A retrospective clinical study of transaortic extended septal myectomy for obstructive hypertrophic cardiomyopathy in China

Abstract

Objectives: The aim was to assess the early and mid-term clinical effects of transaortic extended septal myectomy (TAESM) on obstructive hypertrophic cardiomyopathy (HCM) in China.

Methods: Ninety-three consecutive patients [57 men; mean age 45.8 ± 13.4 (11-74) years] with obstructive HCM underwent TAESM in Fuwai hospital. Their clinical data were analysed retrospectively. All the patients had drug-refractory symptoms and left ventricular outflow tract (LVOT) obstruction with a resting or physically provoked gradient of ≥50 mmHg. Preoperative transthoracic, intra-operative transoesophageal and postoperative transthoracic echocardiography was performed to assess LVOT gradients, septal thickness, LVOT diameter, mitral valve function, etc. Systolic anterior motion (SAM) of the anterior mitral valve leaflet had been detected in all preoperatively.

Results: All the surgical procedures of the 93 patients were technically successful. The average length of postoperative stay was 7.8 ± 3.7 days. The 30-day and in-hospital mortality was 0%. Initial postoperative transoesophageal echocardiography (TEE) demonstrated marked reduction in LVOT gradient (91.76 ± 25.08 to 14.34 ± 13.44 mmHg, P < 0.0005) and significant improvement in mitral regurgitation (MR; P < 0.0005). Concomitant surgical procedures were carried out in 37 (39.8%). Complete atrioventricular block occurred in 3, complete left bundle branch block in 44, intraventricular conduction delay in 18, complete right bundle branch block in 2, transient renal dysfunction in 2 and transient intra-aortic-balloon-pumping was needed in 2. No other complications were observed during hospital stay. During a follow-up of 10.72 ± 11.02 (1-24) months, there were no readmissions or deaths, and all patients subjectively reported an obvious decrease in limiting symptoms and a significant increase in physical ability. At the latest follow-up, the New York Heart Association functional class decreased from 3.09 ± 0.60 (2-4) preoperatively to 1.12 ± 0.32 (1-2) (P < 0.0005); the LVOT gradient remained low at 14.78 ± 14.01 mmHg; MR remained absent (51) or at mild-(41)-to-moderate-(1) levels and SAM resolved completely in 98.9% (92 of 93) patients.

Conclusions: TAESM provides excellent relief from LVOT obstruction in HCM patients, with a conspicuous clinical and echocardiographic outcome at early and mid-term follow-up. For obstructive HCM and cardiac comorbidities, concomitant cardiac procedures with TAESM can be performed with low risk and satisfactory results.

Figure 1:

Abnormal muscle located between the anterior papillary muscle and the anterior leaflet of the mitral valve.

Figure 2:

The abnormal muscle bundle was cut off.

Figure 3:

Hypertrophic IVS was partially resected.

Figure 4:

The drawings show the extent of resection. We often try to resect the hypertrophied muscles as a whole mass.

Figure 5:

The drawings show the extent of resection, including abnormal muscles that are located between the anterior papillary muscle and the anterior leaflet of mitral valve.

Figure 6:

The resected muscle sample weighed 6.2 g (about 4 cm × 2 cm × 1.5 cm).