Undiagnosed airflow limitation in patients at cardiovascular risk

Abstract

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.