Outcomes in Patients Undergoing Surgical Myectomy with Concomitant Aortic Valve Replacement: Data of the Netherlands Heart Registration

BACKGROUND The objectives of this multicentre Dutch study were to evaluate outcomes of surgical myectomy with concomitant aortic valve replacement (AVR) in patients with hypertrophic cardiomyopathy (HCM) and aortic valve stenosis and to compare patient survival against age-sex-matched survival of the general Dutch population. METHODS All HCM patients who underwent surgical myectomy with concomitant AVR between 2012 and 2020 across 12 Dutch hospitals were analysed using data from the Netherlands Heart Registration. Operative details, pre-, and in-hospital echocardiographic data, and 30-day complication rates are described. Survival is assessed using Kaplan-Meier estimates and compared to the general Dutch population. RESULTS This cohort (n=94) included 41 males (44%) and 53 females (56%) with a median age of 72 (interquartile-range [IQR]: 67-76) years at the time of the intervention. Additional procedures to AVR were performed concomitantly in 54% of patients. Mean resting left ventricular outflow tract (LVOT) gradient improved from 73±27mmHg to 12±12 postoperatively. At baseline, septal thickness and indexed AV-area were 21 [19-24] mm, and 0.48±0.14cm2/m2, respectively. Permanent pacemaker implantation and ventricular septal defect rates were 13% and 1%, respectively. Unadjusted survival estimated at 1, and 6 years after the surgical procedure were 90% (95%CI, 85-97), and 71% (95%CI, 59-84). Age-and sex-matched survival in the general population was 83% (95%CI, 70%-97%) at 6-years. CONCLUSIONS Surgical myectomy with concomitant AVR effectively relieved LVOT-obstruction; however, permanent pacemaker implantation was a relatively common complication. At longer-term follow-up, these patients showed lower survival compared to the age- and sex-matched general Dutch population.