AIMS  The non-invasive assessment of left ventricular (LV) diastolic function and filling pressure in hypertrophic cardiomyopathy (HCM) is still an open issue. Pulmonary blood volume index (PBVI) by cardiovascular magnetic resonance (CMR) has been proposed as a quantitative biomarker of haemodynamic congestion. We aimed to assess the diagnostic accuracy of PBVI for left atrial pressure (LAP) estimation in patients with HCM. METHODS AND RESULTS  We retrospectively identified 69 consecutive HCM outpatients (age 58 ± 11 years; 83% men) who underwent both transthoracic echocardiography (TTE) and CMR. Guideline-based detection of LV diastolic dysfunction was assessed by TTE, blinded to CMR results. PBVI was calculated as the product of right ventricular stroke volume index and the number of cardiac cycles for a bolus of gadolinium to pass through the pulmonary circulation as assessed by first-pass perfusion imaging. Compared to patients with normal LAP, patients with increased LAP showed significantly larger PBVI (463 ± 127 vs. 310 ± 86 mL/m2, P < 0.001). PBVI increased progressively with worsening New York Heart Association functional class and echocardiographic stages of diastolic dysfunction (P < 0.001 for both). At the best cut-off point of 413 mL/m2, PBVI yielded good diagnostic accuracy for the diagnosis of LV diastolic dysfunction with increased LAP [C-statistic = 0.83; 95% confidence interval (CI): 0.73-0.94]. At multivariable logistic regression analysis, PBVI was an independent predictor of increased LAP (odds ratio per 10% increase: 1.97, 95% CI: 1.06-3.68; P = 0.03). CONCLUSION  PBVI is a promising CMR application for assessment of diastolic function and LAP in patients with HCM and may serve as a quantitative marker for detection, grading, and monitoring of haemodynamic congestion.

中文翻译：

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肺血容量指数作为肥厚型心肌病血流动力学充血的定量生物标志物。

目的 肥厚型心肌病 (HCM) 中左心室 (LV) 舒张功能和充盈压的无创评估仍然是一个悬而未决的问题。心血管磁共振 (CMR) 的肺血容量指数 (PBVI) 已被提议作为血流动力学充血的定量生物标志物。我们旨在评估 PBVI 对 HCM 患者左心房压力 (LAP) 估计的诊断准确性。方法和结果 我们回顾性地确定了 69 名连续接受经胸超声心动图 (TTE) 和 CMR 的 HCM 门诊患者（年龄 58 ± 11 岁；83% 为男性）。通过 TTE 评估基于指南的 LV 舒张功能障碍检测，对 CMR 结果不知情。PBVI 计算为右心室每搏输出量指数和一团钆通过肺循环的心动周期数的乘积，通过首过灌注成像评估。与 LAP 正常的患者相比，LAP 升高的患者的 PBVI 显着增加（463 ± 127 vs. 310 ± 86 mL/m2，P < 0.001）。PBVI 随着纽约心脏协会功能分级和舒张功能障碍超声心动图分期的恶化而逐渐增加（两者的 P < 0.001）。在 413 mL/m2 的最佳截断点时，PBVI 对 LAP 增加的 LV 舒张功能障碍的诊断具有良好的诊断准确性 [C 统计量 = 0.83；95% 置信区间 (CI)：0.73-0.94]。在多变量逻辑回归分析中，PBVI 是 LAP 增加的独立预测因子（每增加 10% 的优势比：1.97，95% CI：1.06-3.68；P = 0.03）。结论 PBVI 是一种很有前景的 CMR 应用，可用于评估 HCM 患者的舒张功能和 LAP，并可作为血流动力学充血检测、分级和监测的定量标志物。