AimsStent underexpansion and malapposition are associated with adverse outcomes following percutaneous coronary intervention, but detection and treatment can be challenging in the presence of ...extensive coronary artery calcification. Frequency domain optical coherence tomography (FD-OCT) is a novel intravascular imaging technique with greater spatial resolution than intravascular ultrasound (IVUS) but its role in the presence of extensive coronary calcification remains unclear. We sought to determine the utility of FD-OCT compared to IVUS imaging to guide percutaneous coronary intervention in patients with severe calcific coronary artery disease.Methods18 matched IVUS and FD-OCT examinations were evaluated following coronary stent implantation in 12 patients (10 male; mean age 70±7 years) undergoing rotational atherectomy for symptomatic calcific coronary artery disease.ResultsIn-stent luminal areas were smaller (minimum in-stent area 6.77±2.18 vs 7.19±2.62 mm2, p<0.05), while reference lumen dimensions were similar with FD-OCT compared with IVUS. Stent malapposition was detected in all patients by FD-OCT and in 10 patients by IVUS. The extent of stent malapposition detected was greater (20% vs 6%, p<0.001) with FD-OCT compared to IVUS. Postdilation increased the in-stent luminal area (minimum in-stent area: 8.15±1.90 vs 7.30±1.62 mm2, p<0.05) and reduced the extent of stent malapposition (19% vs 34%, p<0.005) when assessed by FD-OCT, but not IVUS.ConclusionsAcute stent malapposition occurs frequently in patients with calcific coronary disease undergoing rotational atherectomy and stent implantation. In the presence of extensive coronary artery calcification, FD-OCT affords enhanced stent visualisation and detection of malapposition, facilitating improved postdilation stent apposition and minimal luminal areas.Trial Registration numberNCT02065102.
OBJECTIVEArterial stiffness is an emerging major risk factor for cardiovascular morbidity and mortality. The aim of the present study was to assess if coronary artery plaque load correlates with ...non-invasive measures of arterial stiffness.
DESIGNProspective investigational study.
SETTINGTertiary university hospital centre.
PATIENTSPatients undergoing elective diagnostic coronary angiography.
INTERVENTIONS AND MAIN OUTCOME MEASURESCoronary artery plaque burden was assessed using a 30 MHz intravascular ultrasound catheter during an automated pullback. Proximal coronary artery plaque volume was determined using a validated edge-detection algorithm following three-dimensional computerized reconstruction. Central arterial stiffness was assessed in each patient using applanation tonometry to radial, carotid and femoral pulses, with derivation of aortic pressure augmentation and pulse wave velocity using pulse wave analysis.
RESULTSIn 35 patients (61 ± 2 years), proximal coronary arterial plaque volume was 5.9 ± 0.6 mm/mm of vessel. Plaque volume correlated positively with carotid-radial pulse wave velocity (r = 0.47, P = 0.008) and appeared to correlate with carotid–femoral pulse wave velocity (r = 0.34, P = 0.07). Aortic augmentation (r = 0.24, P = 0.16), augmentation index (r = 0.3, P = 0.08), and pulse pressure (r = 0.22, P = 0.2) did not correlate significantly with proximal coronary artery plaque volume.
CONCLUSIONSNon-invasive measures of carotid-radial pulse wave velocity correlate with the extent of coronary artery plaque volume and may be a useful non-invasive surrogate marker for the extent of coronary atherosclerosis. Our findings are consistent with the suggestion that central aortic stiffness may promote the development of coronary atherosclerosis and ischaemic heart disease.
Objectives This study sought to assess the prevalence of normal levels of high sensitivity C-reactive protein (hsCRP) at the very onset of ST-segment elevation myocardial infarction (STEMI). ...Background Levels of hsCRP ≥2 mg/l identify individuals who benefit from lipid lowering and possibly anti-inflammatory agents, but how many patients develop infarction in spite of hsCRP levels <2 mg/l and thus would be ineligible for these treatments? Methods We studied 887 patients with unequivocally documented STEMI as the first manifestation of coronary disease and 887 matched control subjects from urban areas of Italy, Scotland, and China. Blood samples were obtained before reperfusion strategies <6 h from symptoms onset in order to limit acute event-related increases. Results hsCRP values were similar in samples obtained <2 h, 2 to 4 h, and 4 to 6 h from symptoms onset in all ethnic groups, consistent with the delayed hsCRP elevation after myocardial necrosis and thus indicative of pre-infarction levels. Median hsCRP values were significantly higher in patients than in control subjects: 2.49 (interquartile range IQR: 1.18 to 5.55) mg/l versus 1.32 (IQR: 0.58 to 3.10) mg/l (p < 0.0001), which is consistent with previous findings. However, 41% of patients had hsCRP levels <2 mg/l and conversely, 37% of control subjects had values ≥2 mg/l. Conclusions The measurement of hsCRP, with a 2 mg/l cutoff, would not have predicted 41% of unequivocally documented STEMIs in 3 ethnic groups without evidence of previous coronary disease, thus indicating both its limitations as an individual prognostic marker and as an indicator of a generalized inflammatory pathogenetic component of STEMI. New specific prognostic and therapeutic approaches should be found for such a large fraction of patients at risk.
We aimed to establish the feasibility of single-heartbeat 320-multidetector computed tomographic coronary angiography (CTCA) and assess variables affecting image quality.
Consecutive patients (n = ...249, 38% male) underwent CTCA. Two observers assessed image quality using a 4-point scale (1, excellent; 4, poor).
Mean heart rate was 60 beats per minute (95% confidence interval, 59-62); body mass index, 29 kg/m (28-30); and dose-length product, 283 mGy·cm (266-301). During scanning, 133 (51%) received sublingual glyceryl trinitrate (GTN), 9 (4%) had ectopics, and 12 (5%) had atrial fibrillation. Diagnostic image quality was obtained in 99% with mean image quality of 1.4 (1.3, 1.5). Age, sex, atrial fibrillation, ectopics, diabetes mellitus (12%), and obstructive disease were not related to image quality. A lower heart rate and GTN were associated with improved image quality (P ≤ 0.001).
Optimal image quality in single-heartbeat 320-multidetector CTCA is achievable in 99% of unselected patients. Image quality is improved by lower heart rate and GTN.
Abstract Radiation exposure in cardiac imaging is a major healthcare concern and low-dose cardiac imaging has important implications for patients. We describe the application of a low-dose ...comprehensive cardiac computed tomography protocol that assesses anatomy, function, perfusion and viability with correlations to invasive coronary angiography and magnetic resonance imaging.
Upregulation of vascular B
1
kinin receptor expression has been reported in human atheroma, but its role remains unclear. We examined vasomotor and fibrinolytic responses to selective B
1
and B
2
...kinin receptor agonism in the human femoral circulation and correlated responses with femoral arterial plaque load. Femoral arterial cross-sectional area, blood flow and plaque volume were determined using intravascular ultrasound and Doppler during selective arterial infusion of Lys-des-Arg
9
-bradykinin (B
1
agonist), bradykinin (B
2
agonist) and sodium nitroprusside in eleven patients undergoing diagnostic coronary angiography. Net release of tissue plasminogen activator was determined across the femoral vascular bed. Mean femoral arterial plaque load was 8.1 (±0.9) mm
3
/mm of vessel. Bradykinin and sodium nitroprusside caused dose-dependent increases in femoral blood flow (
p
< 0.05 and
p
< 0.005, respectively). Bradykinin caused a dose-dependent increase in net tissue plasminogen activator release (
p
< 0.05), which was augmented by angiotensin-converting enzyme inhibition (
p
< 0.05). There were no correlations between plaque load and bradykinin-mediated vasodilation or tissue plasminogen activator release. Lys-des-Arg
9
-bradykinin had no effect on blood flow or tissue plasminogen activator release. The vasomotor and fibrinolytic actions of bradykinin in the femoral circulation are mediated solely by the B
2
kinin receptor, irrespective of the presence of atheroma. In keeping with previous data, bradykinin-mediated tissue plasminogen activator release was augmented in the presence of angiotensin-converting enzyme inhibition consistent with its putative vascular protective effect.
The association between raised plasma cholesterol and cardiovascular risk is well established, with consistent evidence associating LDL-cholesterol reduction with a reduction in primary and secondary ...cardiovascular events. It is believed that intensive lipid lowering may improve clinical outcomes further by acting to stabilise plaque and preventing plaque progression, ultimately reducing plaque vulnerability. However, it remains uncertain whether a continued clinical benefit occurs with intensive lipid lowering or if there is a threshold level below which no further benefit occurs.
It remains unclear whether myocardial ischemia due to coronary microvascular dysfunction is the cause of chest pain in syndrome X (chest pain, ischemic-like stress ECG despite angiographically normal ...coronary arteries). To assess the function of the coronary microcirculation and its relation to pain perception, we measured myocardial blood flow (MBF) and coronary vasodilator reserve (CVR) in 29 patients with syndrome X and 20 matched normal control subjects.
MBF at rest and after intravenous dipyridamole (0.56 mg.kg-1 over 4 minutes) was measured using positron emission tomography with H2(15)O. CVR was calculated as MBFdipyridamole/MBFrest. ECG changes and chest pain after dipyridamole in syndrome X were compared with those in 35 patients with coronary artery disease (CAD). Resting and postdipyridamole MBFs were homogeneous throughout the left ventricle in syndrome X patients and control subjects. MBF was 1.05 (0.25), mean (SD) versus 1.00 (0.22) mL.min-1.g-1 (P = NS) at rest and 2.73 (0.81) versus 3.00 (1.00) mL.min-1.g-1 (P = NS) after dipyridamole in patients and control subjects, respectively. CVRs were 2.66 (0.76) and 3.06 (1.08) (P = NS) and after correction of resting MBF for rate-pressure product were 2.35 (0.83) and 2.34 (0.90) (P = NS) in patients and control subjects, respectively. Female syndrome X patients had higher resting MBF than males, at 1.18 (0.20) versus 0.88 (0.19) mL.min-1.g-1 (P < .001). Chest pain after dipyridamole occurred in syndrome X as frequently as in CAD (21/29 versus 22/35, P = NS).
When patients with syndrome X are compared with control subjects, no differences are found in MBF either at rest or after dipyridamole, despite syndrome X patients experiencing chest pain after dipyridamole to the same extent as patients with CAD. These findings, together with the absence of any relation among MBF, chest pain, and ECG changes under stress, cast further doubt on ischemia as the basis of the chest pain, at least in the majority of syndrome X patients.
Invasive coronary angiography is the gold standard means of imaging bypass vessels and carries a small but potentially serious risk of local vascular complications, including myocardial infarction, ...stroke and death. We evaluated computed tomography as a non-invasive means of assessing graft patency.
Fifty patients with previous coronary artery bypass surgery who were listed for diagnostic coronary angiography underwent contrast enhanced computed tomography angiography using a 16-slice computed tomography scanner. Images were retrospectively gated to the electrocardiogram and two dimensional axial, multiplanar and three dimensional reconstructions acquired. Sensitivity, specificity, positive and negative predictive value, accuracy and level of agreement for detection of graft patency by multidetector computed tomography.
A total of 116 grafts were suitable for analysis. The specificity of CT for the detection of graft patency was 100%, with a sensitivity of 92.8%, positive predictive value 100%, negative predictive value 85.8% and an accuracy of 94.8%. The kappa value of agreement between the two means of measuring graft patency was 0.9. Mean radiation dose was 9.0 +/- 7.2 mSv for coronary angiography and 18.5 +/- 4 mSv for computed tomography. Pooled analysis of eight studies, incorporating 932 grafts, confirmed a 97% accuracy for the detection of graft patency by multidetector computed tomography.
Computed tomography is an accurate, rapid and non-invasive method of assessing coronary artery bypass graft patency. However, this was achieved at the expense of an increase in radiation dose.
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