Pretreatment CHA₂DS₂-VASc-HS Score for Predicting Failed Thrombolysis in ST-Elevation Myocardial Infarction: A Cross-Sectional Diagnostic Accuracy Study in Bangladesh

BackgroundFibrinolysis remains the principal reperfusion strategy for ST-elevation myocardial infarction (STEMI) in Bangladesh and in most low-and middle-income settings, yet it fails in a substantial minority of patients, and failure is currently recognized only 90 minutes after treatment has begun.We assessed the diagnostic accuracy of the CHA 2 DS 2 -VASc-HS score, recorded before thrombolysis from the history, previous medical records, and physical examination, for failed thrombolysis. MethodologyIn this cross-sectional diagnostic accuracy study, 166 of 219 patients (75.8%) with STEMI treated with streptokinase at a tertiary cardiac center in Dhaka between February 2023 and January 2024 were enrolled by consecutive sampling and underwent CHA 2 DS 2 -VASc-HS scoring on admission, before the infusion was started.The outcome of thrombolysis was classified as successful or failed 90 minutes after the start of the infusion using a composite of clinical and electrocardiographic criteria, and all analyzed patients underwent coronary angiography within 48 hours of symptom onset.Discrimination was assessed by receiver operating characteristic analysis, an exploratory optimal cutoff by the Youden index with bootstrap internal validation, and factors independently associated with failure by multivariable logistic regression.The score was also compared with the CHADS 2 and CHA 2 DS 2 -VASc scores. ResultsThrombolysis failed in 91 patients (54.8%).The mean CHA 2 DS 2 -VASc-HS score was 4.54 ± 1.07 in the failed group and 2.52 ± 0.94 in the successful group (t = 12.98, P < 0.001).The area under the receiver operating characteristic curve was 0.933 (95% confidence interval (CI), 0.894-0.971),greater than those of the CHADS 2 score (0.845) and the CHA 2 DS 2 -VASc score (0.831) (P < 0.001 for both).A cutoff of ≥4 gave the highest Youden index (0.819), with a sensitivity of 91.2% (95% CI, 83.6%-95.5%),specificity of 90.7% (95% CI, 82.0%-95.4%),and overall accuracy of 91.0%, with negligible optimism on bootstrap validation that repeated the cutoff selection.Results were similar when ST-segment resolution alone was used as the reference standard (area under the curve, 0.948).A conservative version of the score that excluded any diabetes or hyperlipidemia classification compatible with admission laboratory values had an area under the curve of 0.863.The score correlated inversely with angiographic TIMI flow grade (ρ = -0.70,P < 0.001). ConclusionsIn this single-center cohort of South Asian patients treated with streptokinase, a pretreatment CHA 2 DS 2 -VASc-HS score of 4 or more was strongly associated with failed thrombolysis and discriminated failure with high accuracy using information recorded at presentation, although admission laboratory values may have informed two of its components in some patients.The threshold is exploratory and requires external validation.Whether it can help to prioritize limited transfer capacity is a hypothesis that requires prospective evaluation.