PATIENTS WITH CHRONIC SEVERE AORTIC REGURGITATION

慢性严重主动脉瓣反流患者

• 批准号: 6418997
• 负责人: JULIO PANZA
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6418997
• 关键词: aortic valve insufficiency; chronic disease /disorder; clinical research; diagnosis design /evaluation; dobutamine; echocardiography; heart contraction; heart disorder diagnosis; heart pharmacology; heart valve transplantation; human subject; ventricular hypertrophy

In asymptomatic patients with chronic severe aortic regurgitation (AR), the timing of valve replacement (AVR) is routinely determined by serial evaluation of resting left ventricular (LV) size and function. However, early signs of myocardial dysfunction may not be detected with currently used methods. The purpose of this study was to investigate whether the myocardial response to inotropic stimulation at the initial evaluation is related to progressive LV dilation, LV dysfunction, or the development of symptoms during follow-up which would, in turn, prompt the recommendation for AVR. To this end, we studied 28 patients (23 men and 5 women; age 45+/-14 years) with chronic severe AR who, at the time of entry into the study, were asymptomatic, did not have severe LV dilation (LV end-diastolic [LVD]/ end-systolic [LVS] dimensions < 75/55 mm), and had normal LV function (resting ejection fraction [EF] > 45%). Upon entry into the study, patients underwent echocardiography during incremental infusion of dobutamine from 5 to 20 mcg/kg/min. At each stage, systolic thickening (ST) was measured in the short-axis view at the papillary muscle level using the centerwall method. Serial routine echocardiograms, radionuclide ventriculograms, and exercise testing were performed every 6-12 months to determine the need for AVR, irrespective of the results of the initial dobutamine echocardiogram. After a mean follow-up of 71 months (range 34 to 90), 18 patients (Group 1) remained asymptomatic without progressive LV dilation or dysfunction. Of the remaining 10 patients (Group 2), 9 required AVR and 1 patient died, an average of 40 months (range 1 to 83) after the dobutamine echocardiogram (attrition rate 6% per year). At initial evaluation, there were no significant differences in resting LVD, LVS, EF or exercise tolerance (ET) between the two groups; however, patients in Group 2 had significantly depressed response to inotropic stimulation with dobutamine: LVD(mm) 64+/-6 vs 67+/-6 (p=0.16); LVS(mm) 40+/-7 vs 44+/-6 (p=0.12); EF(%) 58+/-9 vs 56+/-10 (p=0.51); ET(min) 14.2+/-4.0 vs 11.9+/-6.6 (p=0.33); ST with dobutamine(mm) 7.1+/-1.2 vs 5.3+/-0.9 (p= 0.003) (Group 1 vs Group 2, respectively, for all comparisons. Hence, in asymptomatic patients with chronic severe AR, a diminished contractile reserve is associated with development of symptoms, progressive LV dilation or dysfunction during follow-up. Assessment of the myocardial response to inotropic stimulation may therefore unmask early signs of myocardial dysfunction and thus aid in the serial evaluation of these patients.

在患有慢性重度主动脉瓣返流（AR）的无症状患者中，瓣膜置换术（AVR）的时机通常通过对静息左心室（LV）大小和功能的系列评价来确定。 然而，目前使用的方法可能无法检测到心肌功能障碍的早期体征。 本研究的目的是研究初始评价时对变力性刺激的心肌反应是否与进行性LV扩张、LV功能障碍或随访期间症状的发展相关，这反过来又会促使推荐进行AVR。 为此，我们研究了28例慢性重度AR患者（23例男性和5例女性;年龄45 ± 14岁），这些患者在进入研究时无症状，无重度LV扩张（LV舒张末期[LVD]/收缩末期[LVS]尺寸< 75/55 mm），LV功能正常（静息射血分数[EF] > 45%）。 进入研究后，患者在多巴酚丁胺5至20 mcg/kg/min的增量输注期间接受超声心动图检查。在每个阶段，使用中心壁方法在乳头肌水平的短轴视图中测量收缩期增厚（ST）。 每6-12个月进行一系列常规超声心动图、放射性核素心室造影和运动试验，以确定是否需要AVR，而不考虑初始多巴酚丁胺超声心动图的结果。 平均随访71个月（范围34 - 90）后，18例患者（第1组）仍无症状，无进行性LV扩张或功能障碍。 在其余10例患者（第2组）中，9例需要AVR，1例患者死亡，平均为多巴酚丁胺超声心动图后40个月（范围1 - 83）（每年损耗率6%）。 在初始评估时，两组之间的静息LVD、LVS、EF或运动耐量（ET）无显著差异;然而，第2组患者对多巴酚丁胺正性肌力刺激的反应显著降低：LVD（mm）64+/-6 vs 67+/-6（p=0.16）; LVS（mm）40+/-7 vs 44+/-6（p=0.12）; EF（%）58+/-9 vs 56+/-10（p=0.51）; ET（min）14.2+/-4.0 vs 11.9+/-6.6（p=0.33）;多巴酚丁胺ST（mm）7.1+/-1.2 vs 5.3+/-0.9（p= 0.003）（所有比较分别为第1组vs第2组。 因此，在慢性重度AR的无症状患者中，收缩储备减少与随访期间症状的发展、进行性LV扩张或功能障碍相关。 因此，评估心肌对正性肌力刺激的反应可能会发现心肌功能障碍的早期体征，从而有助于对这些患者进行系列评价。