Spotty calcification typifies the culprit plaque in patients with acute myocardial infarction - An intravascular ultrasound study
ABSTRACT Calcification is a common finding in human coronary arteries; however, the relationship between calcification patterns, plaque morphology, and patterns of remodeling of culprit lesions in a comparison of patients with acute coronary syndromes (ACS) and those with stable conditions has not been documented.
Preinterventional intravascular ultrasound (IVUS) images of 178 patients were studied, 61 with acute myocardial infarction (AMI), 70 with unstable angina pectoris (UAP), and 47 with stable angina pectoris (SAP). The frequency of calcium deposits within an arc of less than 90 degrees for all calcium deposits was significantly different in culprit lesions of patients with AMI, UAP, and SAP (P<0.0001). Moreover, the average number of calcium deposits within an arc of <90 degrees per patient was significantly higher in AMI than in SAP (P<0.0005; mean+/-SD, AMI 1.4+/-1.3, SAP 0.5+/-0.8). Conversely, calcium deposits were significantly longer in SAP patients (P<0.0001; mean+/-SD, AMI 2.2+/-1.6, UAP 1.9+/-1.8, and SAP 4.3+/-3.2 mm). In AMI patients, the typical pattern was spotty calcification, associated with a fibrofatty plaque and positive remodeling. In ACS patients showing negative remodeling, no calcification was the most frequent observation. Conversely, SAP patients had the highest frequency of extensive calcification.
Our observations show that IVUS allows the identification of vulnerable plaques in coronary arteries, not only by identifying a fibrofatty plaque and positive remodeling, but also by identifying a spotty pattern of calcification.
SourceAvailable from: Michael J Blaha[Show abstract] [Hide abstract]
ABSTRACT: Although the traditional Agatston coronary artery calcium (CAC) score is a powerful predictor of mortality, it is unknown if the regional distribution of CAC further improves cardiovascular risk prediction. We retrospectively studied 23,058 patients referred for Agatston CAC scoring, of whom 61% had CAC (n = 14,084). CAC distribution was defined as the number of vessels with CAC (0 to 4, including left main). For multivessel CAC, "diffuse" CAC was defined by decreasing percentage of CAC in the single most affected vessel and by ≤75% total Agatston CAC score in the most calcified vessel. All-cause mortality was ascertained through the social security death index. The mean age was 55 ± 11 years, with 69% men. There were 584 deaths (2.5%) over 6.6 ± 1.7 years. Considerable heterogeneity existed between the Agatston CAC score group and the number of vessels with CAC. In each CAC group, increasing number of vessels with CAC was associated with an increased mortality rate. After adjusting for age, gender, Agatston CAC score, and cardiovascular risk factors, increasing number of vessels with CAC was associated with higher mortality risk compared with single-vessel CAC (2-vessel: HR 1.61 [95% CI 1.14 to 2.25], 3-vessel: 1.99 [1.44 to 2.77], and 4-vessel: 2.22 [1.53 to 3.23]). "Diffuse" CAC was associated with a higher mortality rate in the CAC 101 to 400 and >400 groups. Left main CAC was associated with increased mortality risk. In conclusion, increasing number of vessels with CAC and left main CAC predict increased all-cause mortality and improve the prognostic power of the traditional Agatston CAC score. Copyright © 2015 Elsevier Inc. All rights reserved.
[Show abstract] [Hide abstract]
ABSTRACT: Spotty calcification is a morphological characteristic of a vulnerable plaque phenotype. While this calcium pattern is considered an active process, promoted by inflammation, it is unknown whether spotty calcification associates with development of microstructures observed in vulnerable plaques. As frequency-domain optical coherence tomography (FD-OCT) enables visualization of microstructures associated with plaque vulnerability, we investigated the association between spotty calcification and plaque microstructures by using FD-OCT. A total of 300 patients with stable coronary artery disease (CAD), having clinical indication for percutaneous coronary intervention (PCI), were analyzed. Totally 280 non-culprit lipid plaques within the target vessel requiring PCI were evaluated by FD-OCT. Spotty calcification was defined as a presence of lesion <4 mm in length, containing an arc of calcification <90° on FD-OCT. Plaque microstructures were compared in non-culprit lipid-rich plaques with and without spotty calcification. Spotty calcification was observed in 39.6% of non-culprit lipid-rich plaques, with 30.6% of these plaques demonstrating multiple spotty calcifications. Plaques containing spotty calcification exhibited a greater lipid index (= averaged lipid arc × lipid length); 1,511.8±1,522.3 vs. 815.2±1,040.3 mm°, P<0.0001), thinner fibrous caps (89.0±31.6 vs. 136.5±32.5 µm, P=0.002) and a higher prevalence of microchannels (45.9% vs. 17.7%, P=0.007). A significant association was observed between the number of spotty calcifications per plaque and fibrous cap thickness (r=-0.40, P=0.006). Increased number of spotty calcification was also associated with a higher prevalence of microchannel within plaques (P=0.01). In patients with stable CAD requiring PCI, the presence of spotty calcification imaged by FD-OCT was associated with features of greater plaque vulnerability.
[Show abstract] [Hide abstract]
ABSTRACT: Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately characterising the calcification coupled with the associated mechanical plaque properties is needed to better understand the impact of calcification on the mechanical behaviour of the plaque during minimally invasive treatments. This study proposes a comparison of biochemical and structural characterisation methods of the calcification in carotid plaque specimens to identify plaque mechanical behaviour.BioMedical Engineering OnLine 01/2015; 14 Suppl 1:S5. DOI:10.1186/1475-925X-14-S1-S5 · 1.75 Impact Factor