Experimental studies in the bronchial circulation. Which is the ideal animal model?

Background

The importance of the role of bronchial arteries is notable in modern days thoracic surgery. The significance of their anastomoses with adjusted structures has not yet been sufficiently rated, especially in cases of haemoptysis, heart-lung transplantations and treatment of aneurysms of the thoracic aorta. The need of a thorough study is more relevant than ever and appropriate laboratory animals are required.

Methods

We review the literature in order to highlight the ideal experimental animal for the implementation of pilot programs relative to the bronchial circulation. A comparative analysis of the anatomy of the bronchial arterial system in humans along with these of pigs, dogs, rats, and birds, as being the most commonly used laboratory animals, is presented in details.

Results

The pig has the advantage that the broncho-oesophageal artery usually originates from the aorta as a single vessel, which makes the recognition and dissection of the artery easy to perform. In dogs, there is significant anatomical variation of the origin of the bronchial arteries. In rats, bronchial artery coming from the aorta is a rare event while in birds the pattern of the bronchial artery tree is clearly different from the human analog.

Conclusions

The pig is anatomically and physiologically suited for experimental studies on the bronchial circulation. The suitable bronchial anatomy and physiology along with the undeniable usefulness of the pig in experimental research and the low maintenance cost make the pig the ideal model for experiments in bronchial circulation.     

High red blood cell distribution width is closely associated with risk of carotid artery atherosclerosis in patients with hypertension

BACKGROUND:

A high red blood cell distribution width (RDW) may be associated with adverse outcomes in patients with heart failure and risk of death, and cardiovascular events in people with previous myocardial infarction. Ultrasound detection of carotid plaque helps to identify asymptomatic patients with advanced subclinical atherosclerosis, which can predict risk of cardiovascular death or myocardial infarction. However, the relationship of RDW and carotid artery atherosclerosis in hypertensive people is less certain.

OBJECTIVE:

To evaluate the association between RDW and carotid artery atherosclerosis in people with hypertension.

METHODS:

RDW was determined using a Coulter counter together with white blood cell count in 156 hypertensive inpatients 60 to 85 years of age. Carotid intimal-medial thickness (IMT) and carotid atherosclerotic plaques were identified by ultrasound imaging. Total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglyceride levels were determined using a multichannel analyzer. Systolic and diastolic blood pressures were measured manually.

RESULTS:

The number of patients with carotid artery atherosclerotic plaque, as well as the carotid IMT to inner diameter ratio, were significantly different among the different RDW groups of hypertensive inpatients (P<0.01). With linear regression analysis, increased carotid IMT and higher white blood cell count were identified to be significant and independent contributors to the RDW of hypertensive inpatients (P<0.05).

CONCLUSIONS:

A close relationship between high RDW and IMT, and the incidence of carotid plaque, was identified in 156 hypertensive inpatients.     

A novel method to quantify carotid artery stenosis by Doppler ultrasound: Using the continuity principle

BACKGROUND AND PURPOSE:

A novel method to quantify carotid artery stenosis by using the continuity principle was evaluated. It was hypothesized that the novel method improved the accuracy of carotid ultrasound in assessing carotid artery stenosis.

METHODS:

Forty-nine patients were retrospectively studied. They were at a high risk for stroke and myocardial infarction, with significant cardiovascular risk factors. They were studied by carotid ultrasound as well as by one of the accepted gold standard techniques (computed tomography, magnetic resonance imaging or angiography). The cross-sectional areas of the narrowed part of the carotid arteries were measured using the continuity principle, and the percentage stenosis was thus calculated.

RESULTS:

The analyses showed that the combination of the conventional and novel criteria (ie, classifying a case as significant only if its stenosis was 67% or greater and its peak systolic velocity was 130 cm/s or greater) conferred the highest accuracy in predicting significant carotid stenosis compared with the gold standard techniques.

CONCLUSION:

From a practical point of view, the combined criteria might be useful for improving the accuracy of carotid ultrasound in predicting significant carotid stenosis.     

Extracranial internal carotid arterial disease in children with sickle cell anemia

Background

Sickle cell anemia is one of the commonest causes of stroke in children. It is usually, but not always, associated with intracranial vasculopathy. We have assessed the value of ultrasound screening for extracranial internal carotid artery disease.

Design and Methods

Using Doppler ultrasound scanning, we assessed peak systolic blood velocity, tortuosity and stenosis in the extracranial internal carotid arteries of 236 children with sickle cell anemia. Seventeen of the children had previously had a stroke. All measurements were performed as part of routine clinical care.

Results

The median extracranial internal carotid artery velocity was 148cm/s (5^th centile 84, 95^th centile 236). Higher velocities were significantly correlated with younger age, higher white blood cell counts and higher rates of hemolysis. Fourteen (5.9%) had tortuous extracranial internal carotid arteries and 13 (5.4%) had stenosis or occlusion. None of the children with tortuous vessels but 8 of those with stenosis had previously had a stroke; the presence of stenosis was strongly associated with overt clinical stroke (OR 35.9, 95% C.I. 9.77–132, P<0.001). In 6 children, extracranial stenosis was part of extensive intracranial vasculopathy, but in 2 there was no evidence of intracranial disease. Stenosis seemed to be more common in older children.

Conclusions

Extracranial internal carotid artery stenosis is strongly associated with stroke in children with sickle cell anemia, and may explain some cases of stroke without overt intracranial vasculopathy. Doppler ultrasound scanning of extracranial internal carotid arteries is non-invasive and fairly quick to perform and may identify children at increased risk of stroke who would otherwise be missed. The value of extracranial internal carotid artery scanning should be studied prospectively.     

Debranching Solutions in Endografting for Complex Thoracic Aortic Dissections

Background

Conventional surgical repair of thoracic aortic dissections is a challenge due to mortality and morbidity risks.

Objectives

We analyzed our experience in hybrid aortic arch repair for complex dissections of the aortic arch.

Methods

Between 2009 and 2013, 18 patients (the mean age of 67 ± 8 years-old) underwent hybrid aortic arch repair. The procedural strategy was determined on the individual patient.

Results

Thirteen patients had type I repair using trifurcation and another patient with bifurcation graft. Two patients had type II repair with replacement of the ascending aorta. Two patients received extra-anatomic bypass grafting to left carotid artery allowing covering of zone 1. Stent graft deployment rate was 100%. No patients experienced stroke. One patient with total debranching of the aortic arch following an acute dissection of the proximal arch expired 3 months after TEVAR due to heart failure. There were no early to midterm endoleaks. The median follow-up was 20 ± 8 months with patency rate of 100%.

Conclusion

Various debranching solutions for different complex scenarios of the aortic arch serve as less invasive procedures than conventional open surgery enabling safe and effective treatment of this highly selected subgroup of patients with complex aortic pathologies.     

PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging

Introduction:

In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage.

Study objective:

The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI.

Design:

We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area.

Discussion:

We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk.     

Complete video-assisted thoracoscopic surgery for pulmonary sequestration

Objective

To analyze the characteristics and technical difficulties of complete video-assisted thoracoscopic surgery (c-VATS) for treatment of pulmonary sequestration operation.

Methods

25 cases of c-VATS lobectomy for intrapulmonary sequestration performed between January 2009 and May 2012 were reviewed. The 25 patients included 13 (52%) males and 12 (48%) females, with a mean age of 34.7 years (range, 16-62 years). Preoperative imaging by CT scan and three-dimensional reconstruction of abnormal blood vessels diagnosed 19 cases as pulmonary sequestration, misdiagnosed 1 case as pulmonary cyst syndrome, 4 cases as bronchiectasis and 1 case as benign tumor.

Results

All the patients underwent c-VATS excision, 16 in the left lower lobe, 7 in the right lower lobe, 1 in right middle lobe and 1 extralobar pulmonary sequestration. Vascular abnormality was observed intraoperative including the thoracic aorta in 20 cases, abdominal aorta in 2 cases, phrenic arteries and intercostal artery in 1 cases and thoracic aorta combined with abdominal aorta in 1 case. No conversion to open was achieved in all cases. The mean operating time was 114.2 mins (range, 78-156 mins), the mean blood loss was 228 mL (range, 50-3,000 mL), the mean duration of chest drainage was 3.2 days (range, 2-7 days) and the mean length of post-operative hospital stay was 6.6 days (range, 3-13 days). There was no mortality, without significant postoperative complications, were cured and discharged. Patients were followed up for 2-32 months, mean 21.4 months, with no recurrence.

Conclusions

c-VATS is feasible, effective, and safe in treatment of pulmonary sequestration. It is worthy of clinical application.KEY WORDS : Complete video-assisted thoracoscopic surgery (c-VATS), pulmonary sequestration, treatment     

Role of TGF-β1/Smads pathway in carotid artery remodeling in renovascular hypertensive rats and prevention by Enalapril and Amlodipine

Objective To investigate the role of transforming growth factor-β1 (TGF-β1), Smad2/3 and Smad7 expressions in carotid artery remodeling in renovascular hypertensive rats, and also the therapeutic effect of Enalapril and Amlodipine. Methods The renovascular hypertensive rat (RHR) models with “two-kidney and one-clip” were established, including model group (n = 6), sham-operated group (n = 6), Enalapril group (10 mg/kg per day, n = 6), Amlodipine group (5 mg/kg per day, n = 6) and combination group (Amlodipine 2.5 mg/kg per day + Enalapril 5mg/kg per day, n = 6). The medication were continuous administrated for six weeks. Carotid artery morphological and structural changes in the media were observed by HE staining, Masson staining and immuno histochemical staining. Media thickness (MT), MT and lumen diameter ratio (MT/LD), and the expression levels of media α-smooth muscle actin (α-actin), proliferating cell nuclear antigen (PCNA), TGF-β1, phosphorylated Smad2/3 (p-Smad2/3) and Smad7 in carotid arteries were measured. Results The media of carotid arteries in RHR model group was significantly thickened, the volume of smooth muscle cell was increased, and the array was in disorder; MT, MT/LD, the proliferation index of smooth muscle cell and collagen fiber area percentage of carotid arteries in the model group were significantly higher than those in the sham-operated group (P < 0.01). Compared to sham-operated group, the model group had significantly higher expressions of TGF-β1 and p-Smad2/3 (P < 0.05) and lower Smad7 expression. Both Enalapril and Amlodipine improved smooth muscle hypertrophy and collagen deposition, reduced RHR carotid MT, MT/LD, proliferation index of smooth muscle cell, collagen fiber area percentage and the expressions of TGF-β1 and p-Smad2/3 (P < 0.05), increased Smad7 expression (P < 0.05). Moreover, the combination treatment of Enalapril and Amlodipine had significantly better effects than single Amlodipine group (P < 0.05), but not single Enalapril group. Conclusions TGF-β1/Smads pathway may participate in the mechanism of carotid artery remodeling in RHR; the role of Amlodipine and Enalapril in inversing carotid artery remodeling may be related to the change of TGF-β1/Smads pathway, the combination treatment of Amlodipine and Enalapril had better effects than single administration of Amlodipine.     

Carotid artery stenting in asymptomatic and surgically high-risk patients: single-centre, single-operator results

BACKGROUND:

Stroke represents the third leading cause of death in developed countries and the leading cause of disability in the elderly. Because asymptomatic, surgically high-risk patients have been systematically excluded from randomized trials of carotid endarterectomy and medical therapy, the management of this group of patients is still controversial. A single-centre, single-operator registry was analyzed to evaluate feasibility and safety of carotid artery stenting (CAS) with distal protection devices in consecutive, asymptomatic, surgically high-risk patients who were scheduled for endovascular treatment of significant carotid stenoses.

METHODS:

A total of 122 consecutive, surgically high-risk, asymptomatic patients (150 carotid arteries, 59% men, mean [± SD] age 69±9 years) with severe carotid stenosis and one or more high-risk features for carotid endarterectomy were scheduled for CAS. All procedures were performed in a single centre by a single operator. All patients were prospectively asked to undergo a clinical 30-day follow-up.

RESULTS:

A total of 154 stents were implanted in 150 carotid arteries. The primary success rate was 98.7%. The rates of stenosis before and after direct CAS were 81%±9% and 10%±13%, respectively. The median of fluoroscopic time of direct CAS was 6 min (range 2.5 min to 31.5 min). At 30 days, data were available in all patients. The combined 30-day mortality and stroke rate was 1.3%.

CONCLUSIONS:

Short-term outcomes of CAS in asymptomatic, surgically high-risk patients treated by a single operator suggest a low periprocedural complication rate.     

The primary anomalies of coronary artery origin and course: A coronary angiographic analysis of 16,573 patients

BACKGROUND/OBJECTIVES:

Coronary artery anomalies are present at birth, but relatively few are symptomatic. The majority are discovered incidentally. In the present study, coronary angiograms performed in the authors’ centre (Ondokuz Mayis University Hospital, Samsun, Turkey) were analyzed to determine the prevalence and types of coronary artery origin and course anomalies.

METHODS:

Coronary angiographic data of 16,573 patients were analyzed. Anomalous origins and courses of coronary arteries were assessed.

RESULTS:

Anomalous coronary arteries were detected in 48 (0.29%) of 16,573 patients. The origin of the circumflex (Cx) artery from the right coronary artery (RCA) or right sinus of Valsalva was the most common anomaly (28 patients [58.3%]). An anomalous RCA originating from the left anterior descending artery (LAD) or Cx artery was observed in six patients (12.5%). The left coronary artery originated from the right sinus of Valsalva in five patients, and the LAD originated from the RCA or the right sinus of Valsalva in five patients. The RCA originated from the left sinus of Valsalva in three patients and from an ectopic ostium in the ascending aorta in one patient.

CONCLUSIONS:

The most frequent anomaly observed in the present study was related to the Cx artery, which is consistent with previous reports. Although coronary artery anomalies are rare, they may cause difficulties during coronary interventions or cardiac surgery and may occasionally result in sudden cardiac death. Therefore, the recognition and diagnosis of these anomalies is important and requires specialization in coronary angiographic techniques and other imaging modalities.     

Effects of Skeletonized versus Pedicled Radial Artery on Postoperative Graft Patency and Flow

Background

Radial artery (RA) was the second arterial graft introduced in clinical practice for myocardial revascularization. The skeletonization technique of the left internal thoracic artery (LITA) may actually change the graft''s flow capacity with potential advantages. This leads to the assumption that the behavior of the RA, as a coronary graft, is similar to that of the LITA, when skeletonized.

Objective

This study evaluated ''free'' aortic-coronary radial artery (RA) grafts, whether skeletonized or with adjacent tissues.

Methods

A prospective randomized study comparing 40 patients distributed into two groups was conducted. In group I, we used skeletonized radial arteries (20 patients), and in group II, we used radial arteries with adjacent tissues (20 patients). After the surgical procedure, patients underwent flow velocity measurements.

Results

The main surgical variables were: RA internal diameter, RA length, and free blood flow in the radial artery. The mean RA graft diameters as calculated using quantitative angiography in the immediate postoperative period were similar, as well as the flow velocity measurement variables. On the other hand, coronary cineangiography showed the presence of occlusion in one RA graft and stenosis in five RA grafts in GII, while GI presented stenosis in only one RA graft (p = 0.045).

Conclusion

These results show that the morphological and pathological features, as well as the hemodynamic performance of the free radial artery grafts, whether prepared in a skeletonized manner or with adjacent tissues, are similar. However, a larger number of non-obstructive lesions may be observed when RA is prepared with adjacent tissues.     

Altered energy supply to the pump function of the isolated heart of spontaneously hypertensive rats

OBJECTIVE:

The reasons for the development of cardiac insufficiency after a prolonged period of compensation accompanying myocardial hypertrophy are still uncertain and a disturbance in the energy metabolism of cardiomyocytes may serve as an underlying cause. The goal of the present work was to study functional and energetic correlates of the isolated heart of spontaneously hypertensive rats (SHR) at the stage of compensation.

METHODS:

Isolated hearts of SHR and normotensive age-matched Wistar-Kyoto (WKY) rats were subjected to volume and resistance loads. The myocardial content of high-energy phosphates and creatine was determined both before and after the functional loads.

RESULTS:

The contractile performances of the SHR hearts was significantly higher than those of the WKY hearts, the maximal cardiac output during volume load was higher by 36% and the maximal cardiac work index at complete aortic clamping was 68% higher. However, because the dry weight of SHR hearts was 48% higher, the normalized functional indices did not differ significantly between the groups. The ATP-to-ADP ratio and the total creatine level were significantly lower by 10% to 13% in the SHR group before and after the functional loads. In addition, the total adenine nucleotide pool and ATP content were 17% to 20% lower in SHR hearts after the functional loads. The content of high-energy phosphates correlated with contractile indices in the WKY group but not in the SHR group.

CONCLUSIONS:

The results showed that the SHR hearts were better adapted to increased loads than the WKY hearts; however, this advantage combines with an altered interrelation between myocardial energy state and its function.     

Myocardial Revascularization in Dyalitic Patients: In-Hospital Period Evaluation

Background

Coronary artery bypass grafting currently is the best treatment for dialytic patients with multivessel coronary disease, but hospital morbidity and mortality related to procedure is still high.

Objective

Evaluate results and in-hospital outcomes of coronary artery bypass grafting in dialytic patients.

Methods

Retrospective unicentric study including 50 consecutive and not selected dialytic patients, who underwent coronary artery bypass grafting in a tertiary university hospital from 2007 to 2012.

Results

High prevalence of cardiovascular risk factors was observed (100% hypertensive, 68% diabetic and 40% dyslipidemic). There was no intra-operative death and 60% of the procedures were performed off-pump. There were seven (14%) in-hospital deaths. Postoperative infection, previous heart failure, cardiopulmonary bypass, abnormal ventricular function and surgical re-exploration were associated with increased mortality.

Conclusion

Coronary artery bypass grafting is feasible to dialytic patients although high in-hospital morbidity and mortality. It is necessary better understanding about metabolic aspects to plan adequate interventions.     

Could a high-fat diet rich in unsaturated fatty acids impair the cardiovascular system?

BACKGROUND:

Dyslipidemia results from consumption of a diet rich in saturated fatty acids and is usually associated with cardiovascular disease. A diet rich in unsaturated fatty acids is usually associated with improved cardiovascular condition.

OBJECTIVE:

To investigate whether a high-fat diet rich in unsaturated fatty acids (U-HFD) – in which fatty acid represents approximately 45% of the total calories – impairs the cardiovascular system.

METHODS:

Male, 30-day-old Wistar rats were fed a standard (control) diet or a U-HFD containing 83% unsaturated fatty acid for 19 weeks. The in vivo electrocardiogram, the spectral analysis of heart rate variability, and the vascular reactivity responses to phenylephrine, acetylcholine, noradrenaline and prazosin in aortic ring preparations were analyzed to assess the cardiovascular parameters.

RESULTS:

After 19 weeks, the U-HFD rats had increased total body fat, baseline glucose levels and feed efficiency compared with control rats. However, the final body weight, systolic blood pressure, area under the curve for glucose, calorie intake and heart weight/final body weight ratio were similar between the groups. In addition, both groups demonstrated no alteration in the electrocardiogram or cardiac sympathetic parameters. There was no difference in the responses to acetylcholine or the maximal contractile response of the thoracic aorta to phenylephrine between groups, but the concentration necessary to produce 50% of maximal response showed a decrease in the sensitivity to phenylephrine in U-HFD rats. The cumulative concentration-effect curve for noradrenaline in the presence of prazosin was shifted similarly in both groups.

CONCLUSIONS:

The present work shows that U-HFD did not impair the cardiovascular parameters analyzed.     

Study of the intima-media thickening in carotid arteries of healthy elderly with high blood pressure and elderly with high blood pressure and dyslipidemia

Objective

The objective of this study was to assess the mean intima-media thickening of carotid arteries of elderly subjects, and its relationship with age, anthropometric measurements, high systolic blood pressure and dyslipidemia.

Methods

In this investigation, 129 subjects were enrolled between 1995 and 1998, age ranging from 29 to 94 years. They were assigned to one of 4 groups, including 2 control groups (group I, of healthy younger subjects; group II of healthy elderly subjects). Groups III and IV included those who presented with isolated systolic hypertension (ISH), and ISH and dyslipidemia, respectively. All subjects were submitted to a medical interview, lab tests with measurement of cholesterol levels, electrocardiogram, and carotid ultrasound. The ultrasound included measurement of the intima-media thickening (IMT) of the carotid arteries, the right carotid artery (RCA) and left carotid artery (LCA), and assessment of the presence of plaques. Blood fat and glucose were measured by a standard method. The results were compared among the groups through statistical tests. The tests employed were: Chi-Square, Pearson’s and Likelihood Ratio, Student’s t, Mann-Whitney; ANOVA followed by Tukey’s test, Kruskal-Wallis nonparametric test, and test for multiple comparisons and Odds Ratio determination (OR).

Results

In this investigation, a positive association was observed between aging and IMT. In relation to systolic hypertension, a significant association was observed with IMT (IMT-RCA p = 0.0034; IMT-LCA p = 0.0196; IMT-RLCA p = 0.0299), and with the presence of plaques (PlaqueR p = 0.0110; PlaqueL p = 0.0294; PlaqueRL p = 0.0040).

Conclusion

This investigation evidenced the important role of aging in IMT, and of systolic hypertension in the IMT and presence of plaque. However, further studies are needed for a better understanding of the actual role of risk factors in aging.     

Effects of One Resistance Exercise Session on Vascular Smooth Muscle of Hypertensive Rats

Background

Hypertension is a public health problem and increases the incidence of cardiovascular diseases.

Objective

To evaluate the effects of a resistance exercise session on the contractile and relaxing mechanisms of vascular smooth muscle in mesenteric arteries of N^G-nitro L-arginine methyl ester (L-NAME)-induced hypertensive rats.

Methods

Wistar rats were divided into three groups: control (C), hypertensive (H), and exercised hypertensive (EH). Hypertension was induced by administration of 20 mg/kg of L-NAME for 7 days prior to experimental protocols. The resistance exercise protocol consisted of 10 sets of 10 repetitions and intensity of 40% of one repetition maximum. The reactivity of vascular smooth muscle was evaluated by concentration‑response curves to phenylephrine (PHEN), potassium chloride (KCl) and sodium nitroprusside (SNP).

Results

Rats treated with L-NAME showed an increase (p < 0.001) in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) compared to the initial period of induction. No difference in PHEN sensitivity was observed between groups H and EH. Acute resistance exercise reduced (p < 0.001) the contractile response induced by KCl at concentrations of 40 and 60 mM in group EH. Greater (p < 0.01) smooth muscle sensitivity to NPS was observed in group EH as compared to group H.

Conclusion

One resistance exercise session reduces the contractile response induced by KCl in addition to increasing the sensitivity of smooth muscle to NO in mesenteric arteries of hypertensive rats.     

Genetic and Environmental Effects on the Abdominal Aortic Diameter Development

Background

Configuration of the abdominal aorta is related to healthy aging and a variety of disorders.

Objectives

We aimed to assess heritable and environmental effects on the abdominal aortic diameter.

Methods

114 adult (69 monozygotic, 45 same-sex dizygotic) twin pairs (mean age 43.6 ± 16.3 years) underwent abdominal ultrasound with Esaote MyLab 70X ultrasound machine to visualize the abdominal aorta below the level of the origin of the renal arteries and 1-3 cm above the bifurcation.

Results

Age- and sex-adjusted heritability of the abdominal aortic diameter below the level of the origin of the renal arteries was 40% [95% confidence interval (CI), 14 to 67%] and 55% above the aortic bifurcation (95% CI, 45 to 70%). None of the aortic diameters showed common environmental effects, but unshared environmental effects were responsible for 60% and 45% of the traits, respectively.

Conclusions

Our analysis documents the moderate heritability and its segment-specific difference of the abdominal aortic diameter. The moderate part of variance was explained by unshared environmental components, emphasizing the importance of lifestyle factors in primary prevention. Further studies in this field may guide future gene-mapping efforts and investigate specific lifestyle factors to prevent abdominal aortic dilatation and its complications.     

Aortic dissection after open repair of an infrarenal aortic aneurysm

INTRODUCTION:

A case of thoracic-abdominal dissection after open surgical exclusion of an infrarenal aortic aneurysm is presented.

CASE PRESENTATION:

A 62-year-old woman was diagnosed with an infrarenal abdominal aortic aneurysm with a rapid increase in maximal diameter. She underwent surgery for aneurysm exclusion by an end-to-end aortoaortic bypass with Dacron collagen (Intervascular; WL Gore & Associates Inc, USA). After 15 days, she was admitted to the emergency department with intense epigastric and lumbar pain. Computed tomography angiography with contrast revealed an aortic dissection with origin in the proximal bypass anastomosis and cranial extension to the thoracic aorta. The true lumen at the level of the eighth thoracic vertebra was practically collapsed by the false lumen. The celiac trunk, and the mesenteric and renal arteries were perfused by the true lumen. After the acute phase of the aortic dissection, surgical repair was planned. Two paths of false lumen were found – one at the thoracic aorta and the second in the proximal bypass anastomosis. Surgical repair comprised two approaches. First, a Valiant Thoracic stent graft (Medtronic Inc, UK) was implanted distal from the left subclavian artery, expanding the collapsed true lumen and covering the false and dissected lumen. Second, an infrarenal Endurant abdominal stent graft (Medtronic Inc) was implanted. This second device was complemented with an aortic infrarenal extension using a Talent abdominal stent graft (Medtronic Inc) in the infrarenal aortic neck to achieve a hermetic seal. The postoperative clinical course was uneventful, and her symptoms were completely resolved in six months.

CONCLUSION:

Arteritis must be taken into account in young patients with high inflammatory markers. Covered stents and endoprosthetic devices seem to be effective methods to seal the dissected lumen.     

An analysis of the risk factors for premature coronary artery disease in young and middle-age Chinese patients with hypertension

BACKGROUND:

Hypertension has become prevalent among young and middle-age individuals. Many studies have identified a variety of risk factors for cardiovascular diseases, yet there have been few reports focusing on the young and middle-age hypertensive population.

OBJECTIVE:

To investigate the epidemiological characteristics of conventional risk factors of premature coronary artery disease (PCAD) in patients with hypertension.

METHODS:

The clinical and laboratory data of 267 hypertensive patients with PCAD and 96 hypertensive patients without any visible coronary disease according to angiography were compared. Potential coronary risk factors were analyzed using logistic regression.

RESULTS:

The PCAD group had lower levels of high-density lipoprotein cholesterol (HDL-C) (P<0.05). Multivariate logistic analysis showed positive family history, low HDL-C, hypertriglyceridemia, duration of diabetes mellitus and male sex were significantly associated with PCAD (P<0.05), with ORs of 12.317, 3.267, 2.894, 1.140 and 0.088, respectively. Plasma renin activities in PCAD patients were significantly higher than in control hypertensive patients (P=0.027), but there was no significant difference in angiotensin II and aldosterone levels between the two groups.

CONCLUSION:

Low HDL-C and hypertriglyceridemia are important coronary risk factors in Chinese individuals with hypertension.     

Correlation Between the Intima-Media Thickness of the Proximal and Distal Common Carotids

Background

Increased IMT (intima-media thickness) in carotids is used as an early atherosclerosis marker and to evaluate the risk of cardiovascular problems. Ultrasound is used in the evaluation because it is accessible and low cost. Measurements for different carotid regions are described.

Objective

To compare the proximal and distal region IMTs for the bilateral common carotid and guide its use in clinical practice.

Methods

The IMT was measured in the proximal and distal common carotid arteries of 798 individuals (35-74 years old) of both genders using high-resolution ultrasound. Pearson''s correlation coefficient was used to establish associations. The analyses were initially performed for the entire sample as well as subgroups with IMT <0.90 mm (49% of the sample) and ≥0.90 mm for at least one measurement site. The statistical significance was p < 0.05.

Results

The correlations investigated were significant. In the group with an IMT <0.90 mm, the correlations were between 0.44 and 0.62. In the subgroup with an IMT ≥0.90 mm, the correlations were significantly reduced to between 0.20 and 0.40.

Conclusion

The data suggest that the IMT is more uniform along the carotid during early development and tends develop focally as it progresses. Therefore, in clinical evaluations of patients, the common carotid length should be investigated bilaterally to better use the available software and discern the IMT.