Hypertrophic cardiomyopathy with moderate septal thickness and mitral regurgitation: long-term surgical results

Abstract

OBJECTIVES The aim of this study was to assess the long-term outcomes of different surgical strategies in patients with hypertrophic obstructive cardiomyopathy (HOCM) with septal thickness ≤18 mm and systolic anterior motion (SAM)-related moderate-to-severe mitral regurgitation (MR). METHODS Seventy-six HOCM patients with septal thickness 17 [16; 18] mm, resting left ventricle outflow tract gradient 60 [41; 85] mmHg and SAM-related MR ≥2+/4+, underwent septal myectomy alone (54%) or mitral valve (MV) surgery ± myectomy (46%). RESULTS No hospital death and no ventricular septal defect occurred. Patients undergoing MV surgery ± myectomy had longer cardiopulmonary bypass and X-clamp times (77 [60–106] vs 51 [44–62] min, P < 0.001 and 56 [45–77] vs 32 [28–41] min, P < 0.001) and higher incidence of low output syndrome (11% vs 0%, P = 0.04). Follow-up was 98.6% complete, median 8 years [3–11]. There were no statistically significant differences in overall survival (P = 0.069) with survival rates at 9 years of 96 ± 4% in the myectomy alone group and 81 ± 8% in the MV surgery ± myectomy one. At 9 years, cumulative incidence function of cardiac death was 12 ± 6% in the MV surgery ± myectomy group vs 0% in the myectomy one, P = 0.06. Multivariable analysis identified age and previous septal alcoholization as predictors of cardiac death (hazard ratio (HR) = 1.1, 95% confidence interval (CI) 1.0–1.1, P = 0.004 and HR = 2.9, 95% CI 1.0–8.3, P = 0.042). The 9-year cumulative incidence function of recurrence of MR ≥2+, with death as competing risk, was 3 ± 2.8% in the MV surgery ± myectomy group vs 25 ± 6.9% in the myectomy one, P = 0.005. CONCLUSIONS In HOCM patients with moderate septal thickness and SAM-related MR, as the degree of septal hypertrophy decreases, addressing the abnormalities of the MV apparatus may become necessary to provide a durable resolution of left ventricle outflow tract obstruction and SAM-related MR. However, performing myectomy alone, whenever possible, seems to be associated to a better postoperative course and a trend towards lower cardiac mortality at follow-up, despite a higher rate of residual moderate MR.

Transaortic Shallow Septal Myectomy and Cutting of Secondary Fibrotic Mitral Valve Chordae—A 5-Year Single-Center Experience in the Treatment of Hypertrophic Obstructive Cardiomyopathy

“…Preoperatively, the majority of our subjects (59%) were either in NYHA class III or IV, with a mean IVS thickness of 24 ± 6 mm and a mean LVOT gradient of 93 ± 33 mmHg. In addition, postoperative outcomes at hospital discharge are in line with those observed in other surgical cohorts, with significant reduction in peak resting/provoked intraventricular gradient and significant improvement in heart failure symptoms [ 11 , 13 , 14 ]. A postoperative residual gradient of >30 mmHg was noticed in only 5 (6%) patients, consistent with literature data [ 14 , 15 ].…”

Septal Thickness Does Not Impact Outcome After Hypertrophic Obstructive Cardiomyopathy Surgery (Septal Myectomy and Subvalvular Mitral Apparatus Remodeling): A 15-Years of Experience

“…The patients had peak LVOT gradients ≥ 50 mmHg at rest or during stress and drug-refractory disabling symptoms ( 17 ) and were divided in 2 groups according to the septal thickness: moderate [< 18 mm, 29 patients (44%)] and severe [≥ 18 mm, 37 patients (56%)]. The cutoff of 18 mm was decided according to data available in the literature ( 7 , 8 ). The 66 patients operated on represent 37% of 178 patients referred to our dedicated hypertrophic obstructive cardiomyopathy out-patient clinic who underwent surgery.…”

“…Transaortic surgical septal myectomy ( 1 ) for the treatment of hypertrophic obstructive cardiomyopathy (HOCM) is associated with low operative morbidity and mortality, and reduction of the outflow gradient ( 2 , 3 ). Systolic anterior motion (SAM) of the anterior mitral leaflet (AML) as a contributor to the pathophysiology of left ventricle outflow tract (LVOT) obstruction has been addressed ( 4 – 6 ) and in patients without severe hypertrophy ( 7 , 8 ), SAM and mitral abnormalities (e.g., leaflet elongation and a wide array of malformations of the papillary muscles (PM) and chordae) may influence the dynamic obstruction of LVOT. In this context, the correction of subvalvular mitral apparatus abnormalities in addition to septal myectomy has been advocated ( 6 , 8 , 9 ) in order to abolish the LVOT gradient and to restore mitral competence.…”

“…In this context, the correction of subvalvular mitral apparatus abnormalities in addition to septal myectomy has been advocated ( 6 , 8 , 9 ) in order to abolish the LVOT gradient and to restore mitral competence. Although a matter of debate ( 10 ), these procedures include secondary chordae cutting ( 11 ), anterior leaflet plication ( 12 ) or extension ( 13 ), reorientation of PM ( 14 ), edge-to-edge repair ( 15 ), and mitral valve (MV) surgery ( 6 , 7 , 9 , 16 ). MV replacement has been also reported ( 7 , 16 ) if SAM and severe mitral regurgitation (MR) are challenging to manage.…”

“…Although a matter of debate ( 10 ), these procedures include secondary chordae cutting ( 11 ), anterior leaflet plication ( 12 ) or extension ( 13 ), reorientation of PM ( 14 ), edge-to-edge repair ( 15 ), and mitral valve (MV) surgery ( 6 , 7 , 9 , 16 ). MV replacement has been also reported ( 7 , 16 ) if SAM and severe mitral regurgitation (MR) are challenging to manage.…”