Methods: Consecutive sarcomeric HCM patients referred to our tertiary centre were evaluated by echocardiography at rest, after VM, after UP, and during exercise. Exclusion criteria were: lack of one of these provocative manoeuvres, apical HCM, hypertension >160 mmHg, and insufficient ultrasound quality.
Results: Over 225 patients evaluated from January 2016 to January 2018, we finally studied 130 patients (mean age 55.2±15.7 years, 72% male). Among those patients, 61% presented LVOT obstruction (LVOT gradient =30mmHg): 19% at rest, and 42% after one of the provocation manoeuvres (figure 1). The mean pressure gradient at rest was 15.5±25.9mmHg and increased at 24.4±34.8mmHg after VM, 24.5±34.2mmHg after UP, and 56.1±57.8mmHg at peak or after EE (p<0.001). Considering only the patients with latent provocable obstruction (n=55), 31% were obstructive after VM, 31% after UP, and 93% after EE.
Conclusion: Exercise is more sensitive than VM or UP to unmask maximal LVOT obstruction in HCM by echocardiography, and should be considered first in the management particularly to optimize symptoms therapy, but also for sudden cardiac death risk stratification. Nevertheless, VM and UP are also informative, particularly for patients who can’t perform exercise. Finally, the combination of the three manoeuvres allows to unmask more cases of obstruction in practice.