# Impact of Pulmonary Ventilation Dysfunction on Prognosis of Patients with Coronary Artery Disease: A Single-Center, Observational Study

## TL;DR

This study finds that lung dysfunction after heart disease is linked to worse outcomes only in smokers, not in all patients.

## Contribution

The study reveals a novel interaction between smoking and pulmonary dysfunction in predicting poor prognosis in CAD patients.

## Key findings

- Pulmonary ventilation dysfunction was not associated with MACE in the overall CAD population.
- Smoking patients with pulmonary dysfunction had a significantly higher risk of MACE.
- There was a significant interaction between smoking and pulmonary dysfunction in predicting MACE.

## Abstract

Patients with coronary artery disease (CAD) often
experience pulmonary ventilation dysfunction following their initial event.
However, there is insufficient research exploring the relationship between this
dysfunction and CAD prognosis.

To address this gap, a
retrospective observational study was conducted involving 3800 CAD patients
without prior pulmonary ventilation disease who underwent cardiopulmonary
exercise testing (CPET) during hospitalization between November 2015 and
September 2021. The primary endpoint was a composite of major adverse
cardiovascular events (MACE), such as death, myocardial infarction (MI), repeat
revascularization, and stroke. Propensity score matching (PSM) was used to
minimize selection bias between the two groups, with a subgroup analysis
stratified by smoking status.

The results showed that patients
were divided into normal (n = 2159) and abnormal (n = 1641) groups based on their
pulmonary ventilation function detected by CPET, with 1469 smokers and 2331
non-smokers. The median follow-up duration was 1237 (25–75% interquartile range
695–1596) days. The primary endpoint occurred in 390 patients (10.26%). 1472
patients in each of the two groups were enrolled in the current analysis after
PSM, respectively. However, pulmonary function was not associated with MACE
before (hazard ratio (HR) 1.20, 95% confidence interval (95% CI) 0.99–1.47;
Log-rank p = 0.069) or after PSM (HR 1.07, 95% CI 0.86–1.34;
Log-rank p = 0.545) among the entire population. Nonetheless, pulmonary
ventilation dysfunction was significantly associated with an increased risk of
MACE in smoking patients (HR 1.65, 95% CI 1.25–2.18; p
< 0.001) but
not in non-smoking patients (HR 0.81, 95% CI 0.60–1.09; p = 0.159). In
addition, there was a significant interaction between current smoking status and
pulmonary ventilation dysfunction on MACE (p for interaction < 0.001).

Pulmonary ventilation dysfunction identified through CPET
was independently associated with long-term poor prognosis in smoking patients
with CAD but not in the overall population.