Pizzulli L, Yang A, Martin J F, Lüderitz B
Department of Cardiology, University of Bonn, Germany.
Eur Heart J. 1998 Jan;19(1):80-4. doi: 10.1053/euhj.1997.0747.
An increase in platelet aggregability is associated with unstable angina and myocardial infarction. Platelet size and activity correlate and mean platelet volume was found to be increased before acute myocardial infarction. We measured the mean platelet volume and platelet count in patients with stable angina, unstable angina and non-cardiac chest pain.
We studied 981 patients (734 men; 247 women) defined clinically as stable angina (n = 688), unstable angina (n = 108) and unstable angina requiring immediate angioplasty (n = 52). After coronary angiography the patients were subdivided into single (n = 269), double (n = 304) and triple-vessel disease (n = 311) and the control group of non-cardiac chest pain (n = 97). There was no significant difference in platelet count between the control group and patients with 1, 2, or 3-vessel disease. However, the platelet size in patients with coronary artery disease was significantly larger (single: 8.7 +/- 1.19 fl; double: 8.7 +/- 1.12 fl; triple-vessel disease: 8.8 +/- 1.18 fl) than the control group (8.2 +/- 0.95 fl) (P < 0.01). Patients with stable angina similarly had no, significant difference in platelet count compared to the control group but did have a significantly increased mean platelet volume (8.7 +/- 1.13; P < 0.01). In contrast, patients with unstable angina had a decreased platelet count (245 +/- 56 x 10/l) compared to either stable angina (262 +/- 62 x 10/l; P < 0.05) or the control group (261 +/- 58 x 10/l; P < 0.05); furthermore, the mean platelet volume (9.4 +/- 1.23 fl) was significantly greater than for stable angina (P < 0.01). Patients with unstable angina requiring immediate PTCA had an even lower platelet count (231 +/- 55 x 10/l) and higher mean platelet volume (10.4 +/- 1.03 fl) (P < 0.01) than the rest of the population with unstable angina.
In stable angina the platelet count is unchanged compared to patients with normal coronary arteries but the platelet size is increased. However, in unstable angina there is a decrease in platelet count and an even larger increase in platelet size. We interpret this as meaning that unstable angina might be associated or preceded by an increase in platelet destruction rate that is not completely compensated for by an increase in platelet production rate. The large, more reactive platelets might be causally related to an ongoing coronary artery obstruction in unstable angina.
血小板聚集性增加与不稳定型心绞痛及心肌梗死相关。血小板大小与活性相关，且发现急性心肌梗死前平均血小板体积增加。我们测定了稳定型心绞痛、不稳定型心绞痛及非心源性胸痛患者的平均血小板体积和血小板计数。
我们研究了981例患者（734例男性；247例女性），临床诊断为稳定型心绞痛（n = 688）、不稳定型心绞痛（n = 108）及需立即行血管成形术的不稳定型心绞痛（n = 52）。冠状动脉造影后，患者被分为单支血管病变（n = 269）、双支血管病变（n = 304）和三支血管病变（n = 311）组以及非心源性胸痛对照组（n = 97）。对照组与单支、双支或三支血管病变患者的血小板计数无显著差异。然而，冠心病患者的血小板大小显著大于对照组（单支血管病变：8.7±1.19 fl；双支血管病变：8.7±1.12 fl；三支血管病变：8.8±1.18 fl）（对照组：8.2±0.95 fl）（P < 0.01）。稳定型心绞痛患者与对照组相比血小板计数同样无显著差异，但平均血小板体积显著增加（8.7±1.13；P < 0.01）。相比之下，不稳定型心绞痛患者的血小板计数低于稳定型心绞痛患者（245±56×10⁹/L）（P < 0.05）或对照组（261±58×10⁹/L）（P < 0.05）；此外，平均血小板体积（9.4±1.23 fl）显著大于稳定型心绞痛患者（P < 0.01）。需立即行PTCA的不稳定型心绞痛患者的血小板计数更低（231±55×10⁹/L），平均血小板体积更高（10.4±1.03 fl）（P < 0.01），高于其他不稳定型心绞痛患者。
与冠状动脉正常的患者相比，稳定型心绞痛患者的血小板计数无变化，但血小板大小增加。然而，在不稳定型心绞痛中，血小板计数减少，血小板大小增加更为明显。我们将此解释为不稳定型心绞痛可能与血小板破坏率增加相关或在其之前发生，而血小板生成率增加并未完全补偿这一破坏率增加。较大、更具反应性的血小板可能与不稳定型心绞痛中持续存在的冠状动脉阻塞存在因果关系。
