MA, a 28 years old male with a diagnosis of OHCM since 2008, came to our attention for effort dyspnea (NYHA II) and fatigue limiting his greengrocer activity. Decompensated T1DM (HbA1C 12%), HTN, obesity (BMI 37). In 2017 he implanted a bicameral ICD in primary prevention, later extracted for sepsis and replaced with S-ICD. In the last 2 years he had 3-4 episodes of FAP, the latter causing an AHF requiring hospitalization in ICU. CV therapy: metoprolol 100 mg bid; disopyramide 100 mg x 3; rivaroxaban 20 mg die, insulin. Resting ECG: sinus bradycardia, HR 50 bpm, LVH with secondary repolarization abnormalities, long QTc (>500 ms). At basal and stress echocardiography (Fig. 1) he had a maximum wall thickness at medium IVS of 21 mm and severe dynamic obstruction due to complete SAM (Gmax 50 -> 135 mmHg); moderate mitral regurgitation, secondary to SAM, with eccentric jet; worsening of obstruction and MR at peak of stress (Gmax 145 mmHg; MR 3+); absence of pulmonary hypertension; severe left atrial dilatation (53ml/mq). He was considered not eligible for Morrow myectomy due to unfavorable anatomy (basal IVS of 11-14 mm, maximum thickness at medium IVS). Mitral valve area was > 4cmq. After Heart Team evaluation the patient was proposed for a reparative approach of mitral valve, and TEER was preferred to open surgery for favorable anatomy and to avoid an increased peri-operative risk in a patient with different comorbidities. The procedure was successfully conducted with the implantation of 1 MitraClip (MITRACLIP® Evalve – Abbott) in central position, with echocardiographic evidence (Fig. 2) of complete SAM resolution, reduction of MR to 1+ and gradient abolition (13 mmHg post-Valsalva maneuver). MVA at intraoperative TEE: >2 cmq.
At six-months follow-up the patient reported a satisfactory reduction of symptoms without limitations in non-agonist physical activity and work, yet he still was not asymptomatic. Although on best medical treatment and after TEER, transthoracic echocardiographic control showed a recurrence of SAM and LVOTO (40 mmHg at basal, 70 mm Hg post – Valsalva maneuver). He is still candidate to myosin inhibition treatment.
This case highlights the multiple challenges of LVOTO in HCM patients. Although a hybrid approach may be a promising treatment of OHCM, especially in youngers, an increase of expertise in this field and further research is needed, focusing on predictors of procedural failure and success.