School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Circ Cardiovasc Imaging. 2013 Nov;6(6):1001-8. doi: 10.1161/CIRCIMAGING.112.000328. Epub 2013 Oct 4.
Net atrioventricular compliance (Cn) has been reported to be an important determinant of pulmonary hypertension in mitral stenosis (MS). We hypothesized that it may be useful in assessing prognosis because Cn reflects hemodynamic consequences of MS. To date, limited data with an assumed Cn cutoff have indicated the need for larger prospective studies. This prospective study was designed to determine the impact of Cn on clinical outcome and its contribution to pulmonary pressure in MS. In addition, we aimed to identify a cutoff value of Cn for outcome prediction in this setting.
A total of 128 patients with rheumatic MS without other significant valve disease were prospectively enrolled. Comprehensive echocardiography was performed and Doppler-derived Cn estimated using a previously validated equation. The end point was either mitral valve intervention or death. Cn was an important predictor of pulmonary pressure, regardless of classic measures of MS severity. During a median follow-up of 22 months, the end point was reached in 45 patients (35%). Baseline Cn predicted outcome, adding prognostic information beyond that provided by mitral valve area and functional status. Cn ≤4 mL/mm Hg best predicted unfavorable outcome in derivation and validation sets. A subgroup analysis including only initially asymptomatic patients with moderate to severe MS without initial indication for intervention (40.6% of total) demonstrated that baseline Cn predicted subsequent adverse outcome even after adjustment for classic measures of hemodynamic MS severity (hazard ratio, 0.33; 95% confidence interval, 0.14-0.79; P=0.013).
Cn contributes to pulmonary hypertension beyond stenosis severity itself. In a wide spectrum of MS severity, Cn is a powerful predictor of adverse outcome, adding prognostic value to clinical data and mitral valve area. Importantly, baseline Cn predicts a progressive course with subsequent need for intervention in initially asymptomatic patients. Cn assessment therefore has potential value for clinical risk stratification and monitoring in MS patients.
已有研究报道，房室顺应性（Cn）是二尖瓣狭窄（MS）患者发生肺动脉高压的重要决定因素。我们假设，Cn 可能有助于评估预后，因为它反映了 MS 的血流动力学后果。迄今为止，根据有限的研究数据，假设存在 Cn 切点，这表明需要更大规模的前瞻性研究。本前瞻性研究旨在确定 Cn 对临床结局的影响及其在 MS 患者中对肺动脉压的影响。此外，我们旨在确定在此环境下用于预测结局的 Cn 切点值。
共前瞻性纳入了 128 例无其他严重瓣膜疾病的风湿性 MS 患者。进行了全面的超声心动图检查，并使用先前验证的方程计算了多普勒衍生的 Cn。终点是二尖瓣瓣膜干预或死亡。Cn 是肺动脉压的重要预测因子，无论 MS 严重程度的经典测量如何。在中位随访 22 个月期间，45 例患者（35%）达到终点。Cn 基线值可预测结局，除了提供二尖瓣瓣口面积和功能状态之外，还提供了预后信息。在推导和验证组中，Cn≤4 mL/mm Hg 可最佳预测不良结局。一项包括仅初始无症状且具有中度至重度 MS 但无初始干预指征的患者的亚组分析（占总人数的 40.6%）表明，即使在校正 MS 血流动力学严重程度的经典测量后，Cn 基线值仍可预测随后发生不良结局（危险比，0.33；95%置信区间，0.14-0.79；P=0.013）。
Cn 除了狭窄严重程度本身之外，还会导致肺动脉高压。在广泛的 MS 严重程度范围内，Cn 是不良结局的有力预测因子，为临床数据和二尖瓣瓣口面积提供了预后价值。重要的是，Cn 基线值可预测初始无症状患者的病情进展，随后需要进行干预。因此，Cn 评估对于 MS 患者的临床风险分层和监测具有潜在价值。
