Does Reduced Forced Expiratory Volume in One Second have an Influence on Early Postoperative Outcomes after Minimally Invasive Mitral Valve Surgery?

Background: Minimally invasive mitral valve surgery is the gold standard surgical treatment for mitral valve pathologies. However, it is technically challenging and demands longer surgery time and single lung ventilation. This might impact the outcome of patients with impaired lung function. We therefore investigated the early postoperative outcome of patients with diminished forced expiratory volume in one second.

Methods: In a retrospective cohort study, we compared patients with a forced expiratory volume in one second (FEV1) of <80% and ≥80% who underwent minimally invasive mitral valve surgery. The primary endpoint was 30-day mortality. Secondary endpoints were overall intubation time, length of stay on intensive care unit as well as incidences of postoperative respiratory insufficiency and pneumothorax.

Results: Data were collected from January 2011 until December 2022. A study group (FEV1 ≤80%, n = 297) and a control group (FEV1 >80%, n = 443) were formed. Patients from the study group had a lower incidence of mitral valve insufficiency (82% vs. 90%; p < 0.001) and a higher rate of mitral valve stenosis (9% vs. 4%; p = 0.002). The repair rate was lower in the study group (55% vs. 71%; p < 0.001). No difference was seen in surgery time (208 vs. 207 minutes; p = 0.74) and time on cardiopulmonary bypass (137 vs. 138 minutes; p = 0.72). Patients of the study group showed a slightly higher incidence of postoperative wound healing disorder (10% vs. 5%; p = 0.016). No difference was seen in postoperative respiratory insufficiency (8% vs. 5%; p = 0.068), arrhythmia (14% vs. 10%; p = 0.11), pneumothorax (7% vs. 5%; p = 0.2), right ventricular failure (3% vs. 4%; p = 0.84) and bleeding (10% vs. 6%; p = 0.085). Patients from the study group had a longer intubation time (12 vs. 10 hours, p < 0.001) and time on catecholamines (20 vs. 16 hours; p < 0.001). No difference was seen in the 30-day mortality (2% vs. 2%; p = 1).

Conclusion: Despite a slightly longer intubation time and time on ICU, reduced FEV1 does not affect the early postoperative outcome of patients undergoing minimally invasive mitral valve surgery.