Graf S, Khorsand A, Gwechenberger M, Schütz M, Kletter K, Sochor H, Dudczak R, Maurer G, Pirich C, Porenta G, Zehetgruber M
Department of Cardiology, Medical University of Vienna, Vienna, Austria.
Eur J Clin Invest. 2006 May;36(5):326-32. doi: 10.1111/j.1365-2362.2006.01635.x.
Approximately 10-30% of patients with typical chest pain present normal epicardial coronaries. In a proportion of these patients, angina is attributed to microvascular dysfunction. Previous studies investigating whether angina is the result of abnormal resting or stress perfusion are controversial but limited by varying inclusion criteria. Therefore, we investigated whether microvascular dysfunction in these patients is associated with perfusion abnormalities at rest or at stress.
In 58 patients (39 female, 19 male, mean age 58+/-10 years) with angina and normal angiogram as well as 10 control patients with atypical chest pain and normal coronaries (six female, four male, mean age 53+/-11 years) myocardial blood flow (MBF) was measured at rest and under dipyridamole using 13N-ammonia PET. Resting MBF and coronary flow reserve (CFR) as the ratio of hyperaemic to resting MBF were corrected for rate-pressure-product (RPP): normalized resting MBF (MBFn)=MBFx10,000/RPP and CFRn=CFRxRPP/10,000.
Sixteen/58 patients had a normal CFRn (=2.5; group I; CFRn: 3.1+/-0.88); the same as the controls (CFRn: 3.3+/-0.74). Forty-two/58 patients presented a reduced CFRn (group II; CFRn: 1.78+/-0.57). Group II had both a higher MBFn (group II: 1.30+/-0.33 vs. Group I: 1.03+/-0.26; P<0.05 and vs. controls: 1.07+/-0.19; P<0.01) and a lower hyperaemic MBF (group II: 2.25+/-0.76 mL g-1 min-1 vs. Group I: 3.07+/-0.78 mL g-1 min-1; P<0.001 and vs. controls: 3.41+/-0.94 mL g-1 min-1; P<0.0001).
Impaired CFRn in patients with typical angina and normal angiogram is owing to both an increased resting and reduced hyperaemic MBF. Therefore, PET represents a prerequisite for further studies to optimize treatment in individuals with anginal pain and normal coronary angiogram.
约10%-30%有典型胸痛症状的患者其心外膜冠状动脉正常。在这些患者中，一部分心绞痛归因于微血管功能障碍。既往关于心绞痛是否由静息或负荷灌注异常所致的研究存在争议，且受纳入标准各异的限制。因此，我们研究了这些患者的微血管功能障碍是否与静息或负荷时的灌注异常相关。
对58例（39例女性，19例男性，平均年龄58±10岁）有胸痛症状且血管造影正常的患者以及10例有非典型胸痛症状且冠状动脉正常的对照患者（6例女性，4例男性，平均年龄53±11岁），使用13N-氨PET在静息和双嘧达莫负荷状态下测量心肌血流量（MBF）。静息MBF和冠状动脉血流储备（CFR，即充血时MBF与静息MBF之比）经心率-血压乘积（RPP）校正：静息MBF标准化值（MBFn）=MBF×10,000/RPP，CFR标准化值（CFRn）=CFR×RPP/10,000。
16/58例患者CFRn正常（=2.5；第一组；CFRn：3.1±0.88），与对照组相同（CFRn：3.3±0.74）。42/58例患者CFRn降低（第二组；CFRn：1.78±0.57）。第二组的静息MBF标准化值更高（第二组：1.30±0.33 vs. 第一组：1.03±0.26；P<0.05，与对照组相比：1.07±0.19；P<0.01），充血时MBF更低（第二组：2.25±0.76 mL g-1 min-1 vs. 第一组：3.07±0.78 mL g-1 min-1；P<0.001，与对照组相比：3.41±0.94 mL g-1 min-1；P<0.0001）。
典型心绞痛且血管造影正常的患者CFRn受损是由于静息MBF增加和充血时MBF降低。因此，PET是进一步研究优化有胸痛症状且冠状动脉造影正常个体治疗方案的前提条件。
