Two Barricades in a Row Mixed Lesion of Dynamic Left Ventricular Outflow Tract Obstruction and Aortic Stenosis: Finding the Culprit for Decision Making

Case Report: Mechanical hemolysis resulting from left ventricular outflow tract obstruction after aortic valve replacement relieved by transapical beating-heart septal myectomy

Background

Aortic stenosis (AS) in combination with left ventricular outflow tract obstruction (LVOTO) has occasionally been reported. However, making a precise diagnosis and successfully treating this combination is challenging due to the hemodynamic interaction between the two conditions.

Case summary

A 56-year-old male patient who had been diagnosed with severe AS and asymmetric left ventricular hypertrophy underwent aortic valve replacement (AVR) and a conventional septal myectomy. Immediately after the procedure, significant systolic anterior motion and mitral regurgitation developed, necessitating a surgical mitral edge-to-edge repair. Ten days after the procedure, the patient developed hematuria and LVOTO, which was confirmed by echocardiography. Because the LVOTO might have been the cause of the hematuria, the patient underwent alcohol septal ablation, but this had little effect. Three months later, a transapical beating-heart septal myectomy (TA-BSM) was performed in our hospital. Postoperatively, the LVOTO had been significantly ameliorated and the hematuria had resolved.

Conclusion

For patients with AS and LVOTO due to a hypertrophic interventricular septum, inadequate amelioration of the LVOTO after AVR may lead to severe hemolytic hematuria. TA-BSM is a minimally invasive, safe, and effective surgical procedure for ameliorating LVOTO in patients with aortic valve prostheses.

Diagnostic Challenges in Aortic Stenosis

Aortic stenosis (AS) is the most prevalent degenerative valvular disease in western countries. Transthoracic echocardiography (TTE) is considered, nowadays, to be the main imaging technique for the work-up of AS due to high availability, safety, low cost, and excellent capacity to evaluate aortic valve (AV) morphology and function. Despite the diagnosis of AS being considered straightforward for a very long time, based on high gradients and reduced aortic valve area (AVA), many patients with AS represent a real dilemma for cardiologist. On the one hand, the acoustic window may be inadequate and the TTE limited in some cases. On the other hand, a growing body of evidence shows that patients with low gradients (due to systolic dysfunction, concentric hypertrophy or coexistence of another valve disease such as mitral stenosis or regurgitation) may develop severe AS (low-flow low-gradient severe AS) with a similar or even worse prognosis. The use of complementary imaging techniques such as transesophageal echocardiography (TEE), multidetector computed tomography (MDTC), or cardiac magnetic resonance (CMR) plays a key role in such scenarios. The aim of this review is to summarize the diagnostic challenges associated with patients with AS and the advantages of a comprehensive multimodality cardiac imaging (MCI) approach to reach a precise grading of the disease, a crucial factor to warrant an adequate management of patients.

Non-surgical management of an acute decompensated heart failure patient with severe aortic stenosis and concomitant left ventricular outflow tract obstruction

Acute decompensated heart failure (ADHF) due to severe aortic stenosis (AS) and concomitant left ventricular outflow tract (LVOT) obstruction is a serious condition. Treatment with medication alone is sometimes difficult, and the efficacy of further interventional strategies has not been fully elucidated. In patients with high surgical risks, combination therapy using transcatheter aortic valve replacement (TAVR) and percutaneous alcohol septal ablation (ASA) is used as a non-surgical intervention. However, this treatment cannot be performed under unstable hemodynamic conditions. This report highlights the utility and efficacy of emergent balloon aortic valvuloplasty (BAV) in controlling heart failure and its potential to serve as a bridge to curative therapy, even in older patients with ADHF due to severe AS with concomitant LVOT obstruction. Furthermore, combination therapy with TAVR and percutaneous ASA could be safely performed after controlling for ADHF using BAV. Non-surgical management is a more feasible treatment option in older patients with ADHF who are at higher risk of complications during surgical intervention.

<Learning objective: Management of acute decompensated heart failure (ADHF) due to severe aortic stenosis (AS) and concomitant left ventricular outflow tract (LVOT) obstruction can be difficult. Despite concomitant LVOT obstruction, emergent balloon aortic valvuloplasty is potentially useful and effective for controlling heart failure and could become a bridge to subsequent combination therapy using transcatheter aortic valve replacement and percutaneous alcohol septal ablation. This sequential non-surgical management is a novel strategy for older patients with high surgical risk and ADHF due to severe AS with concomitant LVOT obstruction.>