P1244Survival after septal myectomy in male and female patients with hypertrophic obstructive cardiomyopathy

In recent years, studies have debated the impact of gender on the presentation and clinical course of HCM, with research showing that at time of myectomy, women are older, have worse diastolic function and more advanced cardiac remodeling. The clinical impact of these differences is unknown. We included 221 HCM patients (57% men) who underwent septal myectomy and are followed in our center. Time to treatment was calculated in relation to symptom onset. Pre- and post-operative clinical and echocardiographic data were collected. Gender differences were assessed at baseline and in survival analyses for the composite endpoint of all-cause mortality, cardiac transplantation, re-intervention and aborted sudden cardiac death. Women were older at time of myectomy, but time until treatment was similar (table). Pre-operative echocardiographic indices were comparable among groups, but were significantly higher in women when correcting for body surface area. At three months, no differences were found in clinical and echocardiographic results. After 6.1 [2.9–10.1] years, 24% of women and 23% of men had reached the composite endpoint (p=0.30, figure). Gender comparison pre- and post-myectomy Men (n=125) Women (n=96) p value Age 49±14 54±17 0.02 Maximal wall thickness, mm 19.9±4.7 19.8±5.8 0.97 Indexed maximal wall thickness, mm/m2 9.8±2.5 11.5±4.5 0.001 Left atrial diameter, mm 48.1±7.3 45.9±7.3 0.06 Indexed left atrial diameter, mm/m2 23.5±3.5 26.5±7.5 0.002 LV end-diastolic diameter, mm 45.4±7.6 42.8±5.6 0.04 Indexed LV end-diastolic diameter, mm/m2 22.1±3.7 23.6±3.0 0.02 Gradient reduction, %* 75.1±25.0 72.9±28.6 0.63 Improvement in symptoms*† 97 (95%) 64 (89%) 0.34 MWT = maximal wall thickness; LV = left ventricle. *At three months follow-up; †Defined as a reduction of ≥1 NYHA class, measured in 102 men and 72 women. Survival after myectomy Although women present later in life and seem to have more advanced disease at time of myectomy, time to treatment is similar and survival after myectomy is excellent for both men and women.