Nachum Nesher

Should Bilateral Internal Thoracic Artery Grafting Be Used in Elderly Patients Undergoing Coronary Artery Bypass Grafting

Background— Although bilateral internal thoracic artery grafting is associated with improved survival, the use of this technique in the elderly is controversial because of their increased surgical risk and shorter life expectancy. The purpose of this study was to evaluate the effect of age on outcome of patients undergoing bilateral internal thoracic artery grafting. Methods and Results— Between 1996 and 2001, 1714 consecutive patients underwent skeletonized bilateral internal thoracic artery grafting, of whom 748 were ⩽65 years of age, 688 were between 65 and 75 years of age, and 278 were ≥75 years of age. Operative mortality of the 3 age groups (1.2%, 4.1%, and 5.8%, respectively) was lower than the logistic EuroSCORE predicted mortality (3.9%, 6.5%, and 9.3%, respectively; P<0.001). There were no significant differences among the groups in occurrence of sternal infection (1.3%, 2.6%, and 1.4%, respectively; P=0.171). Mean follow-up was 11.5 years. Kaplan–Meier 10-year survival for patients ⩽65, 65 to 75, and >75 years of age was 85%, 65%, and 40%, respectively (P<0.001). These rates were better than the corresponding predicted Charlson Comorbidity Index survival rates (68%, 37%, and 20%, respectively; P<0.001 for all age groups), approaching survival of the sex- and age-matched general population (90%, 70%, and 41%, respectively). Age ⩽65 years (hazard ratio, 0.232; 95% confidence interval, 0.188–0.288) and age 65 to 75 years (hazard ratio, 0.499; 95% confidence interval, 0.414–0.602) were independent predictors of improved survival (Cox model). Conclusions— Bilateral internal thoracic artery grafting should be considered in patients >65 years of age because of the significant survival benefit obtained with this surgical technique with no additional risk of sternal wound infection related to age.

Pulmonary Hypertension: A Nomogram Based on CT Pulmonary Angiographic Data for Prediction in Patients without Pulmonary Embolism

PURPOSE To use cardiovascular data from computerized tomographic (CT) pulmonary angiography for facilitating the identification of pulmonary hypertension (PH) in patients without acute pulmonary embolism. MATERIALS AND METHODS The institutional human research committee approved this retrospective study; informed consent was waived. Patients without pulmonary embolism who underwent CT pulmonary angiography and echocardiography within 24 hours of each other between December 2008 and October 2012 were retrospectively identified. The diameters of the pulmonary artery, aorta, and right and left ventricles and the severity of reflux of contrast material were assessed. The volumes of each cardiac compartment were calculated. Doppler echocardiography served as a reference standard for PH. A prediction model for PH was built by using backward logistic regression and was presented on a nomogram. The prediction model was evaluated with 10-fold cross-validation, and a test group of patients was studied between November 2012 and June 2014. RESULTS The final study group included 182 patients, of whom 98 (54%) were given a diagnosis of PH on the basis echocardiographic results. Age of 67 years or older (odds ratio [OR] = 4.46), reflux grade of 3 or higher (OR = 2.63), right atrial volume of greater than or equal to 106 cm(3) (OR = 3.59), pulmonary artery diameter greater than or equal to 28 mm (OR = 2.52) and pulmonary artery diameter to aorta diameter ratio of greater than or equal to 0.86 (OR = 2.17) were independently associated with PH. The logistic model showed good discrimination ability (area under the curve = 0.844, discrimination slope = 0.359). Tenfold cross-validation showed 85.7% sensitivity, 60.7% specificity, 71.3% positive predictive value, and 76.1% negative predictive value for identification of PH, while the test group showed similar results (84.1%, 60.5%, 71.2%, and 76.7%, respectively). CONCLUSION Cardiovascular data derived from CT pulmonary angiography are associated with PH, and a nomogram can be created that may facilitate identification of PH after exclusion of acute pulmonary embolism.

l-Arginine improves endothelial function, independently of arginine uptake, in aortas from chronic renal failure female rats

Endothelial cell dysfunction (ECD) is a common feature of chronic renal failure (CRF). Defective nitric oxide (NO) generation due to decreased endothelial nitric oxide synthase (eNOS) activity is a crucial parameter characterizing ECD. Decreased activity of cationic amino acid transporter-1 (CAT-1), the selective arginine transporter of eNOS, has been shown to inhibit eNOS in uremia. Recently, we failed to demonstrate a decrease in glomerular arginine transport in uremic female rats (Schwartz IF, Grupper A, Soetendorp H, Hillel O, Laron I, Chernichovski T, Ingbir M, Shtabski A, Weinstein T, Chernin G, Shashar M, Hershkoviz R, Schwartz D. Am J Physiol Renal Physiol 303: F396-F404, 2012). The current experiments were designed to determine whether sexual dimorphism which characterizes glomerular arginine transport system in uremia involves the systemic vasculature as well and to assess the effect of L-arginine in such conditions. Contractile and vasodilatory responses, ultrastructural changes, and measures of the L-arginine-NO system were performed in thoracic aortas of female rats subjected to 5/6 nephrectomy. The contractile response to KCl was significantly reduced, and acetylcholine-induced vasodilation was significantly impaired in aortas from CRF dames compared with healthy rats. Both of these findings were prevented by the administration of arginine in the drinking water. The decrease in both cGMP generation, a measure of eNOS activity, and aortic eNOS and phosphorylated eNOS abundance observed in CRF rats was completely abolished by l-arginine, while arginine transport and CAT-1 protein were unchanged in all experimental groups. Arginine decreased both serum levels of advanced glycation end products and the asymmetrical dimethylarginine/arginine ratio and restored the endothelial ultrastructure in CRF rats. In conclusion. arginine administration has a profound beneficial effect on ECD, independently of cellular arginine uptake, in CRF female rats.

Obstacles in the Diagnosis of Acute Aortic Dissection

Acute aortic dissection (AAD) is a life-threatening condition for which prompt diagnosis is essential for successful management. The imaging modalities for demonstrating the dissecting membrane include retrograde aortography, contrast-enhanced computed tomography (CT), transesophageal echocardiography (TEE), and magnetic resonance imaging. Of these, aortography had long been considered the gold standard in diagnosing aortic dissection. We present a case of AAD in which contrast-enhanced CT and retrograde aortography failed to demonstrate an aortic membranous flap, whereas TEE swiftly provided clear-cut evidence of the pathology. TEE should be considered when AAD is suspected despite negative findings on other imaging modalities.