Miguel A. Rosales

Early Assessment of Myocardial Viability by the Use of Delayed Enhancement Computed Tomography After Primary Percutaneous Coronary Intervention

OBJECTIVES We sought to explore the relationship between established parameters of reperfusion and the extent of myocardial damage measured by the delayed enhancement (DE) of iodinated contrast by multidetector computed tomography (MDCT) immediately after primary percutaneous coronary intervention (PCI). BACKGROUND Early detection of myocardial viability should be valuable for risk stratification of patients with reperfused acute myocardial infarction (AMI). METHODS Consecutive patients without a history of previous AMI who underwent primary PCI for an ST-segment elevation AMI were examined by DE-MDCT without an additional contrast injection immediately after completion of PCI. No medication was administrated to lower the heart rate. Dose modulation lead to an approximate mean radiation dose of 5.5 mSv. RESULTS Thirty patients constituted the study population. Mean age was 61.4 +/- 15.6 years, 24 (80%) were men, and 4 (13%) were diabetic. Although post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 was achieved in all patients, DE was detected in 14 (47%) patients. Age, sex, hypertension, diabetes, smoking history, serum creatinine levels, and pain duration were not associated with the presence of DE. Door-to-balloon time (DE 70.3 +/- 33.6 min vs. non-DE 98.3 +/- 70.7 min, p = 0.19) and lesion crossing time (DE 18.6 +/- 11.4 min vs. non-DE 16.4 +/- 9.6 min, p = 0.58) did not differ between groups. The TIMI myocardial perfusion grade (0 to 1 vs. 2 to 3) after stent implantation and electrocardiogram ST-segment resolution (<50% or >/=50%) were associated with the presence of DE (p = 0.001 and p = 0.02, respectively). Pre-discharge left ventricular ejection fraction was lower in DE than in non-DE patients (44.6 +/- 12.4% vs. 54.1 +/- 10.3%, respectively, p = 0.05). Hospitalization days (DE 5.6 +/- 3.8 vs. non-DE 4.8 +/- 1.0, p = 0.41) and 6-month cardiac events (DE 3 of 14 vs. non-DE 1 of 16, p = 0.22) did not differ between groups. CONCLUSIONS Early detection of myocardial viability immediately after primary PCI by the use of DE-MDCT is related to clinical and angiographic parameters of myocardial reperfusion.

Prevalence and characteristics of major and minor coronary artery anomalies in an adult population assessed by computed tomography coronary angiography

AIMS There is conflicting data regarding the prevalence and characteristics of coronary artery anomalies (CAAs). We sought to explore the prevalence and characteristics of major and minor CAAs using computed tomography coronary angiography (CCTA). METHODS AND RESULTS We prospectively studied 577 patients in sinus rhythm referred for control of stents or for screening due to the presence of multiple risk factors (53%), or due to chest pain, equivalent symptoms or inconclusive stress tests (47%). 40 and 64 slice CT scanners were used. The mean age was 61 +/- 11 years and 81% were male. We identified CAAs in 121 (21.0%) patients. Anomalous origination of a coronary artery from the opposite sinus (ACAOS) were identified in 6/577 (1%) patients. Coronary ectasia or aneurysm was present in 10/577 (1.7%) patients. One-hundred and nine intramuscular segments (MB) were found in 100/577 (17.3%) patients. Coronary hypoplasia was identified in 3/577 (0.5%) patients, all involving the RCA, and 3/577 (0.5%) patients had an absent left main coronary artery. None of the segments with ACAOS (proximal segment) or MB had atherosclerotic plaque. CONCLUSIONS CAAs were highly prevalent along the coronary tree and anatomical characteristics that might help stratify the risk and guide therapy of CAAs could be easily identified with CCTA.

Chronic myocardial infarction detection and characterization during coronary artery calcium scoring acquisitions

BACKGROUND Hypoenhanced regions on multidetector CT (MDCT) coronary angiography correlate with myocardial hyperperfusion. In addition to a limited capillary density, chronic myocardial infarction (MI) commonly contains a considerable amount of adipose tissue. OBJECTIVE We explored whether regional myocardial hypoenhancement on contrast-enhanced MDCT could be identified with standard coronary artery calcium (CAC) scoring acquisitions with noncontrast CT. METHODS Consecutive patients with a history of MI who were referred for contrast-enhanced MDCT from November 2006 until March 2009 were studied. Noncontrast CT for CAC scoring was also performed. The correlation between regional myocardial hypoenhancement on contrast-enhanced CT and regional myocardial hypoattenuated areas on noncontrast CT was defined. RESULTS Eighty-three patients (mean age, 61.5+/-12.5 years; n=67; 81% male) with previous MI were studied. A total of 1411 myocardial segments were evaluated. Two hundred thirty-nine segments (17%) showed myocardial hypoenhancement by MDCT and 140 segments (9.6%) by CAC. On a patient level, noncontrast CT showed a sensitivity, specificity, positive predictive value, (PPV) and negative predictive value (NPV) of 66% (95% CI, 0.53-0.77), 100% (95% CI, 0.76-1.00), 100% (95% CI, 0.90-1.00), and 41% (95% CI, 0.26-0.58), respectively, to detect myocardial hypoenhancement. On a per segment level, noncontrast CT showed a sensitivity, specificity, PPV, and NPV of 58% (95% CI, 0.51-0.64), 100% (95% CI, 0.99-1.00), 99% (95% CI, 0.94-1.00), and 92% (95% CI, 0.90-0.93), respectively, to detect myocardial hypoenhancement. CONCLUSIONS Our findings suggest that chronic MI can be detected with standard CAC scoring acquisitions.

Guidance of percutaneous coronary interventions by multidetector row computed tomography coronary angiography.

Guidance of percutaneous coronary interventions (PCI) by intravascular ultrasound (IVUS) provides more precise information in terms of quantitative measurement and qualitative assessment of coronary artery disease (CAD) than does conventional angiography. Several studies have tested the efficacy of IVUS to guide stent implantation. However, the conflicting results have left behind a continued debate as to whether IVUS-guided PCI has an impact on clinical outcome and angiographic restenosis. IVUS and computed tomography coronary angiography (CTCA) share the ability to evaluate the lumen along with the vessel wall, enabling characterisation of proximal and distal reference segments. Nevertheless, IVUS imaging is expensive and usually precluded in severe stenoses. In the present article, we discuss the potential application of CTCA for the guidance of PCI, particularly of complex lesions such as chronic total occlusions (CTO) and bifurcations.

Modified scan protocol using multislice CT coronary angiography allows high quality acquisitions in obese patients: a case report

Nearly every cardiovascular functional imaging technique has difficulties in dealing with obese patients and MSCT-CA is not an exception. Excluding such large portion of the coronary population remains a grim limitation of the technique and requires thus a comprehensive re-evaluation. In this report, we show that excellent image quality could be achieved in a morbidly obese patient with the aid of proper management of scan protocols and bolus administration. Providing this complex population an accurate, non-invasive imaging technique represents a major step-forward in cardiovascular imaging.