Cardiovascular diseases are common among patients with moderate-to-very-severe COPD. Worsening respiratory functions may have a negative impact on the heart and can be used to monitor the cardiac function in these patients. In addition to the standard cardiac risk factors, FVC, hypoxia, and BNP may add predictive information about cardiac functions in COPD patients. This evidence concerns the gene NPPB and chronic obstructive pulmonary disease.