Relevance of the GOLD 2017 recommendations in habitual clinical practice

The new GOLD document (Global Initiative for Chronic Obstructive Lung Disease) 2017 [ ] recommends guiding the treatment of chronic obstructive pulmonary disease (COPD) predominantly based on the degree of dyspnea and the occurrence of exacerbations, excluding FEV₁ from the decision-making process. Although we are fully aware that this document is oriented to the management of COPD and not to an individual patient with COPD, the fact of excluding said parameter from the therapeutic algorithm further widens the gap between the purpose of the GOLD guidelines and the reality we have to face daily. Other consensus or standard clinical practice documents on diseases such as hypertension or diabetes mellitus take into account objective and perfectly measurable parameters, such as blood pressure or glycosylated hemoglobin, for decision making. By “rejecting” the only objective parameter in our specialty, GOLD recommendations imply decisions based on frequently subjective measurements. The definition of exacerbations of COPD is currently non-specific, i.e. a persistent deterioration beyond the usual daily variability and compared to the baseline clinical situation of the patient that requires therapeutic adjustment [ ]. Furthermore, in many cases the trigger is not easily recognizable, at least when regarding the profile of the patients who come to our consultations. A number of studies have shown that between 60% and 90% of the patients with COPD have some associated comorbidity, with an average of four chronic diseases per patient [ ]. Cerebrovascular accidents, cardiovascular diseases, lung cancer, muscle involvement, and anxiety or depression are among the most prevalent comorbidities [ ], which will affect to a greater or lesser extent the patients' symptomatology. Dyspnea, the principal limiting symptom of COPD, encompasses both qualitative and quantitative aspects, thus generating an important heterogeneity in symptom expression in this disease [ ]. Frei et al. [ ] observed that the occurrence of depression, anxiety, cerebrovascular disease, peripheral arterial disease, heart failure, and ischemic heart disease interfered with the health status of COPD patients and exhibited a good correlation with each of the components of the CRQ questionnaire. Consistent with this report, Kahnert et al. [ ] recently described how mental illness and ischemic heart disease were related to patients with more symptomatic COPD, where groups B and D of the GOLD 2017 classification and groups A and C resulted in an OR of 1.58 (95% CI 1.253–2.007, p ≤ 0.001) and an OR of 1.90 (95% CI 1.452–2.493, p ≤ 0.001), respectively, while heart failure (OR 1.852, 95% CI 1.205–2.845) and sleep apnea (OR 1.485, 95% CI 1.079–2.044) were related to subjects at a higher risk of exacerbation (groups C and D vs A and B, according to GOLD 2017). Therefore, in habitual clinical practice, the symptoms of our patients cannot be attributed exclusively to COPD, especially if we lack objective data to support it. Nonetheless, consensus documents, such as GOLD 2017, base their recommendations on data from clinical trials where a large proportion of COPD patients with relevant comorbidities are excluded. Trials such as FLAME [ ], with a prevalence of cardiovascular disease of less than 10%, differ from the outcomes obtained in studies conducted in routine clinical practice, such as CONSISTE [ ], where up to 12.5% of the COPD patients had ischemic heart disease, 16% cardiac arrhythmia, 24.5% heart failure, and 35% were obese.