Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 0 0 2025 11 15 1342 1342 Naghmeh Ahmadi Anesthesia and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. & Department of Anesthesia and Critical Care, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Shima Karbasi Anesthesia and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Nasim Rabani Anesthesia and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Zahra Sardarpour Anesthesia and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Marjan Mansourian Department of Epidemiology and Biostatistics, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran. Nazanin Seddighi Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran. Mahmoud Saghaei Anesthesia and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. & Department of Anesthesia and Critical Care, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2025 07 13 2025 09 01 Background: COVID-19 patients requiring invasive mechanical ventilation represent the most severe cases with high mortality rates. This study aimed to analyze survival outcomes and identify prognostic factors in a cohort of invasive mechanically ventilated COVID-19 patients in Iran. Methods: In this retrospective cohort study, we analyzed 639 adult COVID-19 patients who underwent invasive mechanical ventilation at Al-Zahra Hospital's ICUs in Isfahan. Survival analysis and Cox regression models were used to identify factors associated with mortality. Results: Among 639 mechanically ventilated patients, mortality was 87.9%. The mean age was 63.01±16.4 years. 59.8% of participants were male. Hypertension (42.6%), diabetes (33.8%), and cardiovascular disease (25.0%) were the most prevalent comorbidities. The overall median survival time was 35 days. Cox regression analysis identified significant mortality predictors, including male sex (HR=3.489, 95% CI: 1.150-10.585), age (HR=1.064, 95% CI: 1.024-1.106), cardiovascular disease (HR=1.445, 95% CI: 1.096-1.905), higher APACHE IV score (HR=1.028, 95% CI: 1.005-1.051), and delayed mechanical ventilation after disease onset (HR=1.111, 95% CI: 1.031-1.196). Conclusion: COVID-19 patients with invasive mechanical ventilation demonstrated high mortality rates. Older age, male sex, cardiovascular disease, higher APACHE IV score, and delayed mechanical ventilation after symptom onset were significant predictors of mortality. These findings highlight the importance of timely intervention in high-risk patients and may help optimize resource allocation during future pandemic waves. https://aacc.tums.ac.ir/index.php/aacc/article/view/1342