What is the clinical evidence from this study?

Study design: Cohort. Population: Hypertrophic obstructive cardiomyopathy (n=88). Intervention: Septal myectomy with secondary chordal resection (significant hypertrophy) vs. Septal myectomy with secondary chordal resection (mild hypertrophy). Primary outcome: Left ventricular outflow tract (LVOT) gradients at last follow-up (p=0.556).

What question did this study set out to answer?

This research aims to evaluate the mid-term postoperative outcomes of septal myectomy with chordal resection in different severities of hypertrophic obstructive cardiomyopathy.

May 8, 2026Open Access

Myectomy with secondary chordal resection in hypertrophic obstructive cardiomyopathy: the mid-term outcomes

Key Result

Septal myectomy with secondary chordal resection achieved comparable mid-term relief of left ventricular outflow tract obstruction in HOCM patients with significant versus mild septal hypertrophy.

Key Points

This research aims to evaluate the mid-term postoperative outcomes of septal myectomy with chordal resection in different severities of hypertrophic obstructive cardiomyopathy.
Single-center retrospective cohort study with nested case-control design
Involved 88 HOCM patients who underwent myectomy with chordal resection from 2014 to 2023
Patients were grouped based on septal thickness and followed for an average of 54 months.
No significant difference in LVOT gradients between significant and mild hypertrophy groups (P=0.556)
Interventricular septum was thicker in the significant hypertrophy group (P=0.016)
Recurrent mitral regurgitation rates were similar between groups (7.9% vs 8.0%, log-rank P=0.879).

Study Design

Type

Cohort (n=88)

Multicenter

Structured PICO

Does septal myectomy with secondary chordal resection achieve similar relief of LVOT obstruction in HOCM patients with significant versus mild septal hypertrophy?

Population

88 patients with hypertrophic obstructive cardiomyopathy (HOCM) who received septal myectomy with secondary chordal resection, median age 47.0, 48.9% male, single-center (China). Divided into significant hypertrophy (IVS > 18 mm, n=63) and mild hypertrophy (IVS ≤ 18 mm, n=25).

Intervention

Septal myectomy with secondary chordal resection (SM-SCR) in patients with significant septal hypertrophy (IVS > 18 mm)

Comparator

Septal myectomy with secondary chordal resection (SM-SCR) in patients with mild septal hypertrophy (IVS ≤ 18 mm)

Outcome

Relief of the left ventricular outflow tract (LVOT) obstruction, reflected by the interventricular septum (IVS) thickness and the LVOT gradients during the last follow-upsurrogate

Septal myectomy with secondary chordal resection provides comparable mid-term relief of LVOT obstruction and low rates of recurrent mitral regurgitation in HOCM patients regardless of baseline septal hypertrophy severity.

Main Result

Absolute Event Rate: 10% vs 8%

p-value: p=0.556

Limitations

Single-center retrospective study design
Relatively limited sample size which might influence statistical power
Small number of patients with recurrent mitral regurgitation making it difficult to identify specific predictors

Abstract

BACKGROUND: It is not clear whether septal myectomy with secondary chordal resection (SM-SCR) can achieve similar postoperative outcomes among hypertrophic obstructive cardiomyopathy (HOCM) patients exhibiting different severity of septal hypertrophy. METHODS: This was a single-center retrospective cohort study with a nested case-control study. HOCM patients received SM-SCR between 2014 and 2023 were retrospectively included and were grouped based on their septal thickness. The main outcome was the relief of the left ventricular outflow tract (LVOT) obstruction. Besides, predictors for recurrent mitral regurgitation (MR) were also explored. RESULTS: A total of 88 patients were included, with 63 in the significant hypertrophy group (SH group) and 25 in the mild hypertrophy group (MH group). The overall median follow-up time was 54.0 (33.0-79.0) months. Before adjusting the covariates, The LVOT gradients at the last follow-up were similar between groups SH group vs. MH group: 10.0 (6.0-14.0) mmHg vs. 8.0 (6.0-11.5) mmHg, P = 0.556, while the interventricular septum (IVS) was thicker for the SH group 15.0 (12.0-17.0) mm vs. 13.0 (11.0-14.0) mm, P = 0.016. In the fully adjusted model, both the LVOT gradients and the IVS thickness were comparable (P = 0.606 and 0.520 respectively). The risk of recurrent MR was similar between groups (7.9% vs. 8.0%, log-rank P = 0.879), while no predictors for recurrent MR were identified. CONCLUSION: According to our single-center data, the mid-term outcomes after SM-SCR were comparable for HOCM patients with different severity of septal hypertrophy. However, further investigations with larger sample sizes and longer follow-up durations are needed. TRIAL REGISTRATION: The study was approved by the Institutional Review Board 2023(2408), and patients' consents were waived due to the retrospective nature of the study.

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