Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
Federal University of Espirito Santo, Vitoria, Brazil.
Chest. 2011 Jul;140(1):62-67. doi: 10.1378/chest.10-1722. Epub 2011 Feb 24.
Impaired brachial flow-mediated dilation (FMD) is associated with risk for subsequent cardiovascular events in patients after myocardial infarction (MI). These patients often have obstructive sleep apnea (OSA). We tested the hypothesis that patients with OSA post MI will exhibit more severe impairment in FMD.
We studied 64 patients with MI admitted to our hospital. OSA was determined using polysomnography. FMD was measured using high-resolution ultrasonography, with researchers blind to the OSA diagnosis.
The mean age was 60 ± 11 years, and the mean BMI was 29 (26, 32 kg/m(2)), 84% of patients were men, 39% had moderate to severe OSA (apnea-hypopnea index [AHI] > 15), and 31% of the patients had mild OSA (5 ≤ AHI < 15). FMD was severely impaired in patients with moderate to severe OSA (0.8% ± 0.7%) as compared with patients without OSA (4.7% ± 0.8%, P = .001) and with mild OSA (3.9% ± 0.8%, P = .015). Linear regression showed that FMD was associated with log nocturnal nadir oxygen saturation (minSaO(2)) (β = 31.17, P = .0001), age (β = -0.11, P = .006). MinSaO(2) was an independent predictor of FMD after adjustment for possible confounders (β = 26.15, P = .001).
FMD is severely impaired in patients with moderate to severe OSA post MI, which may be partially related to nocturnal hypoxemia. Patients with OSA may, therefore, be at higher risk for subsequent cardiovascular events after an MI. Identifying and treating OSA may have important implications in the long-term prognosis of patients post MI. Further studies are necessary to determine if the presence of OSA would affect the long-term occurrence of cardiovascular events after an MI.
在心肌梗死（MI）后患者中，肱动脉血流介导的扩张（FMD）受损与随后发生心血管事件的风险相关。这些患者常有阻塞性睡眠呼吸暂停（OSA）。我们验证了如下假设，即患有 OSA 的 MI 后患者会表现出更严重的 FMD 受损。
我们研究了我院收治的 64 例 MI 患者。通过多导睡眠图确定 OSA。使用高分辨率超声测量 FMD，研究者对 OSA 诊断不知情。
患者平均年龄为 60 ± 11 岁，平均 BMI 为 29（26，32 kg/m2），84%的患者为男性，39%患有中重度 OSA（呼吸暂停低通气指数[AHI] > 15），31%的患者患有轻度 OSA（5 ≤ AHI < 15）。与无 OSA 的患者（4.7% ± 0.8%，P =.001）和轻度 OSA 的患者（3.9% ± 0.8%，P =.015）相比，中重度 OSA 患者的 FMD 严重受损（0.8% ± 0.7%）。线性回归显示，FMD 与夜间最小氧饱和度（minSaO2）的对数（β = 31.17，P =.0001）和年龄（β = -0.11，P =.006）相关。校正可能的混杂因素后，minSaO2 是 FMD 的独立预测因子（β = 26.15，P =.001）。
MI 后中重度 OSA 患者的 FMD 严重受损，这可能部分与夜间低氧血症有关。因此，MI 后 OSA 患者发生心血管事件的风险可能更高。在 MI 后患者的长期预后中，识别和治疗 OSA 可能具有重要意义。需要进一步的研究来确定 OSA 的存在是否会影响 MI 后心血管事件的长期发生。
