Lung function and cardiovascular disease: A link.

The relationship between lung and heart diseases has long been recognized, with necropsy studies demonstrating silent myocardial infarctions or coronary artery calcification in patients with advanced emphysema as the death cause. Improvements in non-invasive techniques and epidemiologic approaches established that lung and cardiovascular diseases frequently coexist in mid and late life. Even among those without diagnosed lung disease, lower than expected forced vital capacity, forced expiratory volume in 1 s, and their ratio each portend greater risk of developing cardiovascular risk factors including hypertension, obesity, and metabolic syndrome, and for incident cardiovascular diseases including left heart failure, atrial fibrillation and stroke. Greater longitudinal declines in these spirometric measures are further associated with cardiovascular morbidity and mortality. While obstructive ventilatory patterns are more common, restrictive ventilatory patterns seem to demonstrate an independent and more robust association with cardiovascular diseases such as heart failure. These subclinical alterations in pulmonary function also relate to subclinical abnormalities of cardiac structure and function. Although the biologic pathways linking pulmonary and cardiovascular dysfunction are not clear, chronic systemic inflammation appears to be one important underlying pathophysiologic link. Despite the growing evidence of lung dysfunction as a cardiovascular risk factor, spirometric evaluation is still underutilized in clinical practice, particularly among cardiac patients, and optimal therapeutic and preventive strategies are still unclear. In this review, we address the current knowledge and controversies regarding the links between lung function and cardiovascular disease.