Invasive mechanical ventilation in acute coronary syndromes in the era of percutaneous coronary intervention.

Background: Percutaneous coronary intervention (PCI) improves prognosis in patients with acute coronary syndromes (ACS) reducing ischaemic complications and the development of heart failure, thus potentially changing invasive mechanical ventilation (IMV) requirements. Little information exists about patients with ACS requiring IMV in the current era. We aimed to analyze IMV requirements and characteristics of ACS patients treated under current recommendations (including a high rate of PCI).
Methods: Baseline characteristics, indications for IMV, management and in-hospital and mid-term clinical course were analyzed prospectively in a consecutive series of patients with ACS admitted to a tertiary care hospital.
Results: We included 1821 patients, of which 106 (5.8%) required IMV. Mean follow-up was 347 days. PCI was performed in 84% of cases. Patients with IMV had more comorbidities, worse left ventricular function and more unstable hemodynamic parameters on admission. In-hospital mortality in patients requiring IMV was 29%. These patients also had higher mid-term mortality (hazard ratio (HR) 6.58; 95% confidence interval (CI) 4.49-9.64; p 0.001). The most common indication for IMV was cardiopulmonary arrest (CA) (65; 61%), followed by pulmonary oedema (27; 26%) and shock (14; 13.2%). Patients with CA were younger, with better hemodynamic parameters at admission, more favourable coronary anatomy and higher rates of PCI. There were no significant differences in overall mortality between the three groups. The main cause of death in CA patients was persistent vegetative state.
Conclusions: Mortality in patients with ACS requiring IMV remained high despite a high rate of PCI. Baseline characteristics, management and clinical course were different according to the reason for IMV. The most common cause for IMV requirement was CA.