Long-Term Outcome of Myectomy Associated With Secondary Mitral Valve Chordal Cutting in Obstructive Hypertrophic Cardiomyopathy.

BACKGROUND

The recent introduction of cardiac myosin inhibitors has modified the therapy of left ventricular outflow obstruction in patients with hypertrophic cardiomyopathy (HCM) and is raising uncertainties regarding the future role of surgery in the management of obstructive HCM. However, it is likely that a proportion of patients will continue to present with advanced, highly symptomatic HCM, despite medical therapy, and require surgical intervention. We previously reported the short-term results of cutting anterior mitral leaflet secondary chordae in combination with septal myectomy in patients with obstructive HCM. This operative approach has shown excellent results in several short-term studies from our and other centers. However, no data are currently available regarding the long-term outcome of this novel surgical procedure.

OBJECTIVES

The study sought to investigate the long-term results of myectomy associated with chordal cutting.

METHODS

Long-term results were assessed in 350 consecutive patients with obstructive HCM who underwent this operation at our center over a 5-year period. Median follow-up was 5.6 years (Q1-Q3: 4.2-6.3 years).

RESULTS

Including 2 in-hospital deaths (surgical mortality 0.6%), 6-year overall survival after surgery was 96% and did not differ from that of the general Italian population matched for age and sex (P = 0.331). Follow-up information was available in 344 (99%) patients. At the most recent evaluation, 271 (79%) patients were asymptomatic in NYHA functional class I, 65 (19%) were in NYHA functional class II, and 8 (2%) were in NYHA functional class III. During follow-up, there were 14 deaths, 6 of which were unrelated to HCM. At most recent echocardiographic evaluation, ≥95% of patients had no residual left ventricular outflow gradient, clinically significant mitral regurgitation, or impaired systolic function.

CONCLUSIONS

Our results show that cutting thickened and/or retracted secondary chordae of the anterior mitral leaflet in association with septal myectomy has excellent long-term clinical and hemodynamic results in patients with obstructive HCM. These findings may further increase the number of myectomy referral centers and the availability of the surgical option for severely symptomatic HCM patients unresponsive to medical treatment.