Risk factors for inspiratory muscle weakness in coronary heart disease.

Background: Patients with coronary heart disease (CHD) are susceptible to lung function problems caused by respiratory muscle weakness. Many CHD patients show complications of respiratory muscle weakness, but the risk factors remain unclear.

Objective: To explore the risk factors for inspiratory muscle weakness in CHD.

Methods: This study enrolled 249 patients with CHD who underwent maximal inspiratory pressure (MIP) measurement between April 2021 and March 2022.According to the percentage of MIP (MIP/Predicted normal value [PNV]), patients were divided into the inspiratory muscle weakness (IMW) (n = 149) (MIP/PNV<70%) and control groups (n = 100) (MIP/PNV≥70༅). Clinical information and MIP of the two groups were collected and analyzed.

Results: The incidence of IMW was 59.8% (n = 149). Age (P < 0.001); history of heart failure (P < 0.001), hypertension (P = 0.04), and peripheral artery disease (PAD) (P = 0.001); left ventricular end-systolic dimension (P = 0.035); presence of segmental motion abnormality of the ventricular wall (P = 0.030); and high density lipoprotein cholesterol (P = 0.001) and N-terminal brain natriuretic peptide (NT-proBNP) levels (P < 0.001) in the IMW group were significantly higher than those in the control group. The proportion of anatomic complete revascularization (P = 0.009), left ventricular ejection fraction (P = 0.010), and alanine transaminase (P = 0.014) and triglycerides levels (P = 0.014) in the IMW group were significantly lower than those in the control group. Logistic regression analysis showed that anatomic complete revascularization (OR=0.350, 95%CI 0.157-0.781) and NT-proBNP level (OR=1.002, 95%CI 1.000-1.004) were independent risk factors for IMW.

Conclusion: The independent risk factors for decreased IMW in patients with CAD were anatomic incomplete revascularization and NT-proBNP level.