Roberto Caldeira Cury

Dipyridamole stress and rest myocardial perfusion by 64-detector row computed tomography in patients with suspected coronary artery disease.

Recently, stress myocardial computed tomographic perfusion (CTP) was shown to detect myocardial ischemia. Our main objective was to evaluate the feasibility of dipyridamole stress CTP and compare it to single-photon emission computed tomography (SPECT) to detect significant coronary stenosis using invasive conventional coronary angiography (CCA; stenosis >70%) as the reference method. Thirty-six patients (62 +/- 8 years old, 20 men) with previous positive results with SPECT (<2 months) as the primary inclusion criterion and suspected coronary artery disease underwent a customized multidetector-row CT protocol with myocardial perfusion evaluation at rest and during stress and coronary CT angiography (CTA). Multidetector-row computed tomography was performed in a 64-slice scanner with dipyridamole stress perfusion acquisition before a second perfusion/CT angiographic acquisition at rest. Independent blinded observers performed analysis of images from CTP, CTA, and CCA. All 36 patients completed the CT protocol with no adverse events (mean radiation dose 14.7 +/- 3.0 mSv) and with interpretable scans. CTP results were positive in 27 of 36 patients (75%). From the 9 (25%) disagreements, 6 patients had normal coronary arteries and 2 had no significant stenosis (8 false-positive results with SPECT, 22%). The remaining patient had an occluded artery with collateral flow confirmed by conventional coronary angiogram. Good agreement was demonstrated between CTP and SPECT on a per-patient analysis (kappa 0.53). In 26 patients using CCA as reference, sensitivity, specificity, and positive and negative predictive values were 88.0%, 79.3%, 66.7%, and 93.3% for CTP and 68.8, 76.1%, 66.7%, and 77.8%, for SPECT, respectively (p = NS). In conclusion, dipyridamole CT myocardial perfusion at rest and during stress is feasible and results are similar to single-photon emission CT scintigraphy. The anatomical-perfusion information provided by this combined CT protocol may allow identification of false-positive results by SPECT.

Dipyridamole stress and rest transmural myocardial perfusion ratio evaluation by 64 detector-row computed tomography

BACKGROUND Myocardial stress CT perfusion (CTP) can detect myocardial ischemia. OBJECTIVE We evaluated the transmural perfusion ratio (TPR) of dipyridamole stress CTP to detect significant coronary stenosis (>70%) defined by quantitative invasive coronary angiography (ICA). METHODS Twenty-six patients (61.6 ± 8.0 years old; 14 males), without prior myocardial infarction, with positive single-photon emission computed tomography (SPECT; <2 months) and clinical indication for ICA, underwent a customized multidetector-row CT (MDCT) protocol with rest/stress myocardial perfusion evaluation and coronary CT angiography. TPR was defined as mean subendocardial divided by mean subepicardial attenuation and quantified on rest and stress MDCT images. Abnormal TPR was defined as 2 SDs below the mean rest TPR. RESULTS All 26 patients completed the CT protocol with no adverse events. Rest TPR was measured in all patients with a mean of 1.06 ± 0.11, and abnormal TPR was considered <0.85. For 6 patients with normal coronary arteries by ICA, the mean TPR of territories with a previous positive perfusion defect in SPECT was 1.02 ± 0.18 (95% CI, 0.86-1.18; n = 6), and mean TPR of territories without perfusion defect in SPECT was 1.03 ± 0.09 (95% CI, -0.95 to 1.11; n = 12; P = 0.83). Mean stress TPR in territories with positive SPECT and significant coronary artery disease by quantitative ICA was 0.71 ± 0.13 (95% CI, -0.64 to 0.77) and in the remote myocardial was 1.01 ± 0.09 (95% CI, -0.96 to 1.06; P < 0001). In these territories, a significant Pearsons correlation was observed (r = -0.74, P < 0.001). CONCLUSION TPR has a good correlation with SPECT and ICA to detect significant coronary stenosis.

Additional value of dipyridamole stress myocardial perfusion by 64-row computed tomography in patients with coronary stents

BACKGROUND Coronary computed tomography angiography (CTA) is a well-established diagnostic tool for coronary artery disease (CAD). However, coronary segments with prior stent implantation visualized with CTA may have limited evaluation and reduced accuracy. OBJECTIVE We assessed the incremental value of stress myocardial CT perfusion (CTP) over anatomical assessment by coronary CTA alone in patients with stents, using quantitative invasive coronary angiography (≥50%) as reference. METHODS Forty-six patients (56.9 ± 7.2 years; 28 men) referred to invasive coronary angiography were evaluated, combining coronary CTA and dipyridamole stress myocardial CTP with 64 detector-row CT. Coronary CTA was evaluated for ≥50% coronary stenosis, and myocardial CTP was used to potentially reclassify coronary territories, including those with stents and poorly evaluated stents because of artifacts. RESULTS We evaluated 138 coronary territories, 62 with ≥1 stent. From these, 21 (34%) territories had adequately evaluated stents, 28 (45%) had limitedly evaluated stents still allowing diagnosis, and 13 (21%) had inadequately evaluated stents (no luminal assessment possible). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for coronary CTA in stent territories were, respectively, 85%, 77%, 87%, 74%, and 81%, and the combined use of coronary CTA and myocardial CTP were 88%, 95%, 97%, 81%, and 91% (P = 0.0292). In territories with impaired stent evaluation (limited or inadequate), the diagnostic performance of coronary CTA alone was 83%, 72%, 79%, 76% and 77%, and combined with myocardial CTP were 87%, 94%, 95%, 85%, and 91% (P = 0.036). CONCLUSION The combined evaluation of coronary CTA and stress myocardial CTP improved the diagnostic accuracy for the detection of significant obstructive CAD in patients with stents.

Images in cardiovascular medicine. Left main coronary artery compression syndrome: evaluation with 64-slice cardiac multidetector computed tomography.

A 28-year-old man presented to the emergency department with progressive shortness of breath complicated by large hemoptysis. At 3 months of age, he had been diagnosed with a “hole in his heart” in the Ukraine and had undergone 3 coronary catheterizations (2 in Russia, 1 in India; results unavailable). His parents had declined options for treatment. After stabilization in the emergency department, he was transferred to coronary care, where echocardiography demonstrated a persistent ductus arteriosus (PDA) measuring 0.9×2.0 cm with a right-to-left shunt consistent with Eisenmenger syndrome. Left ventricular function was severely impaired (ejection fraction=21%). Cardiac 64-slice multidetector computed tomography (MDCT) was undertaken to provide optimal depiction of the PDA and main pulmonary artery (PA) and confirmed a widely patent PDA measuring 2.0 cm in largest diameter (Figure …A 28-year-old man presented to the emergency department with progressive shortness of breath complicated by large hemoptysis. At 3 months of age, he had been diagnosed with a “hole in his heart” in the Ukraine and had undergone 3 coronary catheterizations (2 in Russia, 1 in India; results unavailable). His parents had declined options for treatment. After stabilization in the emergency department, he was transferred to coronary care, where echocardiography demonstrated a persistent ductus arteriosus (PDA) measuring 0.9×2.0 cm with a right-to-left shunt consistent with Eisenmenger syndrome. Left ventricular function was severely impaired (ejection fraction=21%). Cardiac 64-slice multidetector computed tomography (MDCT) was undertaken to provide optimal depiction of the PDA and main pulmonary artery (PA) and confirmed a widely patent PDA measuring 2.0 cm in largest diameter (Figure …

Coronary computed tomography angiography in the assessment of acute chest pain in the emergency room.

The coronary computed tomography angiography has recently emerged as an accurate diagnostic tool in the evaluation of coronary artery disease, providing diagnostic and prognostic data that correlate directly with the data provided by invasive coronary angiography. The association of recent technological developments has allowed improved temporal resolution and better spatial coverage of the cardiac volume with significant reduction in radiation dose, and with the crucial need for more effective protocols of risk stratification of patients with chest pain in the emergency room, recent evaluation of the computed tomography coronary angiography has been performed in the setting of acute chest pain, as about two thirds of invasive coronary angiographies show no significantly obstructive coronary artery disease. In daily practice, without the use of more efficient technologies, such as coronary angiography by computed tomography, safe and efficient stratification of patients with acute chest pain remains a challenge to the medical team in the emergency room. Recently, several studies, including three randomized trials, showed favorable results with the use of this technology in the emergency department for patients with low to intermediate likelihood of coronary artery disease. In this review, we show data resulting from coronary angiography by computed tomography in risk stratification of patients with chest pain in the emergency room, its diagnostic value, prognosis and cost-effectiveness and a critical analysis of recently published multicenter studies.

Current Role of Cardiac Magnetic Resonance Imaging in Hypertrophic Cardiomyopathy

Fábio Vieira Fernandes,1,2 Juliana Hiromi Silva Matsumoto Bello,3,4,5 Afonso Akio Shiozaki,6,7 Roberto Caldeira Cury4 Instituto Dante Pazzanese de Cardiologia,1 São Paulo, SP; UMC Imagem,2 Uberlândia, MG; Hospital do Coração,3 São Paulo, SP; DASA,4 São Paulo, SP; Hospital Samaritano,5 São Paulo, SP; UNITOM, Centro Diagnóstico, Hospital Paraná,6 Maringá, PR; Ômega Diagnósticos,7 Londrina, PR – Brasil

Image Quality and Radiation Exposure Comparison of a Double High-Pitch Acquisition for Coronary Computed Tomography Angiography Versus Standard Retrospective Spiral Acquisition in Patients With Atrial Fibrillation

Objective The aim of this study was to compare image quality and radiation dose of coronary computed tomography (CT) angiography performed with dual-source CT scanner using 2 different protocols in patients with atrial fibrillation. Methods Forty-seven patients with AF underwent 2 different acquisition protocols: double high-pitch (DHP) spiral acquisition and retrospective spiral acquisition. The image quality was ranked according to a qualitative score by 2 experts: 1, no evident motion; 2, minimal motion not influencing coronary artery luminal evaluation; and 3, motion with impaired luminal evaluation. A third expert solved any disagreement. Results A total of 732 segments were evaluated. The DHP group (24 patients, 374 segments) showed more segments classified as score 1 than the retrospective spiral acquisition group (71.3% vs 37.4%). Image quality evaluation agreement was high between observers (&kgr; = 0.8). There was significantly lower radiation exposure for the DHP group (3.65 [1.29] vs 23.57 [10.32] mSv). Conclusions In this original direct comparison, a DHP spiral protocol for coronary CT angiography acquisition in patients with atrial fibrillation resulted in lower radiation exposure and superior image quality compared with conventional spiral retrospective acquisition.