The Epidemiology of Isolated (Independent) Heart Failure Is Still Looking for Authors?

The concepts of “isolated” or “idiopathic” heat failure (CHF/HF) and more recently of “non-dilated cardiomyopathy” lack a clear description of the specific characteristics that help condense the disease into a nomenclature-based list applicable to population studies. This ensued in the absence of primary preventive investigations of CHF/HF. Moreover, in the large spectrum of cardiovascular diseases (CVD), the conditions attributable to coronary heart diseases (CHD) from those related to CHF/HF or other causes are not in general disentangled. We review here current results prompting the operational idea to index heart diseases of uncertain etiology (HDUEs) from a population-based perspective in several contributions, where CHF/HF represented 50% of HDUEs, approximately 10% of all CVD mortality and approximately 5% of all-cause mortality. We wish to stimulate new studies that compare CHD with CHF/HF only, exploiting population data, excluding baseline prevalent heart diseases, including incidence cases and separately studies with large numbers of recruited individuals. These analyses may well be complemented by the use of the Fine-Gray variant of the Cox predictive model that, by the sub-distribution of hazard models, may enable identifying risk factors as the determinants of competition between groups of diseases. The aim is to better define the differences between CHD and CHF/HF along with the possible etiology and even specific risk factors of these independent CHF/HF cases. A surge of interest among the investigators should thus be stimulated. Eventually, also for this “character” (in Pirandello’s acception), an author may hopefully be found, thus complementing with etiology an apparently orphan condition.