Bisoprolol for treatment of symptomatic patients with obstructive hypertrophic cardiomyopathy. The BASIC (bisoprolol AS therapy in hypertrophic cardiomyopathy) study

Aims: To evaluate the role of bisoprolol to control symptoms and left ventricular outflow tract obstruction (LVOTO) in a consecutive cohort of adults with hypertrophic cardiomyopathy (HCM). Methods and results: In this retrospective study, patients with HCM with an LVOT gradient >= 50 mmHg after Valsalva manoeuvre and New York Heart Association (NYHA) class II-III symptoms were assigned to receive bisoprolol (starting at 1.25 mg daily). The initial dose was increased every two weeks to achieve the target in LVOT gradient < 30 mmHg or the maximum tolerated dose. The primary endpoint was the achievement of a LVOT gradient < 30 mmHg and >= 1 NYHA class improvement. The secondary endpoints were proportion of patients with LVOT gradient < 30 mmHg or < 50 mmHg, proportion of patients with >= 1 NYHA class improvement, and change from baseline in LVOT gradient. Between December 2001 and December 2020, 92 patients were enrolled into the study. Sixteen (17%) patients on bisoprolol met the primary endpoint. Bisoprolol reduced the LVOT gradient to less than 30 mmHg in 33 (36%) patients, to less than 50 mmHg in 57 (62%), and improved NYHA class in 30 (33%). The mean reduction of LVOT gradient on bisoprolol was 28 (+/- 14) mmHg and the percentage reduction was 42 (+/- 21) %. In 35 (38%) patients, bisoprolol did not reduce the gradient to less than 50 mmHg requiring disopyramide and/or myectomy to achieve this goal. Conclusion: Treatment with bisoprolol was well-tolerated and effective in relieving obstruction and improving symptoms in a significant proportion of patients with symptomatic obstructive HCM.

Automated summary

Bisoprolol is effective and well-tolerated in controlling symptoms and left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy.