LASSO regression, MACE, risk prediction, NT-proBNP, precision medicine