PET/CT Assessment of Symptomatic Individuals with Obstructive and Nonobstructive Hypertrophic Cardiomyopathy
PET/CT Assessment of Symptomatic Individuals with Obstructive and Nonobstructive Hypertrophic Cardiomyopathy
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DOI：
10.2967/jnumed.111.096156
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发表时间：
2012-03-01
影响因子：
9.3
通讯作者：
Bengel, Frank M.
中科院分区：
文献类型：
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作者：
Bravo, Paco E.;Pinheiro, Aurelio;Bengel, Frank M.
梗阻性肥厚型心肌病 (HCM) 患者左心室流出道梯度 (LVOTG) 升高，且预后似乎比非梗阻性肥厚型心肌病 (HCM) 患者更差。本研究的目的是评估梗阻患者与非梗阻性 HCM 患者的微血管功能 PET 参数是否存在显着差异。方法：对 33 例有症状的 HCM 患者在休息和双嘧达莫负荷（峰值）时进行 PET 评估，以评估局部心肌灌注（rMP）、左心室射血分数（LVEF）、心肌血流量（MBF）和心肌血流储备（MFR）。通过超声心动图测量心肌壁厚度和 LVOTG。患者被分为以下 3 组：非梗阻性组（静息时 LVOTG，30 mm Hg，亚硝酸戊酯激发试验后）、梗阻性组（静息时 LVOTG >= 30 mm Hg，激发时）和潜伏性 HCM（LVOTG，静息时 30 mm Hg，激发时 >= 30 mm Hg）。结果：11 名患者被归类为非梗阻性（第 1 组），12 名患者被归类为梗阻性（第 2 组），10 名患者被归类为潜伏性 HCM（第 3 组）。除年龄（第 1 组为 42 +/- 18 岁，第 2 组为 58 +/- 7 岁，第 3 组为 58 +/- 12 岁；P = 0.01）外，所有 3 组均具有相似的基线特征，包括最大壁厚（第 1 组为 2.3 +/- 0.5 cm，第 2 组为 2.2 +/- 0.4 cm，第 2 组为 2.1 +/- 0.7 cm） 3；P = 0.7）。在峰值流量期间，第 1 组和第 2 组中的大多数患者（第 3 组中较少）表现出 rMP 缺陷（第 1 组为 73%，第 2 组为 100%，第 3 组为 40%；P = 0.007），并且 LVEF 下降（第 1 组为 73%，第 2 组为 92%，第 3 组为 50%；P = 0.09）。峰值 MBF（第 1 组为 1.58 +/- 0.49 mL/min/g，第 2 组为 1.72 +/- 0.46 mL/min/g，第 3 组为 1.97 +/- 0.32 mL/min/g；P = 0.14）和 MFR（第 1 组为 1.62 +/- 0.57，第 2 组为 1.90 +/- 0.31，以及第 3 组为 2.27 +/- 0.51；P = 0.01）在非阻塞性组中较低，在潜在 HCM 组中较高。 LVOTG 与任何血流动力学没有显着相关性。在多元回归分析中，最大壁厚是峰值 MBF（β = -0.45，P = 0.003）和 MFR（β = -0.63，P = 0.0001）降低的唯一显着预测因子。结论：在我们的研究中，最大壁厚度被认为是双嘧达莫引起的充血和血流储备受损的最强预测因素，而流出道阻塞并不是一个独立的决定因素。
Patients with obstructive hypertrophic cardiomyopathy (HCM) exhibit elevated left ventricular outflow tract gradients (LVOTGs) and appear to have a worse prognosis than those with nonobstructive HCM. The aim of this study was to evaluate whether patients with obstruction, compared with nonobstructive HCM, demonstrate significant differences in PET parameters of microvascular function. Methods: PET was performed in 33 symptomatic HCM patients at rest and during dipyridamole stress (peak) for the assessment of regional myocardial perfusion (rMP), left ventricular ejection fraction (LVEF), myocardial blood flow (MBF), and myocardial flow reserve (MFR). Myocardial wall thickness and LVOTG were measured with an echocardiogram. Patients were divided into the following 3 groups: nonobstructive (LVOTG, 30 mm Hg at rest and after provocation test with amyl nitrite), obstructive (LVOTG >= 30 mm Hg at rest and with provocation), and latent HCM (LVOTG, 30 at rest but >= 30 mm Hg with provocation). Results: Eleven patients were classified as nonobstructive (group 1), 12 as obstructive (group 2), and 10 as latent HCM (group 3). Except for age (42 +/- 18 y for group 1, 58 +/- 7 y for group 2, and 58 +/- 12 y for group 3; P = 0.01), all 3 groups had similar baseline characteristics, including maximal wall thickness (2.3 +/- 0.5 cm for group 1, 2.2 +/- 0.4 cm for group 2, and 2.1 +/- 0.7 cm for group 3; P = 0.7). During peak flow, most patients in groups 1 and 2, but fewer in group 3, exhibited rMP defects (73% for group 1, 100% for group 2, and 40% for group 3; P = 0.007) and a drop in LVEF (73% for group 1, 92% for group 2, and 50% for group 3; P = 0.09). Peak MBF (1.58 +/- 0.49 mL/min/g for group 1, 1.72 +/- 0.46 mL/min/g for group 2, and 1.97 +/- 0.32 mL/min/g for group 3; P = 0.14) and MFR (1.62 +/- 0.57 for group 1, 1.90 +/- 0.31 for group 2, and 2.27 +/- 0.51 for group 3; P = 0.01) were lower in the nonobstructive and higher in the latent HCM group. LVOTGs demonstrated no significant correlation with any flow dynamics. In a multivariate regression analysis, maximal wall thickness was the only significant predictor for reduced peak MBF (beta = -0.45, P = 0.003) and MFR (beta = -0.63, P = 0.0001). Conclusion: Maximal wall thickness was identified as the strongest predictor of impaired dipyridamole-induced hyperemia and flow reserve in our study, whereas outflow tract obstruction was not an independent determinant.