Valéria de Melo Moreira

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.

The shift from high to low turnover bone disease after parathyroidectomy is associated with the progression of vascular calcification in hemodialysis patients: A 12-month follow-up study

Parathyroidectomy (PTX) may cause low levels of PTH, leading to an excessive reduction of bone turnover, which is associated with poor outcomes in dialysis patients, including vascular calcification (VC). We aimed to prospectively investigate the impact of PTX on bone remodeling and its potential consequence on the progression of VC in hemodialysis patients. In this prospective study, 19 hemodialysis patients with severe secondary hyperparathyroidism (sHPT) were evaluated. All patients underwent laboratorial tests and coronary tomography at baseline and, 6 and 12 months after PTX; bone biopsy was performed at baseline and 12-month. At baseline, all patients had increased PTH levels up to 2500 pg/mL and high turnover bone disease in their bone biopsies. Fourteen (74%) patients had VC. During the follow-up, there was a significant decrease of PTH at 6 and 12-month. At 12-month, 90% of the patients evolved to low turnover bone disease. During the period of the hungry bone syndrome (first 6 months), no change of coronary calcium score was observed. However, calcium score increased significantly thereafter (12th month). There was an association between VC progression and the severity of low turnover bone disease. In conclusion, the shift from high to low turnover bone disease after PTX occurs in parallel to VC progression, contributing to the understanding of the complex pathophysiology involving mineral metabolism and cardiovascular disease in hemodialysis patients.

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.

Parameters of Right Ventricle as etiological distinction between ischemic and non-ischemic dilated cardiomyopathy

Background Dilated left ventricular volumes (VE) is one of the main factors of poor cardiovascular prognosis with systolic dysfunction. Myocardial fibrosis detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) has been recognized in recent years as an independent prognostic factor in dilated cardiomyopathy, in addition to guiding the etiological diagnosis, and most often the only noninvasive way to differentiate ischemic and nonischemic. The aim of our study was to determine the prevalence of myocardial fibrosis in patients with dilated LV and the morphological and functional differences between ischemic and non-ischemic patterns.

Left ventricle morphological and functional characteristics associated to the presence and magnitude of myocardial fibrosis by CMR in hypertrophy cardiomiopathy

Background Hypertrophic cardiomyopathy (HCM) is a common inherited cardiovascular disease present in one in 500 of the general population, and it is main cause of sudden death in young people. The presence of myocardial fibrosis in HCM is very common (more than 2/3 of patients), and its identification by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) helps the diagnosis and it is associated with ventricular arrhythmias and worse prognosis. The aim of our study was to find CMR characteristics that are related to the presence and burden of myocardial fibrosis by CMR in HCM. Methods We evaluated 115 consecutive HCM patients who underwent cardiac MRI and analyzed both the presence/ absence of myocardial fibrosis (LGE) and also its magnitude (estimated as absolute mass of myocardial fibrosis in grams and normalized to LV mass as percentage of LV myocardial mass) with other morphological and functional factors as well as population characteristics. Patients with a history of acute myocardial infarction as well as other cardiomyopathies that could present late enhancement were excluded. Results The mean age was 46.6 ± 16.1 yo, 77% male. Eighty patients (70%) had myocardial fibrosis in cardiac MRI. Patients with myocardial fibrosis had lower ejection fraction of the left ventricle (68.8 vs. 74.6 ± 0.1%, p = 0.011), higher end-systolic volume (45 ± 24 [23 ± 11] vs. 33 ± 12 [18 ± 5] ml [ml/m2], p = 0.027 [p = 0.041]), greater maximum thickness of the ventricular wall (21.9 ± 5.2 vs. 16.4 ± 2.8 mm, p < 0.001) and increased left ventricular mass (192.8 ± 58.1 [98.5 ± 27.0] vs. 157.5 ± 50.4 [82.8 ± 21.5] g[g/m2], p < 0.001 [p = 0.001]). In a logistic regression analysis, only ejection fraction (p = 0.034) and maximum wall thickness (p < 0.001) were independently associated with the presence of fibrosis. Among those with myocardial fibrosis, a greater mass of fibrosis correlated with a lower ejection fraction (r = -0.42, p = 0.003), lower end-systolic volumes (r = 0.56, p < 0.001), greater maximum thickness wall (r = 0.28, p = 0.024) and increased left ventricular mass (r = 0.35, p = 0.017). On the multivariate analysis, only the stroke volume (p < 0.001) and maximum thickness (p = 0.020) were correlated with the mass of myocardial fibrosis. However, when we analyzed the burden of fibrosis in relation to left ventricular mass (percentage of fibrosis) only greater end-systolic volume was independently associated with a higher percentage of fibrosis (r = 0.48, p < 0.001). Conclusions The presence of myocardial fibrosis in patients with HCM is independently related to lower ejection fraction and higher maximum thickness of the ventricular wall. The burden of fibrosis correlated independently with a higher maximum wall thickness (mass of fibrosis) and lower end-systolic volume (mass and percentage of fibrosis).

A new typical finding in late gadolinium enhanced images for the diagnosis of endomyocardial fibrosis - the double V sign

Introduction Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy presenting with ventricular apical filling, possibly containing fibrotic tissue with thrombus and/or calcification. Late gadolinium enhancement (LGE) can detect apical fibrosis in EMF patients, as a hyper intense linear image usually in a letter “V” like shape pointing to the ventricular apex. Recently, we have observed a pattern of a double layer hyper and hypo intense in LGE images, also in a “V” like shape, possibly corresponding to fibrosis plus thrombus/calcification.

Fístula coronária direita (CD) ao tronco pulmonar (TP), com anomalias associadas

Adolescent, 13 yrs, with slight fatigue and cyanosis since birth. No heart failure, oxygen saturation > 80% and continuous murmur +/++ at the inferior left sternal border. Chest x-ray showed higher caliber vessels to the left. Left pulmonary artery hypertension (90/45-60 mm Hg and 7.8 UW) and normotension to the right (20 mm Hg, 1.8 UW). Left pulmonary artery originated from the ascending aorta and the right pulmonary artery filled through a fistula of the right coronary artery to the pulmonary trunk. Different levels of pulmonary artery pressure caused procedure difficulty through the unification of the two systems. The stable clinical picture led to the expectant conduct.

Fístula coronaria derecha (CD) al tronco pulmonar (TP), con anomalías asociadas

Adolescent, 13 yrs, with slight fatigue and cyanosis since birth. No heart failure, oxygen saturation > 80% and continuous murmur +/++ at the inferior left sternal border. Chest x-ray showed higher caliber vessels to the left. Left pulmonary artery hypertension (90/45-60 mm Hg and 7.8 UW) and normotension to the right (20 mm Hg, 1.8 UW). Left pulmonary artery originated from the ascending aorta and the right pulmonary artery filled through a fistula of the right coronary artery to the pulmonary trunk. Different levels of pulmonary artery pressure caused procedure difficulty through the unification of the two systems. The stable clinical picture led to the expectant conduct.

Right coronary (RC) artery fistula to the pulmonary trunk (PT) with associated anomalies

Adolescent, 13 yrs, with slight fatigue and cyanosis since birth. No heart failure, oxygen saturation > 80% and continuous murmur +/++ at the inferior left sternal border. Chest x-ray showed higher caliber vessels to the left. Left pulmonary artery hypertension (90/45-60 mm Hg and 7.8 UW) and normotension to the right (20 mm Hg, 1.8 UW). Left pulmonary artery originated from the ascending aorta and the right pulmonary artery filled through a fistula of the right coronary artery to the pulmonary trunk. Different levels of pulmonary artery pressure caused procedure difficulty through the unification of the two systems. The stable clinical picture led to the expectant conduct.

Common ventricle due to a 52-mm Ventricular Septal Defect (VSD)

Eleven-year-old boy undergoing pulmonary banding at the age of one month due to heart failure. He had normal physical growth, good exercise tolerance and normal arterial saturation. On physical examination, grade 3/6 systolic murmur at the LSB. On ECG, biventricular volume overload, and on chest X-ray, close to normal cardiac silhouette with slightly increased pulmonary vascularity. Atrioventricular and ventriculoarterial concordance with ventricles of similar size and large 52-mm discontinuity of the interventricular septum up to the apex (common ventricle). Surgical ventricular separation implies a high risk of residual defect, in addition to contractile dysfunction. Maintenance of the expectant medical management was chosen.