Evaluation of the Causes of Door-to-Balloon Time Delays in Patients with ST-Elevation Myocardial Infarction at Tehran Heart Center

BACKGROUND: Coronary artery disease (CAD) is the leading cause of cardiovascular death globally, and the most severe form of CAD, ST-elevation myocardial infarction (STEMI), needs immediate treatment. This study aimed to report patient characteristics and the causes of door–to–balloon time (D2BT) delays in STEMI patients admitted to Tehran Heart Center with a D2BT exceeding 90 minutes. METHODS: This cross-sectional study was conducted at Tehran Heart Center, Iran, from March 20th, 2020, through March 20th, 2022. Variables consisted of age, sex, diabetes mellitus, hypertension, dyslipidemia, smoking, opium, family history of CAD, in-hospital mortality, primary percutaneous coronary intervention results, culprit vessels, causes of delays, the ejection fraction, triglycerides, and low and high-density lipoprotein levels. RESULTS: The study population was composed of 363 patients (272 males [74.9]) at a mean (SD) age of 60±11.47 years. The leading causes of D2BT delays were the catheterization lab used in 95 patients (26.2) and misdiagnosis in 90 (24.8). Other causes were ST-elevation less than 2 mm in electrocardiograms in 50 patients (13.8) and referral from other hospitals in 40 (11.0). CONCLUSION: The catheterization lab in use and misdiagnosis were the leading causes of D2BT delays. We recommend that high-volume centers allocate an additional catheterization lab with an on-call cardiologist. Improved resident training and supervision in hospitals with many residents are also necessary.