Poor physical performance raises red flag for CV hospitalization in COPD patients

Patients with chronic obstructive pulmonary disorder (COPD) who perform poorly on the 6-min walk test (6MWT) are at increased risk of cardiovascular (CV)-related hospitalizations, a study has found.

The study involved 714 individuals (median age, 67 years; 61 percent male) with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II–IV COPD. They smoked at least 10 pack years and were clinically stable for >4 weeks.

All patients underwent baseline assessments including aortic pulse wave velocity (aPWV), carotid intima–media thickness (CIMT), C-reactive protein (CRP), fibrinogen, spirometry, as well as Body mass index, airflow Obstruction, Dyspnoea and Exercise capacity (BODE) Index, 6MWT, and 4-min gait speed (4MGS) test.

Over a median follow-up of 4.6 years, 192 patients (27 percent) had a first event of CV hospitalization (peripheral arterial disease, diseases of arteries, arterioles and capillaries, angina, unstable angina, coronary heart disease, acute myocardial infarction, cerebral infarction, or stroke, among others). There were six CV deaths documented without any preceding CV episode. The overall CV incidence rate was 6.7 per 100 person-years.

Conventional CV risk factors had a C-statistic of 0.689 (95 percent confidence interval [CI], 0.688–0.691) in predicting CV outcomes in COPD. Both aPWV and CIMT had no association with fatal/nonfatal CV-related hospitalization, and neither did they improve model prediction.

On the other hand, CRP, fibrinogen, GOLD stage, BODE Index, 4MGS, and 6MWT were associated with the outcome, independently of conventional risk factors (p<0.05 for all). However, only 6MWT improved the predictive value of the conventional CV model (C, 0.727, 95 percent CI, 0.726–0.728).

These findings suggest that physical performance assessment may enhance CV risk evaluation in COPD patients.