Hypertrophic cardiomyopathy (HCM), the most common inherited cardiovascular disease (1:500), is usually characterized by markedly heterogeneous morphologic, functional, and clinical spectra. Sudden cardiac death (SCD), albeit rare, is undoubtedly the most devastating clinical manifestation, however the development of heart failure (HF) represents the actual major concerns.
In recent years, we highlighted the possibility to achieve a global risk characterization of HCM patients throughout an accurate analysis of their functional capacity by means of cardiopulmonary exercise test (CPET). Anyway the pathophysiology of HCM exercise limitation still remains tremendously complex and, up to now, few studies specifically explored it multidimensionally (i.e. relationship between ECG, gas exchange, autonomic nervous system variables).
Therefore, following our recent research track, we plan to investigate the exercise capacity in a large cohort of stable HCM outpatients on optimized therapy. Specifically, we are going to organize two distinct protocols, the first focusing on the exercise capacity pathophysiology (single-center experimental study) whereas the second one on a possible prognostic role of some CPET variables.
As in heart failure, the pathophysiology of exercise limitation in HCM remains complex and, up to now, few studies specifically addressed this topic from a multidimensional viewpoint.
The present research includes two distinct protocols:
- the first represents an effort to dissect the mechanisms underlying the exercise impairment in HCM, to analyze their specific impact as well as their reciprocal relationships (i.e autonomic nervous system imbalance, maximal wall thickness, left ventricular outflow tract obstruction presence/magnitude, late-gadolinium enhancement presence/extension, chronotropic incompetence, etc). In such a study, we will use, for the first time, a multidimensional approach by adopting several noninvasive diagnostic tools: cardiopulmary exercise test, impedance measurement of haemodynamic variables, cardiac resonance imaging, heart rate and QT variability analysis both in the spatial and the temporal domain.
- the second arm is a retrospective Italian multicenter study on a prospectively (ongoing) database, including seven centers highly skilled in HCM management. The abovementioned database represents most likely one the largest and more detailed HCM European database and our research group ("Sapienza" University - A.O. Sant'Andrea) is actually the leader center.