# Association between chronic obstructive pulmonary disease and in-hospital mortality after percutaneous coronary intervention: a retrospective cohort study in Germany

## TL;DR

This study finds that COPD patients undergoing heart procedures in Germany have higher in-hospital mortality and longer hospital stays, but mild to severe COPD is paradoxically linked to lower mortality.

## Contribution

The study reveals a paradoxical association between mild-to-severe COPD and reduced in-hospital mortality after PCI, contrasting with higher risks in very severe COPD and exacerbation/infection cases.

## Key findings

- COPD patients had higher in-hospital mortality (2.4% vs. 2.0%) and longer hospital stays compared to non-COPD patients.
- Mild to severe COPD was associated with reduced in-hospital mortality and shorter ventilation time.
- Very severe COPD, COPD with exacerbation, and infection showed higher mortality risks.

## Abstract

Chronic obstructive pulmonary disease (COPD) is one of the leading chronic diseases worldwide. However, the impact of COPD on outcome after percutaneous coronary intervention (PCI) remains unclear. In this retrospective cohort study, we analyzed the data of hospitalized patients undergoing PCI in Germany between 2015 and 2019. We compared in-hospital mortality, hospital length of stay and peri-interventional ventilation time (VT) in patients with and without COPD, including different COPD severity grades, COPD with exacerbation (COPDe) and infection (COPDi). We analyzed the data of 3,464,369 cases undergoing PCI. A total of 291,707 patients (8.4%) suffered from COPD. Patients suffering from COPD died more often (2.4% vs. 2.0%; p < 0.001), stayed longer hospitalized (5 days (2–10) vs. 3 days (1–6); p < 0.001), were more frequent (7.2% vs. 3.2%) and longer ventilated (26 h (7–88) vs. 23 h (5–92); p < 0.001). Surprisingly, COPD was associated with a 0.78-fold odds of in-hospital mortality and with reduced VT (− 1.94 h, 95% CI, − 4.34 to 0.43). Mild to severe COPD was associated with a lower risk of in-hospital mortality and reduced VT, whereas very severe COPD, COPDe and COPDi showed a higher risk of in-hospital mortality. We found a paradoxical association between mild to severe COPD and in-hospital mortality, whereas very severe COPD, COPDe and COPDi were associated with higher in-hospital mortality. Further investigations should illuminate, whether comorbidities affect these associations.