Correlation between Acute Coronary Syndrome Classification and Multi-detector CT Characterization of Plaque

Objective To determine if multi-detector CT (MDCT) characterization of plaque is corre-lated with the classification of acute coronary syndrome (ACS). Methods Altogether 1900 patients were examined by MDCT from December 2007 to May 2009, of whom 95 patients fulfilled the criteria of ACS. Those patients were divided into the discrete plaque group (n=61) and diffuse plaque group (n=34) based on the findings in MDCT. The clinical diagnosis of ACS and CT results were analyzed, including segment stenosis score, segment involvement score, 3-vessel plaque score, left main score, calcification score, and re-modeling index. The incidences of major adverse cardiac events in follow-up period were also recorded. Results The patients of the diffuse plaque group were older than those of the discrete plaque group (P<0.0001). The diffuse plaque group presented more cases of hypertension, pe-ripheral artery disease, diabetes, and heart failure than discrete plaque group (all P<0.05). All the 5 patients with ST-segment elevation myocardial infarction were found in discrete plaque group. The segment stenosis score of the discrete plaque group was lower than that of the diffuse plaque group (5.15±3.55 vs. 14.91±5.37, P<0.001). The other four scores demonstrated significant inter-group difference as well (all P<0.05). The remodeling index of the discrete plaque group was higher (1.12±0.16 vs. 0.97±0.20, P<0.05). Follow-up data showed that major adverse cardiac events occurred more frequently in diffuse plaque group than in discrete group (29.41% vs. 11.48%, P=0.0288). Conclusions Characteristics of discrete and diffuse plaques may be significantly different among different classes of ACS. The diffuse plaque may present higher risk, correlated to higher mortality. The diagnosis of discrete and diffuse plaques by MDCT would provide a new insight into the prognosis and treatment of ACS.

Prognostic Value of Gai＇s Plaque Score and Agatston Coronary Artery Calcium Score for Functionally Significant Coronary Artery Stenosis

Background： The prognostic valtles of the coronary computed tornography angiography （CCTA） score for predicting future cardiovascular events have been previously demonstrated in numerous studies. However, few studies have used the rich information available from CCTA to detect functionally significant coronary lesions. We sought to compare the prognostic values of Gai＇s plaque score and the coronary artery calcium score tCACS） of CCTA for predicting functionally significant coronary lesions, using fractional flow reserve （FFR） as the gold standard. Methods： We retrospectively analyzed 107 visually assessed significant coronary lesions in 88 patients （mean age, 59.6 ± 10.2 years： 76.14% of males） wino underwent CCTA, invasive coronary angiography, and invasive FFR nneasurement. An FFR 〈0.80 indicated hemodynamically significant coronary stenosis. Lesions were divided into two groups using an FFR cutoffvalue of 0.80. We compared Gai＇s plaque scores and CACS between the two groups and evaluated the correlations of these scores with FFR. The statistical methods included unpaired t-test, Mann-Whitney U-test, and Spearman＇s correlation coefficients. Results： Coronary lesions with FFR 〈0.80 lind Inigtner Gai＇s scores than those with FFR 〉0.80. Gai＇s score had the strongest correlation with FFR （r= 0.48, P 〈 0.01 ） and lind a greater area under tlne curve 0.72 （95% confidence interval： 0.61 0.82： P 〈 0.01 ） than the CACS of whole arteries and a single artery. Conelusions： Botin CACS in a single artery and Gai＇s plaque score demonstrated a good capacity to assess functionally significant coronary artery stenosis when compared to the gold standard FFR. However, Gai＇s plaque score was more predictive of FFR 〈0.80. Gai＇s score cain be easily calculated in daily clinical practice and could be used when considering revascularization.

Intermittent Oxygen Inhalation with Proper Frequency Improves Overall Health Conditions and Alleviates Symptoms in a Population at High Risk of Chronic Mountain Sickness with Severe Symptoms

Background： Oxygen inhalation therapy is essential for the treatment of patients with chronic mountain sickness （CMS）, but the efficacy of oxygen inhalation for populations at high risk of CMS remains unknown. This research investigated whether oxygen inhalation therapy benefits populations at high risk of CMS. Methods： A total of 296 local residents living at an altitude of 3658 m were included; of which these were 25 diagnosed cases of CMS, 8 cases dropped out of the study, and 263 cases were included in the analysis. The subjects were divided into high-risk （180 ≤ hemoglobin （Hb） 〈210 g/L, n = 161） and low-risk （Hb 〈180 g/L, n = 102） groups, and the cases in each group were divided into severe symptom （CMS score ≥6） and mild symptom （CMS score 0-5） subgroups. Severe symptomatic population of either high- or low-risk CMS was randomly assigned to no oxygen intake group （A group） or oxygen intake 7 times/week group （D group）; mild symptomatic population of either high- or low-risk CMS was randomly assigned to no oxygen intake group （A group）, oxygen intake 2 times/week group （B group）, and 4 times/week group （C group）. The courses for oxygen intake were all 30 days. The CMS symptoms, sleep quality, physiological biomarkers, biochemical markers, etc., were recorded on the day before oxygen intake, on the 15th and 30th days of oxygen intake, and on the 15th day after terminating oxygen intake therapy. Results： A total of 263 residents were finally included in the analysis. Among these high-altitude residents, CMS symptom scores decreased for oxygen inhalation methods B, C, and D at 15 and 30 days after oxygen intake and 15 days after termination, including dyspnea, palpitation, and headache index, compared to those before oxygen intake （B group： Z = 5.604, 5.092, 5.741; C group： Z = 4.155, 4.068, 4.809; D group： Z = 6.021, 6.196, 5.331, at the 3 time points respectively; all P 〈 0.05/3 vs. before intake）. However, dyspnea/palpitation （A group： Z = 5.003, 5.428, 5.493, both P 〈 0.05/3 vs. before intake） and headache （A group： Z = 4.263, 3.890, 4.040, both P 〈 0.05/3 vs. before intake） index decreased significantly also for oxygen inhalation method A at all the 3 time points. Cyanosis index decreased significantly 30 days after oxygen intake only in the group of participants administered the D method （Z= 2.701, P = 0.007）. Tinnitus index decreased significantly in group A and D at 15 days （A group： Z = 3.377, P = 0.001, D group： Z = 3.150, P - 0.002）, 30 days after oxygen intake （A group： Z = 2.836, P = 0.005, D group： Z = 5.963, P 〈 0.0001） and 15 days after termination （A group： Z- 2.734, P = 0.006, D group： Z - 4.049, P = 0.0001）, and decreased significantly in the group B and C at 15 days after termination （B group： Z = 2.611, P = 0.009; C group： Z = 3.302, P = 0.001）. In the population at high risk of CMS with severe symptoms, oxygen intake 7 times/weeksignificantly improved total symptom scores of severe symptoms at 15 days （4 [2, 5] vs. 5.5 [4, 7], Z = 2.890, P = 0.005） and 30 days （3 [1, 5] vs. 5.5 [2, 7], Z= 3.270, P = 0.001） after oxygen intake compared to no oxygen intake. In the population at high risk of CMS with mild symptoms, compared to no oxygen intake, oxygen intake 2 or 4 times/week did not improve the total symptom scores at 15 days （2 [1, 3], 3 [1, 4] vs. 3 [1.5, 5]; 2＂2 = 2.490, P= 0.288）, and at 30 days （2 [0, 4], 2 [1, 4.5] vs. 3 [2, 5];2＂2- 3.730, P = 0.155） after oxygen intake. In the population at low risk ofCMS, oxygen intake did not significantly change the white cell count and red cell count compared to no oxygen intake, neither in the severe symptomatic population nor in the mild symptomatic population. Conclusions： Intermittent oxygen inhalation with proper frequency might alleviate symptoms in residents at high altitude by improving their overall health conditions. Administration of oxygen inhalation therapy 2-4 times/week might not benefit populations at high risk of CMS with mild CMS symptoms while administration of therapy 7 times/week might benefit those with severe symptoms. Oxygen inhalation therapy is not recommended for low-risk CMS populations.

Intravascular Ultrasound Classification of Plaque in Angiographic True Bifurcation Lesions of the Left Main Coronary Artery

Background： Accurately, characterizing plaques is critical for selecting the optimal intervention strategy for the left main coronary artery （LMCA） bifurcation. Coronary angiography cannot precisely assess the location or nature of plaques in bifurcation lesions. Few intravascular ultrasound （IVUS） classification scheme has been reported for angiographic imaging of true bifurcation lesions of the unprotected LMCA thus far. In addition, the plaque composition at the bifurcation has not been elucidated. This study aimed to detect plaque composition at LMCA bifurcation lesions by IVUS. Methods： Fifty-eight patients were recruited. The location, concentricity or eccentricity, site of maximum thickness, and composition of plaques of the distal LMCA, ostial left anterior descending （LAD） coronary artery and, left circumflex （LCX） coronary artery were assessed using IVUS and described using illustrative diagrams. Results： True bifurcation lesions of the unprotected LMCA were classified into four types： Type A, with continuous involvement from the distal LMCA to the ostial LAD and the ostial LCX with eccentric plaques; Type B, with concentric plaques at the distal LMCA, eccentric plaques at the ostial LAD, and no plaques at the LCX; Type C, with continuous involvement from the distal LMCA to the ostial LCX, with eccentric plaques, and to the ostial LAD, with eccentric plaques; and Type D, with continuous involvement from the distal LMCA to the ostial LAD, with eccentric plaques, and to the ostial LCX, with concentric plaques. The carina was involved in only 3.5% of the plaques. A total of 51.7% of the plaques at the ostium of the LAD were soft, while 44.8% and 44.6% were fibrous in the distal LMCA and in the ostial LCX, respectively. Conclusions： We classified LMCA true bifurcation lesions into four types. The carina was always free from disease. Plaques at the ostial LAD tended to be soft, whereas those at the ostial LCX and the distal LMCA tended to be fibrous.

A pilot study on diagnosis of coronary artery disease using computed tomography first-pass myocardial perfusion imaging at rest

Background:Although computed tomography coronary angiography (CTCA) can identify coronary stenosis,little data exists on the ability of multislice computed tomography (MSCT) to detect myocardial perfusion defects at rest.Methods:In 33 patients with diagnosed or suspected coronary artery disease (CAD),CTCA using retrospective electrocardiography (ECG) gating at rest and invasive coronary angiography (ICA) was performed.The 2D myocardial images were reconstructed in diastolic and systolic phases using the same raw data for CTCA.CT values of the myocardium were used as an estimate of myocardial enhancement,which were shown by color mapping.Myocardial ischemia was defined as a pattern of transient endocardial hypo-enhancement at systole and normal enhancement at diastole.The results of ICA were taken as the reference standard.Results:When a diameter reduction of more than 50% in ICA was used as diagnostic criteria of CAD,the sensitivity,specificity,positive predictive value (PPV),and negative predictive value (NPV) of CT first-pass myocardial perfusion imaging (MPI) at rest were 0.85,0.67,0.92,and 0.50 per patient,respectively,and 0.58,0.93,0.85,and 0.76 per vessel,respectively.Conclusions:CT first-pass MPI at rest could detect CAD patients,which could become a practical and convenient way to detect ischemia,consequently offering the ability for MSCT to act as a "one stop shop" for the diagnosis of CAD.