Impact of energy loss index on left ventricular mass regression after aortic valve replacement

Concomitant Septal Myectomy with Aortic Valve Replacement for Severe Aortic Stenosis with Left Ventricular Outflow Tract Obstruction

Objectives

Septal myectomy confers survival benefits on patients with hypertrophic cardiomyopathy. However, its role in the treatment of severe aortic stenosis (sAS) with left ventricular outflow tract obstruction (LVOTO) remains under investigation. Another challenging question in the era of transcatheter aortic valve replacement is who would benefit more from traditional surgical aortic valve replacement (SAVR) with myectomy. Therefore, this study aimed to investigate myectomy cases at our hospital in Japan.

Methods

A total of 740 patients who underwent SAVR for sAS between 2012 and 2019 were identified. The demographics and baseline echocardiographic findings were retrospectively compared between patients who underwent concomitant myectomy and those who did not. The myectomy group was further assessed for factors predisposing to LVOTO, operative details, echocardiographic changes, and prognosis. The resected septa were histopathologically analyzed.

Results

The myectomy group mostly comprised elderly females with a small hypercontractile heart. Myectomy with SAVR led to statistically significant improvements in concentric left ventricular hypertrophy and LVOTO parameters. Survival was comparable with that reported in previous reports, even in the elderly subset (≥ 75 years). The septa showed mild fibrosis.

Conclusions

Myectomy can be safely performed with SAVR for sAS with LVOTO, even in the elderly, and it effectively improves LVOTO. Special attention should be paid to elderly females with relatively more severe AS and a small yet extra-hypertrophic and extra-hypercontractile heart. Such patients warrant comprehensive assessment of LVOTO, and despite its invasiveness, SAVR may be potentially more beneficial by allowing direct observation of LVOTO and ancillary myectomy.

Non-invasive determination of pressure recovery by cardiac MRI and echocardiography in patients with severe aortic stenosis: short and long-term outcome prediction

OBJECTIVE

To assess the influence of pressure recovery (PR)-corrected haemodynamic parameters on outcome in patients with aortic stenosis.

METHODS

Aortic stenosis severity parameters were corrected for PR (increase in static pressure due to decreasing dynamic pressure), assessed using transthoracic echocardiography (TTE) or cardiac magnetic resonance imaging (CMR), in patients with aortic stenosis. PR, indexed PR (iPR) and energy loss index (ELI) were determined. Factors that predicted all-cause mortality, and 9-month or 10-year New York Heart Association classification ≥2 were assessed using Cox proportional hazards regression.

RESULTS

A total of 25 patients, aged 68 ± 10 years, were included. PR was 17 ± 6 mmHg using CMR, and CMR correlated with TTE measurements. PR correction using CMR data reduced the AS-severity classification in 12-20% of patients, and correction using TTE data reduced the AS-severity classification in 16% of patients. Age (Wald 4.774) was a statistically significant predictor of all-cause mortality; effective orifice area (Wald 3.753) and ELI (Wald 3.772) almost reached significance.

CONCLUSIONS

PR determination may result in significant reclassification of aortic stenosis severity and may hold value in predicting all-cause mortality.

Hemodynamic performance and incidence of patient-prosthesis mismatch of small-sized Trifecta pericardial aortic valves

OBJECTIVES

Small-sized bioprosthetic valves are sometimes associated with suboptimal hemodynamic performance, leading to a patient-prosthesis mismatch. Trifecta pericardial valves are designed to improve hemodynamic performance. The purpose of this study was to investigate the hemodynamic properties of small-sized Trifecta valves and their efficacy in preventing a patient-prosthesis mismatch.

METHODS

This was a retrospective analysis of 108 patients undergoing surgical aortic valve replacement with a Trifecta valve of 23 mm or less in a single Japanese institution. The hemodynamic performance was evaluated with an echocardiography examination in all patients after surgery, and the development of a patient-prosthesis mismatch was judged with the measured in vivo indexed effective orifice area.

RESULTS

There was one early and seven late mortalities. There were no valve explants due to structural valve deterioration. Postoperative mean pressure gradients of 19-, 21-, and 23-mm valves were 15.1, 11.4, and 9.0 mmHg, respectively. The effective orifice area of 19-, 21-, and 23-mm valves was 1.41, 1.69, and 1.78 cm², respectively. Patient-prosthesis mismatch occurred in 14 patients (1 severe and 13 moderate) and the incidence was 13.0% (15.4% in 19 mm, 18.0% in 21 mm, and 3.3% in 23 mm).

CONCLUSIONS

The small-sized Trifecta valves showed excellent hemodynamic performance and were associated with a low incidence rate of patient-prosthesis mismatch.

Evolving new concepts in the assessment of aortic stenosis

Echocardiography has been pivotal in evaluating aortic stenosis (AS) over the past several decades. Recent experience has shown a wide spectrum in the clinical presentation of AS. A better understanding of the underlying hemodynamic principles has resulted in emergence of new subtypes of AS. New treatment modalities have also been introduced, requiring precise evaluation of aortic valve (AV) pathology for implementation of these therapies. This review will discuss new concepts and indices in the use of echocardiography in patients with AS. Specifically, we will address the hemodynamic characteristics, clinical presentation, and management of normal-flow, high-gradient; paradoxical low-flow, low-gradient; and classical low-flow, low-gradient aortic stenoses.