Tessari Fernanda Castiglioni, Lopes Maria Antonieta Albanez A de M, Campos Carlos M, Rosa Vitor Emer Egypto, Sampaio Roney Orismar, Soares Frederico José Mendes Mendonça, Lopes Rener Romulo Souza, Nazzetta Daniella Cian, de Brito Fábio Sândoli, Ribeiro Henrique Barbosa, Vieira Marcelo L C, Mathias Wilson, Fernandes Joao Ricardo Cordeiro, Lopes Mariana Pezzute, Rochitte Carlos E, Pomerantzeff Pablo M A, Abizaid Alexandre, Tarasoutchi Flavio
Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil.
Department of Hemodynamic, Real Hospital Português, Recife, Brazil.
Front Cardiovasc Med. 2023 Jun 12;10:1197408. doi: 10.3389/fcvm.2023.1197408. eCollection 2023.
Classical low-flow, low-gradient aortic stenosis (LFLG-AS) is an advanced stage of aortic stenosis, which has a poor prognosis with medical treatment and a high operative mortality after surgical aortic valve replacement (SAVR). There is currently a paucity of information regarding the current prognosis of classical LFLG-AS patients undergoing SAVR and the lack of a reliable risk assessment tool for this particular subset of AS patients. The present study aims to assess mortality predictors in a population of classical LFLG-AS patients undergoing SAVR.
This is a prospective study including 41 consecutive classical LFLG-AS patients (aortic valve area ≤1.0 cm, mean transaortic gradient <40 mmHg, left ventricular ejection fraction <50%). All patients underwent dobutamine stress echocardiography (DSE), 3D echocardiography, and T1 mapping cardiac magnetic resonance (CMR). Patients with pseudo-severe aortic stenosis were excluded. Patients were divided into groups according to the median value of the mean transaortic gradient (≤25 and >25 mmHg). All-cause, intraprocedural, 30-day, and 1-year mortality rates were evaluated.
All of the patients had degenerative aortic stenosis, with a median age of 66 (60-73) years; most of the patients were men (83%). The median EuroSCORE II was 2.19% (1.5%-4.78%), and the median STS was 2.19% (1.6%-3.99%). On DSE, 73.2% had flow reserve (FR), i.e., an increase in stroke volume ≥20% during DSE, with no significant differences between groups. On CMR, late gadolinium enhancement mass was lower in the group with mean transaortic gradient >25 mmHg [2.0 (0.0-8.9) g vs. 8.5 (2.3-15.0) g; = 0.034), and myocardium extracellular volume (ECV) and indexed ECV were similar between groups. The 30-day and 1-year mortality rates were 14.6% and 43.8%, respectively. The median follow-up was 4.1 (0.3-5.1) years. By multivariate analysis adjusted for FR, only the mean transaortic gradient was an independent predictor of mortality (hazard ratio: 0.923, 95% confidence interval: 0.864-0.986, = 0.019). A mean transaortic gradient ≤25 mmHg was associated with higher all-cause mortality rates (log-rank = 0.038), while there was no difference in mortality regarding FR status (log-rank = 0.114).
In patients with classical LFLG-AS undergoing SAVR, the mean transaortic gradient was the only independent mortality predictor in patients with LFLG-AS, especially if ≤25 mmHg. The absence of left ventricular FR had no prognostic impact on long-term outcomes.
经典型低流量、低跨瓣压差主动脉瓣狭窄（LFLG - AS）是主动脉瓣狭窄的晚期阶段，药物治疗预后较差，外科主动脉瓣置换术（SAVR）后手术死亡率较高。目前，关于接受SAVR的经典LFLG - AS患者的当前预后以及缺乏针对该特定AS患者亚组的可靠风险评估工具的信息较少。本研究旨在评估接受SAVR的经典LFLG - AS患者群体中的死亡预测因素。
这是一项前瞻性研究，纳入41例连续的经典LFLG - AS患者（主动脉瓣面积≤1.0 cm²，平均跨主动脉压差<40 mmHg，左心室射血分数<50%）。所有患者均接受多巴酚丁胺负荷超声心动图（DSE）、三维超声心动图和T1映射心脏磁共振成像（CMR）检查。排除假性重度主动脉瓣狭窄患者。根据平均跨主动脉压差的中位数（≤25和>25 mmHg）将患者分组。评估全因死亡率、术中死亡率、30天死亡率和1年死亡率。
所有患者均患有退行性主动脉瓣狭窄，中位年龄为66（60 - 73）岁；大多数患者为男性（83%）。欧洲心脏手术风险评估系统（EuroSCORE）II中位数为2.19%（1.5% - 4.78%），胸外科医师协会（STS）评分中位数为2.19%（1.6% - 3.99%）。在DSE检查中，73.2%的患者有血流储备（FR），即DSE期间每搏量增加≥20%，两组间无显著差异。在CMR检查中，平均跨主动脉压差>25 mmHg组的钆延迟强化心肌质量较低[2.0（0.0 - 8.9）g vs. 8.5（2.3 - 15.0）g；P = 0.034]，两组间心肌细胞外容积（ECV）和ECV指数相似。30天和1年死亡率分别为14.6%和43.8%。中位随访时间为4.1（0.3 - 5.1）年。经多因素分析校正FR后，仅平均跨主动脉压差是死亡率的独立预测因素（风险比：0.923，95%置信区间：0.864 - 0.986，P = 0.019）。平均跨主动脉压差≤25 mmHg与全因死亡率较高相关（对数秩检验P = 0.038），而FR状态对死亡率无差异（对数秩检验P = 0.114）。
在接受SAVR的经典LFLG - AS患者中，平均跨主动脉压差是LFLG - AS患者唯一的独立死亡预测因素，尤其是当平均跨主动脉压差≤25 mmHg时。左心室FR的缺失对长期预后无预后影响。
