Do pulmonary function tests improve risk stratification before cardiothoracic surgery? | JoVE Visualize

Area of Science:

Cardiothoracic Surgery
Pulmonary Medicine
Health Outcomes Research

Background:

The Society of Thoracic Surgeons (STS) risk model is widely used for predicting outcomes after cardiothoracic (CT) surgery.
Pulmonary function tests (PFTs) and chronic obstructive pulmonary disease (COPD) classifications are potential factors that may refine risk prediction.
Assessing the added value of PFTs and COPD classifications to the STS model is crucial for optimizing patient care.

Purpose of the Study:

To evaluate the incremental predictive value of PFTs and various COPD classifications when added to the STS risk model.
To determine if these additions improve the prediction of respiratory failure, prolonged postoperative stay, and 30-day mortality after CT surgery.
To assess the clinical utility of routine preoperative PFTs in the context of the STS score.

Main Methods:

A cohort of patients undergoing nonemergency cardiac surgery with preoperative PFTs was analyzed.
The STS risk model (version 2.73) was used to estimate risks for respiratory failure, prolonged postoperative stay (PPLS), and 30-day mortality.
Receiver operating characteristic (ROC) curves were generated to compare the area under the curve (AUC) of the STS score alone versus the STS score with PFT parameters and COPD classifications.

Main Results:

The STS score demonstrated moderate predictive ability for respiratory failure (AUC=0.65), PPLS (AUC=0.67), and 30-day mortality (AUC=0.74).
Adding individual PFT parameters or different COPD classifications did not significantly enhance the predictive accuracy of the STS model for any of the adverse outcomes.
No improvement in AUC was observed when PFTs or COPD classifications were incorporated into the STS score.

Conclusions:

The addition of PFT parameters or COPD classifications to the STS risk model does not improve its discriminative ability for predicting outcomes after CT surgery.
Routine preoperative PFTs may have limited value in patients undergoing CT surgery if the STS score is already calculated.
Current clinical definitions of lung disease used in the STS model appear sufficient for risk stratification in this population.