Long‑Term Implementation and Effectiveness of a Quality Improvement Intervention for Myocardial Infarction in Tanzania

Background: In Tanzania, acute myocardial infarction (AMI) is underdiagnosed, and uptake of evidence‑based care remains limited. The Multicomponent Intervention to Improve Myocardial Infarction Care in Tanzania (MIMIC) increased evidence‑based AMI care in a pilot trial conducted in a Tanzanian emergency department (ED). Whether MIMIC was sustained as implemented and its gains persisted after the pilot is unknown.

Objectives: To evaluate the long‑term fidelity, penetration, and effectiveness of MIMIC one year after the pilot trial.

Methods: We conducted a sequential cohort study in a Tanzanian ED, enrolling adults with chest pain or dyspnea during the pilot period (September 2023–August 2024) and post‑pilot period (September 2024–August 2025). Pre‑intervention data (February–August 2023) served as supplemental baseline. Outcomes included fidelity and penetration of MIMIC components and 11 AMI care metrics. Proportions were compared using Pearson’s χ² tests and odds ratios (ORs) with 95% confidence intervals (CIs).

Findings: Of 260 post‑pilot participants, 29 had AMI. Fidelity and penetration of MIMIC components were similar to pilot levels. Electrocardiogram (ECG) uptake remained high (~90% in both periods). Cardiac biomarker testing was lower post‑pilot (64.0% [n = 203, excluding stock‑out periods] vs 78.0%, OR 0.50, 95% CI 0.35–0.72; P < 0.001), coinciding with reagent stock‑outs, but exceeding pre‑intervention baseline (41.4%). Among AMI participants, treatment with aspirin, clopidogrel, heparin, and statins in the ED was comparable between pilot and post‑pilot periods. Compared with the pre‑intervention baseline, uptake of diagnostic testing and evidence‑based therapies was substantially higher, including a >5‑fold increase in 30‑day antiplatelet use (10% vs 52%; OR 9.54, 95% CI 2.49–46.46; P < 0.001).

Conclusions: One year after implementation, MIMIC demonstrated sustained fidelity, penetration, and clinical effectiveness. AMI care remained substantially improved compared with pre‑intervention baseline, suggesting that a pragmatic, workflow‑integrated intervention can achieve durable gains in AMI care in a resource‑limited ED.