Undiagnosed airflow limitation in patients at cardiovascular risk.

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and cardiovascular diseases (CVD) share risk factors and impair each other's prognosis.

AIMS: To assess the prevalence of airflow limitation (AL) compatible with COPD in a population at cardiovascular risk and to identify determinants of AL.

METHODS

All consecutive patients referred to the cardiovascular prevention unit of a university hospital in 2009 were studied in a cross-sectional analysis. Patients answered questionnaires on socioeconomic status, medical history and lifestyle, and underwent extensive physical examinations, biological measures and spirometry testing. AL was defined as FEV1/FVC<0.70, without any history of asthma. Determinants of AL were assessed using logistic regression.

RESULTS

The sample comprised 493 participants (mean age 57.4±11.1 years); 60% were men, 18% were current smokers, 42% were ex-smokers and 10% of patients had a history of CVD. Ten-year risk of coronary heart disease (CHD) according to the Framingham equation was intermediate (10-20%) for 25% of patients and high (>20%) for 10%. Prevalence of AL was 5.9% (95% confidence interval [CI] 4.0-8.3%) in the whole population and 4.3% (2.6-6.6%) among subjects in primary cardiovascular prevention. AL was independently associated with CVD (adjusted odds ratio 4.18, 95% CI 1.72-10.15; P=0.002) but not with Framingham CHD risk. More than 80% of patients screened with AL had not been diagnosed previously and more than one in two patients was asymptomatic.

CONCLUSION

Patients with CVD are at increased risk of AL and thus should benefit from AL screening as they are frequently asymptomatic.