Transapical Edge-to-Edge Repair for Systolic Anterior Motion in Obstructive Hypertrophic Cardiomyopathy

Abstract

Transapical mitral valve edge-to-edge repair (TA-TEER) offers a therapeutic option for obstructive hypertrophic cardiomyopathy with severe mitral regurgitation and systolic anterior motion. In this case series, we present 3 elderly patients with obstructive hypertrophic cardiomyopathy who underwent TA-TEER after declining conventional surgical options. Patient 1: A 66-year-old woman achieved immediate resolution of mitral regurgitation and systolic anterior motion, but developed hemolysis and hypotension at 2 weeks, requiring mechanical valve replacement. Patient 2: A 65-year-old man showed sustained improvement with resolved mitral regurgitation and systolic anterior motion at 4-month follow-up. Patient 3: A 70-year-old woman demonstrated immediate resolution with stable results. TA-TEER successfully addressed mitral regurgitation and systolic anterior motion in all cases, though 1 patient experienced serious complications requiring reoperation. Although TA-TEER may serve as a salvage option for high-risk patients, careful patient selection and awareness of potential complications are essential.

Visual Summary

Visual Summary.

Summary of TA-TEER for SAM in Obstructive Hypertrophic Cardiomyopathy

(A) Preprocedural anatomy showing an elongated anterior mitral leaflet with SAM, causing LVOT obstruction. (B) TA-TEER mechanism, with clip placement restricting leaflet motion. (C) Postprocedural result with resolution of SAM and reduced LVOT gradient. The key learning points—careful patient selection, importance of clip positioning, and need for close surveillance—are highlighted. LVOT = left ventricular outflow tract; SAM = systolic anterior motion; TA-TEER = transapical transcatheter edge-to-edge repair.

Obstructive hypertrophic cardiomyopathy (HCM) presents therapeutic challenges when accompanied by severe mitral regurgitation (MR) and systolic anterior motion (SAM). According to the 2024 American Heart Association/American College of Cardiology guideline and 2023 European Society of Cardiology guidelines, septal reduction therapy is recommended for eligible patients with obstructive HCM who remain symptomatic despite medical therapy.^1,2 Traditional surgical approaches, including septal myectomy and alcohol septal ablation, carry significant risks, particularly in elderly patients or those with multiple comorbidities.

Take-Home Messages

• •Transapical transcatheter edge-to-edge repair may offer a salvage option for selected patients with obstructive hypertrophic cardiomyopathy and systolic anterior motion–predominant obstruction who decline or are unsuitable for conventional septal reduction therapy.
• •Clip displacement with hemolysis can occur and requires vigilant early echocardiographic surveillance and low threshold for reintervention.

Transcatheter edge-to-edge repair (TEER) has been established as an effective treatment for primary and secondary MR in patients at high surgical risk.^3,4 The transapical approach offers certain advantages, including direct access to the mitral valve without transseptal puncture and improved coaxial alignment with the mitral valve plane.⁵ Recent case reports have suggested the potential utility of TEER in managing SAM associated with obstructive HCM.6, 7, 8 We present a series of 3 cases illustrating the application of transapical TEER (TA-TEER) in this complex clinical scenario, with particular attention to patient selection, procedural considerations, and potential complications.

Case Presentations

Patient 1: Initial success followed by complications

A 66-year-old woman presented with needle-like chest pain radiating to the left shoulder persisting for over 1 year, refractory to pharmacological therapy including β-blockers and calcium-channel blockers. She experienced multiple episodes of exercise-induced syncope. Transthoracic echocardiography (TTE) demonstrated basal thickening of the anterior interventricular septum (diastolic wall thickness 16 mm) with redundant mitral valve leaflets. The anterior mitral leaflet (AML) length was 24 mm and the posterior leaflet length was 17.5 mm, with a coaptation-septum (C-Sept) distance of 15 mm. The resting left ventricular outflow tract (LVOT) peak pressure gradient was 22 mm Hg; during the Valsalva maneuver, that gradient increased to 150 mm Hg with SAM and mild MR (effective regurgitant orifice 0.11 cm²). Transesophageal echocardiography (TEE) confirmed MR originating from the A2 segment (Figures 1A to 1D).

Figure 1.

Patient 1: Imaging Findings Before, During, and After TA-TEER

(A) Transthoracic echocardiography in M-mode demonstrating a systolic anterior motion sign (red arrow). (B) Transthoracic echocardiography showing a left ventricular outflow tract velocity with a peak pressure gradient of 150 mm Hg. (C) Transesophageal echocardiography demonstrating systolic anterior motion of the mitral valve (red arrow). (D) Three-dimensional transesophageal echocardiography showing eccentric mitral regurgitation during systole. (E) Transesophageal echocardiography showing the mitral valve clip position (blue arrow). (F) Transesophageal echocardiography of the left ventricular outflow tract post–TA-TEER. (G) Transthoracic echocardiography in the 4-chamber view showing the displaced clip (blue arrow). (H) Transthoracic echocardiography at 2 weeks postprocedure showing a left ventricular outflow tract velocity with a peak pressure gradient of 101 mm Hg, indicating clip migration. TA-TEER = transapical transcatheter edge-to-edge repair.

LVOT obstruction was determined to be primarily SAM-mediated, given the elongated AML and narrow C-Sept distance. This anatomical configuration, combined with only mild septal hypertrophy (16 mm), suggested that addressing the SAM component could effectively reduce the LVOT gradient. After the patient’s refusal of alcohol septal ablation and Morrow surgery, TA-TEER was offered after multidisciplinary heart team discussion.

The transapical approach was selected because of: 1) small left atrium (30 mm) limiting transseptal maneuverability; 2) steep mitral valve angle favoring direct apical access; and 3) surgical team experience with transapical procedures.

TA-TEER was performed using the ValveClamp system (Hanyu Medical Technology) (21-mm clip) at the A2-P2 position. Intraoperative TEE demonstrated resolution of MR and SAM (Figure 1E and 1F), with the LVOT gradient reduced to 19 mm Hg and a mitral valve mean gradient of 3 mm Hg at a heart rate of 72 beats/min. The patient was discharged within 1 week.

Two weeks postoperatively, the patient presented with gross hematuria and hypotension. TTE revealed that the LVOT gradient increased to 101 mm Hg; TEE showed clip displacement toward the LVOT (Figure 1G and 1H). Mechanical mitral valve replacement was performed without myectomy, as intraoperative findings indicated that clip malposition rather than residual septal hypertrophy was the primary issue. The patient recovered well with a postoperative LVOT gradient of 16 mm Hg.

Patient 2: Successful outcome with stable results

A 65-year-old man presented with a 7-year history of progressive dyspnea unresponsive to pharmacological therapy and multiple episodes of exercise-induced syncope. TTE revealed anterior septal thickening (diastolic wall thickness 17 mm; length 20 mm), resting LVOT maximum flow velocity 4.59 m/s (peak pressure gradient 84 mm Hg), redundant mitral valve leaflets (anterior leaflet length 30 mm; posterior leaflet length 17 mm; C-Sept distance 17 mm) with SAM and moderate MR (effective regurgitant orifice 0.30 cm²; regurgitant volume 50 mL). TEE localized MR primarily to the A2 segment (Figures 2A to 2D).

Figure 2.

Patient 2: Successful Outcome With Stable Results

(A) Transthoracic echocardiography in M-mode demonstrating a systolic anterior motion sign (red arrow). (B) Transthoracic echocardiography measuring a left ventricular outflow tract velocity with a peak pressure gradient of 84 mm Hg. (C) Transesophageal echocardiography showing systolic anterior motion of the mitral valve (red arrow). (D) Three-dimensional transesophageal echocardiography showing eccentric mitral regurgitation during systole. (E) Transesophageal echocardiography showing the mitral valve clip position (blue arrow). (F) Transesophageal echocardiography showing a left ventricular outflow tract velocity immediately after transapical transcatheter edge-to-edge repair (peak pressure gradient 13 mm Hg). (G) Transthoracic echocardiography in the 4-chamber view showing the stable clip position (blue arrow). (H) Transthoracic echocardiography showing a left ventricular outflow tract velocity at 4-month follow-up with a peak pressure gradient of 18 mm Hg.

After the patient’s refusal of alcohol septal ablation and open-heart Morrow surgery, TA-TEER was performed using the ValveClamp system (21-mm clip), with clip placement at the A2-P2 position. Both MR and SAM resolved immediately, with an LVOT flow rate of 1.83 m/s (peak pressure gradient 13 mm Hg) and a mitral valve mean gradient of 2 mm Hg at a heart rate of 68 beats/min (Figure 2E and 2F). The patient remained symptom-free and was discharged within 1 week. Four-month follow-up demonstrated sustained improvement, with LVOT flow velocity maintaining a low peak pressure gradient (18 mm Hg) (Figure 2G and 2H), a mitral valve mean gradient of 3 mm Hg, no significant MR, and NYHA functional class II symptoms.

Patient 3: Successful outcome with stable results

A 70-year-old woman presented with a 3-year history of progressive dyspnea refractory to pharmacological therapy and multiple episodes of exercise-induced syncope. TTE demonstrated basal thickening of the anterior septum (diastolic wall thickness 15 mm; length 20 mm), resting LVOT maximum flow velocity 4.74 m/s (peak pressure gradient 90 mm Hg), redundant mitral valve leaflets (anterior leaflet length 19 mm; posterior leaflet length 16 mm; C-Sept distance 14 mm) with SAM and significant eccentric MR (effective regurgitant orifice 0.40 cm²; regurgitant volume 69 mL). TEE identified MR primarily at the A2 segment (Figure 3A and 3B).

Figure 3.

Patient 3: Imaging Findings and Stable Results

(A) Transesophageal echocardiography showing systolic anterior motion of the mitral valve (red arrow). (B) Transesophageal echocardiography measuring a left ventricular outflow tract velocity with a peak pressure gradient of 90 mm Hg. (C) Transesophageal echocardiography showing the mitral valve clip position (blue arrow). (D) Transesophageal echocardiography showing a left ventricular outflow tract velocity immediately after –transapical transcatheter edge-to-edge repair (peak pressure gradient 22 mm Hg). (E) Transthoracic echocardiography showing a long-axis view of the cardiac base with the stable clip position (blue arrow). (F) Transthoracic echocardiography showing a left ventricular outflow tract velocity at 1-month follow-up with a peak pressure gradient of 21 mm Hg.

After the patient’s refusal of alcohol septal ablation and open-heart Morrow surgery, TA-TEER was performed using the ValveClamp system (19-mm clip), with clip placement at the A2-P2 position. Both MR and SAM resolved, with an LVOT flow rate of 2.32 m/s (peak pressure gradient 22 mm Hg) and a mitral valve mean gradient of 3 mm Hg at a heart rate of 75 beats/min (Figure 3C and 3D). The patient remained symptom-free and was discharged within 1 week. One-month follow-up echocardiography showed a mild increase in LVOT flow velocity compared to immediate postoperative period (peak pressure gradient 21 mm Hg) (Figure 3E and 3F), a mitral valve mean gradient of 3 mm Hg, trace MR, and NYHA class II symptoms.

Discussion

This limited case series provides preliminary observations regarding the feasibility of TA-TEER in selected patients with obstructive HCM presenting with concomitant MR and SAM. Although the initial results suggest potential therapeutic benefit, the small sample size (n = 3) and short follow-up duration necessitate further validation in larger cohorts.

All 3 patients demonstrated immediate procedural success with resolution of MR and SAM, accompanied by measurable reductions in LVOT gradients (mean reduction from 108.0 ± 36.5 to 18.0 ± 4.6 mm Hg immediately after the procedure) (Table 1). However, it is important to note that 1 patient experienced significant complications requiring surgical reintervention, highlighting the potential risks associated with this approach.

Table 1.

Patient Characteristics, Procedural Data, and Outcomes

	Patient 1	Patient 2	Patient 3
Demographic characteristics
Age, y	66	65	70
Sex	Female	Male	Female
NYHA functional class	III	III	III
Baseline echocardiography
Septal thickness, mm	16	16	15
LA(A-P)	30	38	31
AML length, mm	24	30	19
PML length, mm	17.5	17	16
C-Sept distance, mm	15	17	14
Peak LVOT gradient, mm Hg	150	84	90
ERO, cm2	0.11	0.30	0.40
Regurgitant volume, mL	7	50	69
Procedural data
Clip size, mm	21	21	19
MV mean gradient, mm Hg	3	2	3
Heart rate, beats/min	72	68	75
Postprocedure LVOT gradient, mm Hg	19	13	22
Follow-up
Duration, mo	0.5a	4	1
Final LVOT gradient, mm Hg	16b	18	21
MR grade	0b	0	0
NYHA class	IIb	II	II

AML = anterior mitral leaflet; C-Sept = coaptation-septum; ERO = effective regurgitant orifice; LA(A-P) = left atrium anteroposterior diameter, mm; LVOT = left ventricular outflow tract; MR = mitral regurgitation; MV = mitral valve; PML = posterior mitral leaflet.

^aPatient required reoperation at 2 wk because of clip migration and hemolysis.

^bValues obtained after mitral valve replacement surgery.

Our anatomical observations revealed a consistent pattern of mild basal interventricular septal thickening (mean thickness 15.7 ± 0.6 mm) combined with elongated AML (mean 24.3 ± 5.5 mm) and narrow C-Sept distance (mean 15.3 ± 1.5 mm). This finding suggests that LVOT obstruction in this patient subset may be predominantly SAM-mediated rather than due to isolated septal hypertrophy. The mechanism by which TEER ameliorates SAM involves mechanical restriction of anterior leaflet excursion through edge-to-edge approximation, reducing the Venturi effect and drag forces.^9,10

The development of hemolysis and hemodynamic compromise in patient 1 warrants particular attention. Clip displacement toward the LVOT with associated hemolysis likely resulted from the combination of a small left ventricular (LV) cavity and hyperdynamic systolic function generating forces promoting clip migration. The occurrence of hemolysis, a rare but well-documented complication of transcatheter mitral interventions, likely resulted from high-velocity turbulent flow through residual regurgitant jets adjacent to the displaced clip.^11,12 To avoid such complications, we recommend: 1) meticulous preprocedural 3-dimensional TEE assessment including LV dimensions, septal morphology, and mitral valve anatomy; 2) careful clip size selection with consideration of sizing down in small LV cavities; 3) optimal clip positioning perpendicular to the coaptation line and close to the posterior leaflet to minimize LVOT encroachment; 4) early echocardiographic surveillance at 1 to 2 weeks; and 5) low threshold for intervention if gradient increase or hemolysis occurs.

One potential advantage of the transapical approach is the possibility of combining TA-TEER with transapical septal reduction therapy in a single procedure. For patients with both SAM-related obstruction and significant septal hypertrophy, such a combined approach could address both pathophysiological mechanisms. However, this remains speculative and would require careful patient selection and further investigation.

The limitations of this study are substantial and must be acknowledged. The small sample size precludes any definitive conclusions regarding efficacy or safety. The absence of a control group prevents comparative effectiveness assessment against established therapies such as surgical myectomy or alcohol septal ablation. Follow-up duration is insufficient to evaluate long-term outcomes, durability, or late complications.

Conclusions

TA-TEER may represent a potential therapeutic option for highly selected patients with obstructive HCM who are unsuitable for conventional interventions, particularly those with SAM-predominant obstruction and elongated mitral leaflets. However, the significant complication observed in 1 patient underscores the need for careful patient selection, meticulous procedural technique, and close postoperative monitoring. Larger prospective studies are needed to define the role of this approach in the treatment algorithm for obstructive HCM.

Funding Support and Author Disclosures

This work was supported by the Key R&D Program of Shaanxi Province (2021SF-140, 2024SF-YBXM-395). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.