We read with interest the article by Crespo-Leiro et al. on treatment adherence in outpatients with heart failure (HF). The article highlighted at least 2 important points: the high standard of prescribing in this area by cardiologists and, most notably, the good treatment adherence in the patients studied,1 with figures much better than those reported in previous publications.2
Our comments and objections relate to the patients’ age, a detail that was not mentioned in the discussion, even in the section on limitations. The mean age of the patients was 65 years, and no patients were older than 73 years. This was surprising and seriously calls into question the representativeness of the whole study.
The age at which HF presents is increasingly older. The incidence and prevalence of the syndrome double every decade from the age of 45 years.3 Over the last 40 years, the age at first episode has increased by some 15 years, and 70% of patients admitted for heart failure are older than 70 years.4,5
Epidemiological data are in line with the literature on the subject, such as the successive NHANES reports and the PRICE study in Spain.4 In a study of close to 6000 patients carried out in Spanish emergency departments, the mean patient age was 79.4 years, and only 8.5% were younger than 65 years.5 The Rotterdam study reported a HF prevalence of 0.9% in 55 to 64-year-olds, and 17.4% in those older than 85 years; the incidence was 1.4/1000 in 55 to 59-year-olds and 47.4/1000 in those older than 90 years.6 The Swedish HF hospital registry is very significant, due to the number of patients included: it spanned 12 years and included 156 919 patients with a primary discharge diagnosis of HF (295 425 if secondary diagnoses are included); only 8% of the men and 5% of the women were younger than 65 years.7
An explanation is required. One, very weak, explanation is that the authors concentrated on outpatients; a more convincing explanation is that the study was carried out only by cardiologists in cardiology clinics, when in reality HF is managed by many other specialties (such as general practice, health care for the elderly, and general medicine). One registry, spanning an entire year of data from Hospital Clínico San Carlos, Madrid, showed that, of almost 1000 diagnoses of HF appearing in discharge reports that year, fewer than 200 were from the cardiology department. The mean age of those cardiology patients was 70.9 years, while patients from general medicine had a mean age of 80 years, and those from health care for the elderly, 88 years.8
Although some progress has been made, there is more ground to be covered by the official scientific societies that represent cardiology in Europe and in Spain. Complex and highly prevalent syndromes such as HF must be studied from a broader perspective and should not be limited to cardiologists in order to eliminate significant biases such as that found in the study prompting these comments.