Shmuel Rispler

16-MDCT coronary angiography versus invasive coronary angiography in acute chest pain syndrome: a blinded prospective study.

OBJECTIVE The purpose of our study was to prospectively evaluate the usefulness of CT coronary angiography versus invasive coronary angiography for the detection of clinically significant coronary artery disease in patients hospitalized for acute chest pain syndrome. SUBJECTS AND METHODS Sixty-six consecutive patients (52 men and 14 women; average age, 57 +/- 11 [SD] years) who were hospitalized for acute chest pain syndrome underwent CT coronary angiography and invasive coronary angiography within an average time interval of 4 days. ECG-gated CT coronary angiography was performed with a 16-MDCT scanner (0.42-sec rotation time, 16 x 0.75 mm detector collimation). Beta-blockers were not administered routinely, and thus the average heart rate was 71 +/- 11 beats per minute. CT coronary angiographic images were evaluated concurrently by two radiologists, who were blinded to invasive coronary angiography results, for stenoses having a diameter of 50% or more, using a 15-segment classification, including all segments 2 mm or more in diameter. The consensus interpretation was compared with results of invasive coronary angiography. RESULTS CT coronary angiography was technically successful in 59 patients (89%). After exclusion of 20 (3.1%) of 649 coronary segments, which were classified as nonevaluable by CT coronary angiography, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT coronary angiography for identifying significant coronary artery disease in the remaining 629 coronary segments were 80% (68/85), 89% (482/544), 52% (68/130), 97% (482/499), and 87% (550/629), respectively. The overall accuracy for the main vessels (left main, left anterior descending, left circumflex, and right coronary arteries) was 93%, 88%, 86%, and 86%, respectively. CONCLUSION CT coronary angiography using a 16-MDCT scanner enables accurate noninvasive detection of significant coronary artery disease in patients hospitalized for acute chest pain syndrome. Furthermore, relative high sensitivity and specificity of CT coronary angiography can be achieved without pharmacologic manipulation of patient heart rates.

Automatic determination of minimal cardiac motion phases for computed tomography imaging: initial experience

Low motion phases for cardiac computed tomography reconstructions are currently detected manually in a user-dependent selection process which is often time consuming and suboptimal. The concept of motion maps was recently introduced to achieve automatic phase selection. This pilot study compared the accuracy of motion-map phase selection to that with manual iterative selection. The study included 20 patients, consisting of one group with low and one with high heart rate. The technique automatically derives a motion strength function between multiple low-resolution reconstructions through the cardiac cycle, with periods of lowest difference between neighboring phases indicating minimal cardiac motion. A high level of agreement was found for phase selection achieved with the motion map approach compared with the manual iterative selection process. The motion maps allowed automated quiescent phase detection of the cardiac cycle in 85% of cases, with best results at low heart rates and for the left coronary artery. They can also provide additional information such as the presence of breathing artifacts. Motion maps show promise as a rapid off-line tool to automatically detect quiescent cardiac phases in a variety of patients.

Patient safety and outcomes from live case demonstrations of interventional cardiology procedures

OBJECTIVES The goal of this study was to examine the safety and results of interventional procedures performed during the broadcast of live case demonstrations. BACKGROUND Professional meetings using live case demonstrations to present cutting-edge technology are considered a valuable educational resource. There is an ongoing discussion on whether patients who are treated during live case demonstrations are exposed to a higher risk. METHODS Between 1998 and 2010, 101 patients were treated during live transmissions from a single center in 15 invasive-cardiology conferences. Technical success was defined as the ability to effectively perform the planned procedure without any major complication. The primary endpoint of the study was the composite occurrence of death, myocardial infarction, or stroke. RESULTS The interventional procedures included coronary (n=66), carotid (n=15), peripheral (n=1), valvular (n=2), congenital heart disease (n=12), and complex electrophysiological mapping and ablation interventions (n=7). In 4 cases, the intended procedure was not done. The procedure was technically successful in 95%. In 5 cases, the procedure was unsuccessful because of the inability to cross a chronic total occlusion. There were no deaths during the hospital stay, and the composite primary endpoint occurred in 2 patients: a minor stroke following an atrial fibrillation ablation and a rise in serum troponin levels after percutaneous coronary intervention. These results were no different from those of 66 matched controls who underwent procedures performed by the same operators but not as live case demonstrations (relative risk: 0.32; 95% confidence interval: 0.02 to 3.62, p=0.62). CONCLUSIONS In this consecutive series of interventional cardiology procedures that were performed by expert operators during live demonstration courses, the procedural and 30-day clinical outcomes were similar to those found in daily practice and to those that have been reported in the contemporary published data. These results suggest that broadcasting live case demonstrations in selected patients from selected centers may be safe.

Missed diagnosis of severe symptomatic aortic stenosis.

Patients with angina pectoris and congestive heart failure with a systolic murmur should be suspected of having significant AS. These patients are frequently women with atrial fibrillation and no left ventricular hypertrophy criteria on the electrocardiogram. Echocardiography with calculation of the aortic valve area is indicated in all these patients.

Diagnostic accuracy of myocardial hypoenhancement on multidetector computed tomography in identifying myocardial infarction in patients admitted with acute chest pain syndrome.

Objective: To evaluate prevalence and diagnostic accuracy of myocardial hypoenhancement (MH) using multidetector computed tomography (MDCT) in patients admitted for acute chest pain syndromes. Methods: Sixty-nine patients underwent first-pass MDCT, coronary angiography, and echocardiography. Using a standardized analysis protocol, left ventricular short-axis reformations were evaluated for presence, size, and density of MH in 16 myocardial segments. These were correlated with the presence and location of myocardial infarction (MI), regional myocardial dysfunction, and coronary artery disease. Results: Myocardial hypoenhancement was found in acute MI (27/35), healed MI (6/14), unstable angina (3/9), and atypical chest pain (0/11). Sensitivity, specificity, and positive and negative predictive values of MH for diagnosing any MI were 67%, 85%, 92% and 52%, respectively. Conclusions: The presence of MH on MDCT in acute chest pain patients has high positive predictive value and specificity but only moderate sensitivity for presence of acute or healed MI using the strict criteria proposed in this study.

Anomalous origin of right coronary artery: Diagnosis and dynamic evaluation with multidetector computed tomography

16 slice multidetector CT findings of an anomalous right coronary artery originating from the left sinus of Valsalva are presented. Multidetector CT depicted the malignant coronary anomaly in great anatomic detail as well as enabled dynamic evaluation through the cardiac cycle, documenting a substantial reduction in arterial diameter during peak systole. This case illustrates the full capabilities of multidetector cardiac CT in the evaluation of coronary artery pathology.

Thermographic imaging in the beating heart: a method for coronary flow estimation based on a heat transfer model.

Intraoperative thermographic imaging in open-chest conditions can provide the surgeon with important qualitative information regarding coronary flow by utilizing heat transfer analysis following injection of cold saline into the aortic root. The heat transfer model is based on the assumption that the epicardial temperature changes are mainly due to convection of heat by the blood flow, which may, therefore, be estimated by measuring the temperature variations. Hearts of eight dogs were exposed and imaged by a thermographic camera. Flow in the left arterial descending (LAD) coronary branch was measured by a transit-time flowmeter. 20 ml of cold saline were injected into the aortic root (just after the aortic valve) and the epicardial temperature images were recorded at end-diastole, for 20-30 s. Different flow rates were achieved by 1 min occlusion of the LAD, which affected a reactive hyperemic response. The dynamics of the temperature in the arterial coronary tree was obtained by averaging the temperature over an edge-detected arterial segment for each frame. The heat transfer equation was curve-fitted, and the flow-dependent heat transfer index was correlated with the experimentally determined coronary flow (r = 0.69, p < 0.001). In summary: a method for quantitative estimation of coronary blood flow by thermography and heat transfer analysis was developed and tested in animal experiments. This method can provide important information regarding coronary blood flow during open-chest surgical procedures.

Contrast enhanced multi‐detector computed tomography coronary angiography versus conventional invasive quantitative coronary angiography in acute coronary syndrome patients–correlation and bias

Background: Previous studies that compared multi‐detector computed tomography (MDCT) non‐invasive coronary angiography with conventional coronary angiography, did not assessed the ability of MDCT to detect stenotic lesions correctly in acute coronary syndromes (ACS) patients. The aim of the present study was to assess prospectively the correlation and bias between 16‐slice MDCT coronary angiography and quantitative coronary angiography analysis (QCA) in these patients. Methods: Patients underwent electrocardiogram‐gated, 16‐slice MDCT coronary angiography and routine invasive percutaneous coronary angiography with quantitative coronary angiography (QCA) analysis blinded to MDCT results. The correlation and the bias between the results of MDCT and QCA were assessed in segments observed by both modalities in vessels⩾2 mm in diameter. Results: 59 patients (81% male, age 56±11 years), admitted due to ACS, underwent MDCT and invasive coronary angiography. 544 segments were analyzed. The correlations between MDCT and QCA observed for the left anterior descending coronary artery (LAD), the left circumflex coronary artery (Cx), the right coronary artery (RCA) and for all analyzed segments were 0.74 (P<0.0001), 0.54 (P<0.009), 0.72 (P<0.0001) and 0.70 (P<0.0001), respectively. By Bland‐Altman analysis, a small overestimation of the lesion severity with MDCT of 4.8% for the LAD, 5.9% for the Cx, and 3.3% for the RCA was observed. Conclusions: In ACS patients, MDCT contrast‐enhanced coronary angiography provides good quantification of the luminal diameter as compared to coronary angiography, and it is characterized by a small overestimation bias.

Integrated SPECT/CT for assessment of haemodynamically significant coronary artery lesions in patients with acute coronary syndrome

PurposeEarly risk stratification in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) is important since the benefit from more aggressive and costly treatment strategies is proportional to the risk of adverse clinical events. In the present study we assessed whether hybrid single photon emission computed tomography (SPECT)/coronary computed tomography angiography (CCTA) technology could be an appropriate tool in stratifying patients with NSTE-ACS.MethodsSPECT/CCTA was performed in 90 consecutive patients with NSTE-ACS. The Thrombolysis in Myocardial Infarction risk score (TIMI-RS) was used to classify patients as low- or high-risk. Imaging was performed using SPECT/CCTA to identify haemodynamically significant lesions defined as >50% stenosis on CCTA with a reversible perfusion defect on SPECT in the corresponding territory.ResultsCCTA demonstrated at least one lesion with >50% stenosis in 35 of 40 high-risk patients (87%) as compared to 14 of 50 low-risk patients (35%; TIMI-RS <3; p <0.0001). Of the 40 high-risk and 50 (16%) low-risk TIMI-RS patients, 16 (40%) and 8 (16%), respectively, had haemodynamically significant lesions (p = 0.01). Patients defined as high-risk by a high TIMI-RS, a positive CCTA scan or both (n = 45) resulted in a sensitivity of 95%, specificity of 49%, PPV of 35% and NPV of 97% for having haemodynamically significant coronary lesions. Those with normal perfusion were spared revascularization procedures, regardless of their TIMI-RS.ConclusionNoninvasive assessment of coronary artery disease by SPECT/CCTA may play an important role in risk stratification of patients with NSTE-ACS by better identifying the subgroup requiring intervention.

Multidetector computed tomography predictors of late ventricular remodeling and function after acute myocardial infarction

BACKGROUND Despite advent of rapid arterial revascularization as 1st line treatment for acute myocardial infarction (AMI), incomplete restoral of flow at the microvascular level remains a problem and is associated with adverse prognosis, including pathological ventricular remodeling. We aimed to study the association between multidetector row computed tomography (MDCT) perfusion defects and ventricular remodeling post-AMI. METHODS In a prospective study, 20 patients with ST-elevation AMI, treated by primary angioplasty, underwent arterial and late phase MDCT as well as radionuclide scans to study presence, size and severity of myocardial perfusion defects. Contrast echocardiography was performed at baseline and at 4 months follow-up to evaluate changes in myocardial function and remodeling. RESULTS Early defects (ED), late defects (LD) and late enhancement (LE) were detected in 15, 7 and 16 patients, respectively and radionuclide defects in 15 patients. The ED area (r=0.74), and LD area (r=0.72), and to a lesser extent LE area (r=0.62) correlated moderately well with SPECT summed rest score. By univariate analysis, follow-up end-systolic volume index and ejection fraction were both significantly related to ED and LD size and severity, but not to LE size or severity. By multivariate analysis, end-systolic volume index was best predicted by LD area (p<0.05) and ejection fraction by LD enhancement ratio. CONCLUSIONS LD size and severity on MDCT are most closely associated with pathological ventricular remodeling after AMI and may thus play a role in early identification and treatment of this condition.