Cor Vasa 2004, 45(8):365-370
Atherosclerotic plaque rupture in patients with stable and unstable angina pectoris
- II. interní klinika, Všeobecná fakultní nemocnice a 1. lékařská fakulta Univerzity Karlovy, Praha, Česká republika
Objectives:
This study was designed to assess the occurrence of plaque rupture in patients with stable (SAP) and unstable angina pectoris (UAP) by intravascular ultrasound (IVUS).
Methods:
A total of 107 patients with only non-significant stenoses, as documented by coronary angiography, were included into the study; 62 (57.9%) with SAP and 45 (42.1%) with UAP. The group of UAP patients included those with worsening angina symptoms over the past six weeks or with angina at rest.
Results:
Overall, 145 ruptures were found in 107 patients (i. e., 1.36 ruptures per patient and artery). Plaque rupture was present in 46 SAP patients (74.2%) and in 29 UAP patients (64.4%), p = 0.28. Atherosclerotic plaque rupture was detected in 59 smokers (75.6%) and in 16 non-smokers (55.2%), p = 0.04.
Multiple ruptures (i. e., at least two ruptures per one artery) were observed in 31 SAP patients (52.5%) and in 20 patients with UAP (41.7%), p = 0.26. Diabetic patients had more multiple plaque ruptures than non-diabetic patients, 17 (68%) vs. 34 (41.5%), p = 0.02.
There is a statistically significant correlation between plaque morphology and rupture localization. Ruptures in lipid plaques were localized more often in the central part than marginal (shoulder) part of the plaque; 26 ruptures (78.2%) vs. 7 ruptures (21.8%), p < 0.001. Otherwise, ruptures in calcified plaques are localized more frequently in the marginal (shoulder) part than in the central part of the plaque, 32 ruptures (59.3%) vs. 22 ruptures (40.7%), p = 0.004.
Conclusion:
Plaque ruptures are not more frequent in UAP patients. Plaque rupture is a fairly common feature of atherosclerotic plaques but we still do not know when it triggers development of an acute coronary syndrome, and when it is only a non-risk feature of atherosclerotic plaques. We found ruptures to be more frequent in smokers. Lipid atherosclerotic plaques are prone to rupture in the central part whereas calcified atherosclerotic plaques are more likely to rupture in their marginal (shoulder) part.
Keywords: Intravascular ultrasound; Rupture; Atherosclerotic plaque; Acute coronary syndrome
Published: August 1, 2004 Show citation